# 120/208v why?



## 480sparky (Sep 20, 2007)

It's all about phase angles.


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## alselec53 (Jan 4, 2012)

*120/208v*

Yes, but why the 208v? and why the wild leg? what is it used for? Homes use 120/240v. I know some things run on both, but why have 2 voltages so close?


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## 480sparky (Sep 20, 2007)

alselec53 said:


> Yes, but why the 208v? and why the wild leg? what is it used for? Homes use 120/240v. I know some things run on both, but why have 2 voltages so close?



Again... it's phase angles. It's a function of _electrical _math.

Since 120/208 is three-phase, the phases are 120° apart. If they were 180° apart (like a 120/240 single phase system). then it would be 120/240 3/phase. But since they're 120° apart, the voltage is 240 * sin(120).


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## butcher733 (Aug 4, 2012)

Are you self taught? I'm curious as to how you have made it this far without this information. I don't mean this disrespectfully, everybody's path is different.


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## HawkShock (Nov 27, 2012)

Google is your friend. Or search feature. 3 phase gives you 208/120 because it isn't single phase. If you want a better answer, google it and ask questions from there.


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## hardworkingstiff (Jan 22, 2007)

alselec53 said:


> Been in the trade for years and always wondered why they use 120/208v in commercial and 120/240 in residential. Plus with different transformers y, delta, 3 ph you have 120v to ground on 2 of the phases and 208v to grd on the last phase. Why the 120/208v, and why the wild led? in commercial?


Well as far as I know, single-phase transformers are less expensive, plus they only require the PoCo to bring 1 phase conductor and the neutral to the transformer. So when you are wiring a small neighborhood, you can use just 2 conductors instead of bringing in 4. So, basically, single-phase is less expensive to install. Unless you need 3-phase, you will mostly have single-phase.

The Delta 3-phase feed to a building can be supplied with 2 phase conductors and a neutral, and just 2 transformers. It was mostly used where a customer had 1 or 2 3-phase pieces of equipment and everything else would work great on single-phase. 

I don't see any new Delta services. I believe the PoCo finally figured out that in the long run, it's better to install a Wye service than a Delta service. Why, I'm not sure. My guess would be it's easier to balance their loads and they can keep fewer types of transformers on hand for emergency replacements.


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## alselec53 (Jan 4, 2012)

*120/208v*



butcher733 said:


> Are you self taught? I'm curious as to how you have made it this far without this information. I don't mean this disrespectfully, everybody's path is different.


No, no, I've been through electronics, elec work for years, not saying I know it all, but, I know about single & 3 phase and the efficiency factor. I'm wondering why 208v, and why 208v wild leg (which would be single phase actually), think your missing the question.


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## 480sparky (Sep 20, 2007)

Start here.


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## HawkShock (Nov 27, 2012)

It is 208v 3phase because you still get 120v to ground. Don't understand what you are asking...


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## hardworkingstiff (Jan 22, 2007)

alselec53 said:


> No, I know about single & 3 phase and the efficientcy factor. I'm wondering why 208v, and why 208v wild leg (which would be single phase actually), think your missing the question.


The 208 high leg is part of a 240V 3-phase Delta distribution system with a center tap between the other 2 legs (not the 208 leg). Here you are reading phase conductor to neutral and you really should not use this leg in conjunction with the neutral.

The other 208V you speak of is between 2 ungrounded conductors of a Wye distribution system, and you have 120V to neutral from either conductor.


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## alselec53 (Jan 4, 2012)

*120/208v*



HawkShock said:


> It is 208v 3phase because you still get 120v to ground. Don't understand what you are asking...


Yes, don't think my question is worded right, might have to google it.


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## hardworkingstiff (Jan 22, 2007)

HawkShock said:


> . Don't understand what you are asking...





alselec53 said:


> Yes, don't think my question is worded right, might have to google it.


I'm beginning to think you don't really understand your question. I know we don't.


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## ohmontherange (May 7, 2008)

Read up on transformers.


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## 480sparky (Sep 20, 2007)

alselec53 said:


> Yes, don't think my question is worded right, might have to google it.


Google "electrical math" and "phase angles".


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## ohmontherange (May 7, 2008)

480sparky said:


> Google "electrical math" and "phase angles".


A gal once told me the angle of the dangle is relative to the heat of the meat. 

Think it had something to do with grilling or smoking...:laughing:


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## micromind (Aug 11, 2007)

120/240 commonly found in resi is a single phase system. Two hots and a neutral. 

120/208 is a 3ø system. 3 hots and a neutral. There are basically 3 reasons why 120/208 is used in commercial/industrial.

1) If the service is 480, the only way to get 120 is with a transformer. If the transformer is single phase, it uses two of the 3 phases of the 480. This could result in an imbalance that would have a bad effect on 480 3ø motors. A small single phase transformer (usually 10KVA or less) won't have much of an effect on phase balance. A larger one can.

2) With a single phase system, two hots can share a neutral. With a 120/208 system, 3 hots can share a neutral.

3) For the same amount of power (watts) a 120/208 system can usually have smaller wire. 

A 120/208 system is wye connected. This means that each phase will have 120 to neutral/ground and 208 between any two of them. 

The best way I can think of to describe a 120/240∆ system would be to think of it as single phase with a third phase added on.


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## micromind (Aug 11, 2007)

120/240 commonly found in resi is a single phase system. Two hots and a neutral. 

120/208 is a 3ø system. There are basically 3 reasons why 120/208 is used in commercial/industrial.

1) If the service is 480, the only way to get 120 is with a transformer. If the transformer is single phase, it uses two of the 3 phases of the 480. This could result in an imbalance that would have a bad effect on 480 3ø motors. A small single phase transformer (usually 10KVA or less) won't have much of an effect on phase balance. A larger one can.

2) With a single phase system, two hots can share a neutral. With a 120/208 system, 3 hots can share a neutral.

3) For the same amount of power (watts) a 120/208 system can usually have smaller wire. 

A 120/208 system is wye connected. This means that each phase will have 120 to neutral/ground and 208 between any two of them. 

The best way I can think of to describe a 120/240∆ system would be to think of it as single phase with a third phase added on.


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## Vintage Sounds (Oct 23, 2009)

The 120/240v ∆ has a few advantages over the 120/208Y. Probably not enough to make it the system of choice for most places, but still.

You get higher system voltage, 240 vs 208. 
You get a delta, which is cool because if one winding of your delta transformer somehow failed open, you would still have 3 phase power available for your motors, just with reduced total system capacity. If this occurred in a wye system the motors would single phase and burn out unless they had single phasing protection installed.
Not only do you get a delta but you get a delta that doesn't require any kind of ground fault detection apparatus. The system is ground referenced.
You still have 120v available for receptacles, lighting etc.

The only downside is the high leg which makes life hard if you have tons of single phase stuff.


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## erics37 (May 7, 2009)

A picture is worth a thousand words.










I've always liked the description for the primary side of this transformer :laughing:










The first picture is of two different 3-phase configurations; the first is a 120/208 Wye system. You can see that the voltages relative to each other and to neutral all correlate to the configuration of the transformer windings involved. The second is a 240/120 3-phase Delta system with a high leg. Unlike the Wye, there is no common point from which to tap a neutral conductor, so they just pick a phase and put a center tap in it and ground it. Voila, a neutral. But as you can see, it is 208 to ground to the opposite phase. Just the way things work out.

The second picture is a standard 240/120 residential service transformer If you compare it to the Delta high-leg, you can see that it looks the same as the high-leg tapped winding if it were installed by itself. Pretty much the same deal.


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## bobelectric (Feb 24, 2007)

Become a plumber.


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## Big John (May 23, 2010)

HawkShock said:


> It is 208v 3phase because you still get 120v to ground. Don't understand what you are asking...


 I think that's probably part of what he's asking. Why not wire it to be 3Ø 240 and that's the reason, because while it can be done, your phase angles are fixed and it changes your line-to-neutral voltage for single-phase loads.


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## micromind (Aug 11, 2007)

Big John said:


> I think that's probably part of what he's asking. Why not wire it to be 3Ø 240 and that's the reason, because while it can be done, your phase angles are fixed and it changes your line-to-neutral voltage for single-phase loads.


Good point.

In a wye connected 3ø system, the line to line voltage is always 1.732 X the line to neutral. 

A wye system always has the same voltage to neutral on all 3 phases, a delta does not. 

If you made a wye with 240 phase to phase, you'd have 139 phase to neutral.


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## 220/221 (Sep 25, 2007)

butcher733 said:


> Are you self taught? I'm curious as to how you have made it this far without this information. I don't mean this disrespectfully, everybody's path is different.


I am one of those self taught guys. I don't comprehend phase angles. Hell, I still can't _quite_ understand AIC. 

What I do is simply *accept that there are things I won't understand*. I know that there are different systems like Wye and Delta and I know how to identify and work with them. I don't need to know how they are created.

I mean, I don't need to know how a computer works to tell Badger he's a douche . :thumbup:


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## BBQ (Nov 16, 2010)

220/221 said:


> I mean, I don't need to know how a computer works to tell Badger he's a douche . :thumbup:


Feeling a little inadequate 220?


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## Tiger (Jan 3, 2008)

We need pictures of 1PH & 3PH sine waves to complete the confusion.


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## 220/221 (Sep 25, 2007)

BBQ said:


> Feeling a little inadequate 220?


Rarely. I've been able to accept my limitations for a long, long time now. I may be delusional but I consider it a sign of good character. ( edit...heh heh... accepting my limits, not being delusional :laughing

_Some people_ need to blah blah blah in a one sided conversation to try to convince others that they are smart. :laughing:


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## 480sparky (Sep 20, 2007)

220/221 said:


> I am one of those self taught guys. I don't comprehend phase angles.


Until you do, you won't understand 208 volts.



220/221 said:


> Hell, I still can't _quite_ understand AIC...........


Think of it this way: If you force enough amperage through a breaker, the breaker may simply fail to open the circuit. Guess what's gonna happen then?

An analogy might be an air compressor. This compressor might be capable of pumping the tank up to, say, 200 psi. But the _tank itself_ might be rated at 800 psi. That 800psi is well above what the pump is capable of putting out, so the tank shouldn't blow up.

Breakers have an AIC rating this is above what a short-circuit current should be. Short circuits _in theory_ have an infinite current flow. But in real life, it's well below that. Most residential transformers can kick out 10,000 or 15,000 amps. So by having breakers capable of opening the circuit even at 22,000 amps is a 'buffer'... a 'safety margin': just like the 800-psi-rated tank on a 200 psi compressor.

Should there be a short circuit across the buss bars of the panel (some dumb handyman drops his screwdriver), even with 15,000 amps flowing, the main should open. With the compressor analogy, let's say the pressure switch fails and the pump doesn't shut off: The pump might get the air pressure up to 300 or 400 psi, but the tank shouldn't blow up.

You literally over-engineer the device, and err towards the side of safety.


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## 220/221 (Sep 25, 2007)

480sparky said:


> Until you do, you won't understand 208 volts.


 
My point is that I don't need to understand it. Much like a computer, I only need to understand it's functionality.

Same with AIC. I understand all the words that have been told to me a dozen times but some part of it escapes me. 

I can live with that. I know enough **** :thumbup:

My job is to provide a path for the electrons from point A to point B as efficiently ($$$) as possible.

As far as AIC, I understand the concept...the words...but to fully understand, my brain needs to have an example of a 10,000 amp short or a 22,000 amp short. Otherwise, it's just numbers.


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## FlatRateGator (Feb 13, 2013)

If you want a system that can deliver 120 V to ground AND operate 3-phase equipment, then the laws of physics dictate the 208 phase-to-phase voltage.

We can't separate the two. If we wanted a nice round phase-to-phase voltage like, say, 300 volts, we'd be _forced_ to have a phase to ground voltage of 173 V. So by choosing 120 V to ground, we are forced to have 208 p-to-p. In other words, we can choose only one voltage, the other is set by Mother Nature.


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## HawkShock (Nov 27, 2012)

220/221 said:


> My point is that I don't need to understand it. Much like a computer, I only need to understand it's functionality.
> 
> Same with AIC. I understand all the words that have been told to me a dozen times but some part of it escapes me.
> 
> ...


AIC rating means that it wont weld itself closed before it breaks. 10,000 AIC won't weld itself closed before 10,000 AIC. Phase to phase shorts pull an extreme amount of current so quickly you can't realize it. The time it takes for a breaker to trip is relative to the current being pushed through it, so it takes some time (milliseconds) for a breaker to trip, and by that time an immense amount of current can be drawn. So, the 10,000 AIC wil open provided the current being drawn doesn't exceed the AIC rating.


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## 220/221 (Sep 25, 2007)

HawkShock said:


> AIC rating means that it wont weld itself closed before it breaks.



Awesome, thanks!

Now, what condition(s) would cause a short of over 10,000 amps?


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## 480sparky (Sep 20, 2007)

220/221 said:


> My point is that I don't need to understand it. Much like a computer, I only need to understand it's functionality.
> 
> Same with AIC. I understand all the words that have been told to me a dozen times but some part of it escapes me.
> 
> ...


So its like you're asking what's the difference between a 4-stroke engine and a 2-stroke but don't want to be bothered with why one has 4 strokes and the other has just 2.


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## 480sparky (Sep 20, 2007)

220/221 said:


> Awesome, thanks!
> 
> Now, what condition(s) would cause a short of over 10,000 amps?


A handyman dropping his screwdriver onto the busses bars.


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## 220/221 (Sep 25, 2007)

480sparky said:


> So its like you're asking what's the difference between a 4-stroke engine and a 2-stroke but don't want to be bothered with why one has 4 strokes and the other has just 2.


That is simple mechanical stuff that I learned when I was 12 but, yeah. The guy cutting my lawn doesn't really need to know the mechanics. He only needs to know to put oil/gas in the 2 stroke. :thumbsup:



> A handyman dropping his screwdriver onto the busses bars.


Come on now. I'm not that bright but even *I* know that is not a true statement. There are too many variables in that scenario.


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## RandyM (Apr 5, 2012)

220/221 said:


> Awesome, thanks!
> 
> Now, what condition(s) would cause a short of over 10,000 amps?


The poco transformer is on the other side of the wall from your panel vs 200' away on the far side if the lot.

I have some estimates from poco of 16,000 amps! 

A 65K rated breaker vs a 18K has a heavier case so it won't blow up on a short.


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## HawkShock (Nov 27, 2012)

220/221 said:


> Come on now. I'm not that bright but even *I* know that is not a true statement. There are too many variables in that scenario.


Don't know if you are serious, whatever current can move through that screwdriver WILL. Everything the grid can push before the overcurrent opens will go across that screwdriver. Ever see them arc flash videos? That energy can be thousands or tens of thousands of amps. Overcurrent devices do not usually work instantly, they require a certain amount of time compared to the current drawn. Look up Time Current curves and be scared about the energy flowing through a 20a QO during a short. So when it trips, it is meeting these thresholds. Pretty scary stuff.


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## alselec53 (Jan 4, 2012)

*120/208v digging deeper.*



hardworkingstiff said:


> The 208 high leg is part of a 240V 3-phase Delta distribution system with a center tap between the other 2 legs (not the 208 leg). Here you are reading phase conductor to neutral and you really should not use this leg in conjunction with the neutral.
> 
> The other 208V you speak of is between 2 ungrounded conductors of a Wye distribution system, and you have 120V to neutral from either conductor.


Yes, good info, and I did come across a home, (not commercial) with 3ph 240v between legs and 120v to grd on 2 of them, and 208v on 1 of them. Looks to be put in, in the 50's. Whats to stop an unelectrician to tie in a ckt to that 208v to grd leg, thinking its 120v, to a regular plug.

That being said, what is the 208v for on the last (blue) leg for?
He had a 3ph A/C and a single ph 240v 100a sub panel fed from this panel. feeding the rest of the home ckts. Weird set up.

Also, all that being said.. Still not sure what the slightly less 208v is for in commercial bldgs? Whether its 3ph 208v between legs and 120v to grd? or 3ph 240v between legs, 120v to grd on 2 legs and 208v to grd on 1 leg.
Besides how its done in the Delta or Y transformers.. Why 208v to start with? and why the 208v (wild leg) on the other set up?


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## Surge03 (Sep 23, 2012)

480sparky said:


> Again... it's phase angles. It's a function of electrical math.
> 
> Since 120/208 is three-phase, the phases are 120° apart. If they were 180° apart (like a 120/240 single phase system). then it would be 120/240 3/phase. But since they're 120° apart, the voltage is 240 * sin(120).


And 3 phase is more efficient than than single phase


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## alselec53 (Jan 4, 2012)

*120/208v digging deeper.*



Surge03 said:


> And 3 phase is more efficient than than single phase


I understand the different phase angles changes things. It is intentially set up that way.. I'm asking why the slightly less voltage (208v) that is used in commercial between legs, and why the 208v (wild leg) on the other trans config?

Anotherwords, why not just keep everything 240v (single or 3 phase) in residential and commercial, (except for some voltages for specific applications). And not including 277/480v, we know why the higher voltage there.


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## FlatRateGator (Feb 13, 2013)

alselec53 said:


> Also, all that being said.. Still not sure what the slightly less 208v is for in commercial bldgs? Whether its 3ph 208v between legs and 120v to grd? or 3ph 240v between legs, 120v to grd on 2 legs and 208v to grd on 1 leg.
> Besides how its done in the Delta or Y transformers.. Why 208v to start with? and why the 208v (wild leg) on the other set up?


See my response in post #30. 208 arises BECAUSE we chose 120 V as our base voltage. We chose 120 because that became the standard for incandescent lighting in the early 20th Century.

So list the things we want in an electrical system:

1) Must be able to supply 120 V single phase
2) Must also be able to supply 3 phase

Ok. IF we want a system that can supply BOTH 120 V and 3-phase, then we are FORCED to have a 3-phase voltage of 208. We don't have a choice. We can only choose one voltage (120 V), the other is set by the physical laws that govern electricity.

As for delta connected 120/240, the 208 wild leg is a by-product of how it works. The grounded neutral point is *1/2 winding* away from two of the phases, so it has 120 V between those phases and ground. BUT the remaining phase is *1.5 windings* away from neutral, so the voltage between that phase and ground is higher by 1.732 times. It is that quirk of vector algebra that multiplies the voltage by the squareroot of 3. The highleg in a 120/240 delta has no use. It is simply a side effect of how the neutral is connected.


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## FlatRateGator (Feb 13, 2013)

alselec53 said:


> Anotherwords, *why not just keep everything 240v* (single or 3 phase) in residential and commercial, (except for some voltages for specific applications). And not including 277/480v, we know why the higher voltage there.


Because we would have to throw away all of our 120 V stuff.


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## Fibes (Feb 18, 2010)

alselec53 said:


> I understand the different phase angles changes things. It is intentially set up that way.. I'm asking why the slightly less voltage (208v) that is used in commercial between legs, and why the 208v (wild leg) on the other trans config?


The 208 voltages are unavoidable in the particular configurations. but looking at single phase 120/240 verses a 120/208 "wye"

Go out in your yard, drive a stake, call it XO, now walk in one direction 120 paces and drive another stake, call it A. Go back to XO and walk 120 paces @ 180 degrees in the opposite direction and drive a stake, call it B. Now walk from B to A and you have 240 paces. the legs or phases are 180 degrees from each other.

Now lets look at the angles of the "wye" .


Go out in your yard, drive a stake, call it B, now walk in one direction 120 paces and drive another stake, call it XO. Now instead of 180 degrees you are going to head off at 120 degress from where you walked to B and walk 120 paces and drive a stake called B. Now walk from B to A and you have 208 paces.

This shows the relationship of 208 voltage when the 120 volt windings are 
at 120 degree angles. This can not be helped


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## Shockdoc (Mar 4, 2010)

FlatRateGator said:


> See my response in post #30. 208 arises BECAUSE we chose 120 V as our base voltage. We chose 120 because that became the standard for incandescent lighting in the early 20th Century.
> 
> So list the things we want in an electrical system:
> 
> ...


It was actually 110 volts in the early days, rose to 115 and is now at 120.


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## FlatRateGator (Feb 13, 2013)

Shockdoc said:


> It was actually 110 volts in the early days, rose to 115 and is now at 120.


Yeah, but I didn't want to add any more confusion. 120 is close enough:laughing:


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## BBQ (Nov 16, 2010)

220/221 said:


> Now, what condition(s) would cause a short of over 10,000 amps?





480sparky said:


> A handyman dropping his screwdriver onto the busses bars.





220/221 said:


> Come on now. I'm not that bright but even *I* know that is not a true statement. There are too many variables in that scenario.


Of course they are variables but it is very possible to reach 10,000 amps even much higher levels at the bus bars of a panel.

The current rise is instant, the over-current device is not.


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## John (Jan 22, 2007)

Fibes said:


> The 208 voltages are unavoidable in the particular configurations. but looking at single phase 120/240 verses a 120/208 "wye"
> 
> Go out in your yard, drive a stake, call it XO, now walk in one direction 120 paces and drive another stake, call it A. Go back to XO and walk 120 paces @ 180 degrees in the opposite direction and drive a stake, call it B. Now walk from B to A and you have 240 paces. the legs or phases are 180 degrees from each other.
> 
> ...


This has been asked before and this is the thread......

http://www.electriciantalk.com/f2/newbies-friends-question-week-903/


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## Big John (May 23, 2010)

BBQ said:


> ...The current rise is instant, the over-current device is not.


 Exactly.

The number on the breaker handle just means it will never trip at _less_ than that value. It's very possible to go way, way, _way_ above the value for brief periods of time.


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## 480sparky (Sep 20, 2007)

Big John said:


> ........It's very possible to go way, way, _way_ above the value for brief periods of time.


And when it does, any video of the event usually goes viral.


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## Meadow (Jan 14, 2011)

If everything was the correct voltage at 240/415Y everything would be easier. But its not:laughing:


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## micromind (Aug 11, 2007)

BBQ said:


> Of course they are variables but it is very possible to reach 10,000 amps even much higher levels at the bus bars of a panel.
> 
> The current rise is instant, the over-current device is not.


Commercial/industrial; yes, residential; very rare. 

But any arcing fault in any panel is a serious hazard.


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## micromind (Aug 11, 2007)

meadow said:


> If everything was the correct voltage at 240/415Y everything would be easier. But its not:laughing:


I agree completely. 

I don't think much of the IEC garbage we get form overseas, but their power system is WAY better than ours.

All POCO transformers are 240. Single phase is two wires, not 3. 

3 transformers connected ∆ is 240 phase to phase. No high leg. 

3 transformers connected wye is 240 phase to neutral, and 415 phase to phase. 

Their motors are dual voltage, 6 lead. 240/415. Any motor works on either system. No 230 volt motors run on 208. 

All single phase loads are 240. This voltage is always available regardless of the service voltage. No transformers downstream of the service entrance. Just imagine the power wasted on all those 480 - 120/208 (or 240) transformers sitting there humming away, most of them loaded to less that 30% of their rating.


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## brian john (Mar 11, 2007)

erics37 said:


> A picture is worth a thousand words.
> 
> 
> 
> ...


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## erics37 (May 7, 2009)

brian john said:


> If you take a wye with the 3-120 VAC phase and draw a line between them so you have 3 triangles with a 120 Degree angle, two adjacent legs 120 VAC (inches, CMs or whatever) and tw0 30 degree angles, the tangent of the 120 degree angle is 1.732, the tangent times any one adjacent side will give you the lenght of the 3rd side 208 VAC (inches, CMs or whatever)


Congratulations, you just completely obfuscated what would otherwise be a nice, simple exercise in vector mathematics :laughing:


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## Meadow (Jan 14, 2011)

micromind said:


> I agree completely.
> 
> I don't think much of the IEC garbage we get form overseas, but their power system is WAY better than ours.
> 
> ...


Its not uncommon for parts of europe to have 3 phase power at new residentials. Along with no AFCI requirments either:thumbup:


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## Magnettica (Jan 23, 2007)

alselec53 said:


> Been in the trade for years and always wondered why they use 120/208v in commercial and 120/240 in residential. Plus with different transformers y, delta, 3 ph you have 120v to ground on 2 of the phases and 208v to grd on the last phase. Why the 120/208v, and why the wild led? in commercial?



They use 120/ 207V three-phase power for a lot of commercial/ industrial lots because motors run the most efficiently on 3-phase voltages. Things like rooftop unit furnaces, pumps, and condensing units. Plus with this configuration the grounded neutral in a wye system can be used to service your ordinary 120 volt loads like lighting and receptacles. Larger buildings receive higher voltage services like 480/277V for bigger machines and lighting that can be connected to 277V loads. Buildings like this also contain transformers to achieve the correct voltage, like 120/ 240 single phase. RxI=E, P/E = I. :thumbsup:


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## alselec53 (Jan 4, 2012)

*120/208v digging deeper.*

Ok, starting to make sense, its not that they need the 208v.. its that, thats what works out physically, in the Transformer config, when they set it all up to get the single and 3 phase configurations.


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## BBQ (Nov 16, 2010)

micromind said:


> Commercial/industrial; yes, residential; very rare.
> 
> But any arcing fault in any panel is a serious hazard.


We have many areas around me that use networks to supply homes and the fault current can be very high.


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## Magnettica (Jan 23, 2007)

alselec53 said:


> Ok, starting to make sense, its not that they need the 208v.. its that, thats what works out physically, in the Transformer config, when they set it all up to get the single and 3 phase configurations.



Basically, there are (3) phases of power that each measure 120 volts to the grounded "neutral" leg. These phases measured phase-to-phase are 208 volts. Only Wye transformer configurations contain the grounded neutral leg. Common voltages are 120/ 208 and 480/ 277.


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## alselec53 (Jan 4, 2012)

220/221 said:


> That is simple mechanical stuff that I learned when I was 12 but, yeah. The guy cutting my lawn doesn't really need to know the mechanics. He only needs to know to put oil/gas in the 2 stroke. :thumbsup:
> 
> 
> 
> Come on now. I'm not that bright but even *I* know that is not a true statement. There are too many variables in that scenario.


220-221 - you make some good points, and you are honest. But I tend to at least kinda try to understand how something works, (helps with troubleshooting etc.), buts that's ok, and, I don't know it all either, that's for sure. 

Like your ID - 220-221, "Mr Mom" was one of the funniest movies. :thumbup:


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## micromind (Aug 11, 2007)

BBQ said:


> We have many areas around me that use networks to supply homes and the fault current can be very high.


Two or more transformers in parallel that feed the lines that supply the houses?

I've seen that only a couple of times. Pretty rare around here. 

The most blatant one I've ever seen is in Austin Nevada. A small town in the mountains, maybe a couple of hundred people. The highway that runs through town has all 4 primary lines, and a single phase transformer on just about every pole. All paralleled together. 

There are 4 secondary lines that are fed from all these transformers, every couple of poles has two pots connected open delta. Actually, if you count all of them, it's a closed delta; eventually all 3 primary lines are used. 

When I saw that I wondered what the available fault current would be......


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## Meadow (Jan 14, 2011)

micromind said:


> Two or more transformers in parallel that feed the lines that supply the houses?
> 
> I've seen that only a couple of times. Pretty rare around here.
> 
> ...


Whats the drop guage to the house and how long? Some pocos will purposefully use thin drops to limit fault current.

@BBQ, where are these networks? Most NewEngland pocos like N-star, CL&P, National Grid ect dont parellel their transformers (overhead or pad-mount)

Con-ed in the 5 boroughs is the exception where everthing tends to be networked.


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## micromind (Aug 11, 2007)

meadow said:


> Whats the drop guage to the house and how long? Some pocos will purposefully use thin drops to limit fault current.
> 
> @BBQ, where are these networks? Most NewEngland pocos like N-star, CL&P, National Grid ect dont parellel their transformers (overhead or pad-mount)
> 
> Con-ed in the 5 boroughs is the exception where everthing tends to be networked.


Most of them looked pretty typical POCO small. Maybe #4 or #2 AL. 

One commercial building looked like maybe a 2/0. It was one of the 3ø drops.


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## Meadow (Jan 14, 2011)

micromind said:


> Most of them looked pretty typical POCO small. Maybe #4 or #2 AL.
> 
> One commercial building looked like maybe a 2/0. It was one of the 3ø drops.


They probably have an AIC requirment then. Dunno nor why they would parrallel them like that.


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## frenchelectrican (Mar 15, 2007)

meadow said:


> Its not uncommon for parts of europe to have 3 phase power at new residentials. Along with no AFCI requirments either:thumbup:


Most of the resdentail in UK side typically use more on single phase side than what we do over here in France.

But the key issuse is the service size limitation on single phase most of them useally cut off either 80 or 120 amp service size on single phase but if need bigger service then they will have no choice but go with triphase.

No AFCI requirement yet but heard there were some talking going on but I doubt it will ever use yet due we have pretty good set up with our main RCD / branch RCD's 

Merci,
Marc


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## Meadow (Jan 14, 2011)

frenchelectrican said:


> Most of the resdentail in UK side typically use more on single phase side than what we do over here in France.
> 
> But the key issuse is the service size limitation on single phase most of them useally cut off either 80 or 120 amp service size on single phase but if need bigger service then they will have no choice but go with triphase.
> 
> ...


Is it true that home ovens can be wired for both 3 phase or single phase in Europe?


BTW, Would you happen to have any pics of residential power systems in France like the consumer units or anything interesting?


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## frenchelectrican (Mar 15, 2007)

meadow said:


> Is it true that home ovens can be wired for both 3 phase or single phase in Europe?
> 
> 
> Oui., It can be wired either single phase or triphase but a nice gotcha is that with our French Nomes ( French codes ) anytime you use the three phase it have to be hardwired plus it have to use the local disconnecting switch. The single phase verison can go either way use the same methold as you guys done in state side either plug or use local disconnect switch ( all it depending on which area you are dealing )
> ...


I will dig up some photos to see what I can come up and I know we did have one guy from France as well he did have the photos what the typical French panels are.

So give me a little bit of time I will post it for ya.

Merci,
Marc


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## Meadow (Jan 14, 2011)

frenchelectrican said:


> I will dig up some photos to see what I can come up and I know we did have one guy from France as well he did have the photos what the typical French panels are.
> 
> So give me a little bit of time I will post it for ya.
> 
> ...


Thanks, really appreciate it!:thumbsup:


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## frenchelectrican (Mar 15, 2007)

meadow said:


> Is it true that home ovens can be wired for both 3 phase or single phase in Europe?
> 
> 
> BTW, Would you happen to have any pics of residential power systems in France like the consumer units or anything interesting?


Let me paste couple of them from website for a moment so that will give you a genral idea.



















Note both photos show monophase verison so triphase verison will be simauir to it.

I try to post the triphase verison some how the photo got too big so I will look to readjust the sizing in little bit.

Merci,
Marc

P.S.

I will post what is the typical small French service useage


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## erics37 (May 7, 2009)

frenchelectrican said:


>


Cool picture. Does the "40A-30mA" mean it's a 40 amp RCD with a trip level of 30 milliamps? I take it that's a pretty typical setup for a service in France. What is the operating voltage L-N? How many of those main breakers could you put into one panel?

And does that earth conductor system get bonded to anything like it does here in the US? I guess it wouldn't necessarily need to if everything ran through those RCDs, but even then 30 mA is a bit high if you had a high impedance ground fault path back to the utility source.


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## frenchelectrican (Mar 15, 2007)

erics37 said:


> Cool picture. Does the "40A-30mA" mean it's a 40 amp RCD with a trip level of 30 milliamps? I take it that's a pretty typical setup for a service in France. What is the operating voltage L-N? How many of those main breakers could you put into one panel?
> 
> And does that earth conductor system get bonded to anything like it does here in the US?


 
To answer your first question ., Oui it is 40 amp RCD with 30 ma tripping level and there is other verison have higher senstive level which it is at 10 ma setting that useally resvered for bathroom and pool / spa location.

The common single phase voltage is 240 volts line to netural.

Those " main " breaker the smaller panel it can go up to 3 mains but larger panels we can go many as 10 ( no merde on this one :blink: ) but more common to use larger RCD breaker in there instead of bunch of submains breakers.

The number of branch circuit breakers can really varies a bit depending on which type of panel and the biggest one I done some time back for redentail is 82 breakers! that for 7400 sq feet mansison house that worth over 5 mil Euros ! 

As far for earthing we can go either way but most case we do simair to what ya state guys done so far beside the few country area we do run in insolatated mode.

The most common mode useally is useally TN-S or TC-N-S depending on network and area it being used.

Merci,
Marc


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## Meadow (Jan 14, 2011)

frenchelectrican said:


> Let me paste couple of them from website for a moment so that will give you a genral idea.
> 
> 
> 
> ...


:thumbup:

Since these panels appear to not have a buss bar does that mean more than 1 wire can be put on a breaker screw? (jumper wires to act as the buss bar)

On a side note, I always thought having an RCD for all those circuits is silly. If one circuit has a ground fault, then you loose all 5 of them. Can each circuit have its own RCD breaker instead of a main RCD for all of them?


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## frenchelectrican (Mar 15, 2007)

meadow said:


> :thumbup:
> 
> Since these panels appear to not have a buss bar does that mean more than 1 wire can be put on a breaker screw? (jumper wires to act as the buss bar)
> 
> On a side note, I always thought having an RCD for all those circuits is silly. If one circuit has a ground fault, then you loose all 5 of them. Can each circuit have its own RCD breaker instead of a main RCD for all of them?


With the photo I posted they useally don't show the jumper bussbar but we do have them and they will come in few differnt rating depending on which type of jumper bussbar it used.

As far what we useally do is sub divived them so any one of them tripped due something trip the main RCD you will not leave the house in dark at all.

The other factor is the cost as well a 40 amp 30ma main RCD breaker useally run 30 Euros while a single pole 20 amp RCD breaker useally hit about 15 sometime 20 Euros depending on what brand I use on the panel.

And I am pretty sure you noticed that the line conductor and netural go thru each breaker there is for a good reason when the breaker trip it will isolated the netural as well for safety mesurement ( this part do come handy with crossed circuit or three phase useage ) 

For service size if you want to go larger one we can swap to larger panel just like you guys done in North Americian side that is not a issue but it can be pain in butt with underground runs with SWA cables ( good for cussing if not done right ) and we can add sections to increase to larger panel size.

For instering tibbits for ya we do have T&E cables the same as your NM cables we do slide the T&E cables behind the panel and go thur the KO's as well other type of cable is done simair but stopped at the panel houseing.

I know some of you will ask me for that small a service can we get them in triphase as well the answer is oui due we have sub mains so that help a bit.

Merci,
Marc


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## BBQ (Nov 16, 2010)

micromind said:


> Two or more transformers in parallel that feed the lines that supply the houses?


Yes, kind of common in Boston and Cambridge.


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## BBQ (Nov 16, 2010)

meadow said:


> @BBQ, where are these networks? Most NewEngland pocos like N-star, CL&P, National Grid ect dont parellel their transformers (overhead or pad-mount)


Maybe they don't know but they sure did and they are still in use.


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## frenchelectrican (Mar 15, 2007)

micromind said:


> Two or more transformers in parallel that feed the lines that supply the houses?


 
Even in few location in Wisconsin and in France have done the same way with either single phase or three phase with paralled transfomers.

The single phase are not too bad to get them in sych. but three phase there are couple extra step you have to take it to order it get working properly is polairty setting.

Merci,
Marc


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## Meadow (Jan 14, 2011)

BBQ said:


> Maybe they don't know but they sure did and they are still in use.



They do in Boston, Brockton, Springfield, Worcester, Providence, Fall River MA, Hartford, New Haven and in the center of Meriden CT, but those underground networks are only a very small portion of the regular service territory they cover. Most of the houses fed by those had no special requirements for AIC unless commercial. Could be wrong if I missed something though.


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## BBQ (Nov 16, 2010)

meadow said:


> They do in Boston, Brockton, Springfield, Worcester, Providence, Fall River MA, Hartford, New Haven and in the center of Meriden CT, but those underground networks are only a very small portion of the regular service territory they cover. Most of the houses fed by those had no special requirements for AIC unless commercial. Could be wrong if I missed something though.


:blink:

You had said they don't use them, then you list a bunch of places they do use them. Call me confused.:jester:

When we were doing condos in the 80s we often had to use service equipment with AIC ratings above 10kA.


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## Meadow (Jan 14, 2011)

BBQ said:


> :blink:
> 
> You had said they don't use them, then you list a bunch of places they do use them. Call me confused.:jester:
> 
> When we were doing condos in the 80s we often had to use service equipment with AIC ratings above 10kA.


They dont parellel (CL&P and National Grid anyways) when dealing with overhead cans and pad-mounted transformers. 

When dealing with underground vaults the norm is to parallel. Not that this has to do anything with AIC but the vault transformers have network protectors that open up on reverse power flows.


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## Meadow (Jan 14, 2011)

BBQ said:


> :blink:
> 
> When we were doing condos in the 80s we often had to use service equipment with AIC ratings above 10kA.


Not saying your wrong, your right, But often the branch breakers are 10ka rated. Never understood the whole series rating concept.


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## Meadow (Jan 14, 2011)

frenchelectrican said:


> With the photo I posted they useally don't show the jumper bussbar but we do have them and they will come in few differnt rating depending on which type of jumper bussbar it used.
> 
> As far what we useally do is sub divived them so any one of them tripped due something trip the main RCD you will not leave the house in dark at all.
> 
> ...


Is it true that they use NM type cable everywhere? ie, where we find MC and conduit here in commercial they go for "T&E" cables.


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## BBQ (Nov 16, 2010)

meadow said:


> Not saying your wrong, your right, But often the branch breakers are 10ka rated. Never understood the whole series rating concept.


Correct, we would have a fused main disconnect with a high rating and standard breakers on the branch circuits.

But to go back to what started this, if like Ken said someone dropped a screwdriver across the bus you could have more than 10,000 amps of current.


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## BBQ (Nov 16, 2010)

I think the main point was trying to make 220/221 understand that far higher current can pass through an overcurrent device than its marked rating before it opens.


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## frenchelectrican (Mar 15, 2007)

meadow said:


> Is it true that they use NM type cable everywhere? ie, where we find MC and conduit here in commercial they go for "T&E" cables.


Not everywhere we can use the T&E cable at all we have simauir rules as you guys have so we use MC or in conduit useally either EMT or PVC ( more common )

Merci,
Marc


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## frenchelectrican (Mar 15, 2007)

BBQ said:


> Correct, we would have a fused main disconnect with a high rating and standard breakers on the branch circuits.
> 
> But to go back to what started this, if like Ken said someone dropped a screwdriver across the bus you could have more than 10,000 amps of current.


That true and if the transfomer have pretty high supply rating the chance of haveing pretty high current.

Hey BBQ., Did you recall there were a thread related to this subject some time back either in this fourm or other fourm ? 

I know there were couple of them but I just can't really recall which one have the best answer on that.

Merci,
Marc


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## BBQ (Nov 16, 2010)

I can't think of one right now. I am sure there are just cant remember them.


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## Meadow (Jan 14, 2011)

BBQ said:


> Correct, we would have a fused main disconnect with a high rating and standard breakers on the branch circuits.
> 
> But to go back to what started this, if like Ken said someone dropped a screwdriver across the bus you could have more than 10,000 amps of current.


But thats what Ive never been able to understand, if you need a high AIC main and you can get over 10ka of fault current on the buss, then why can the branch breakers be rated 10ka? Shouldn't they be rated the same as the main.,


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## frenchelectrican (Mar 15, 2007)

Fair engough I am pretty sure something will popped up in the mind when it do comes.,

While we are on simauir subject ., Not too long ago I got a letter from EDF did mention about the AIC rating due some of the system been upgrading with better system and few area I will end up replace with better breaker with higher AIC rating.

So that something I know it will show up one way or other.

Merci,
Marc


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## BBQ (Nov 16, 2010)

meadow said:


> But thats what Ive never been able to understand, if you need a high AIC main and you can get over 10ka of fault current on the buss, then why can the branch breakers be rated 10ka? Shouldn't they be rated the same as the main.,


I am with you there, I don't know how series ratings work either.


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## Meadow (Jan 14, 2011)

frenchelectrican said:


> Not everywhere we can use the T&E cable at all we have simauir rules as you guys have so we use MC or in conduit useally either EMT or PVC ( more common )
> 
> Merci,
> Marc


Got it! 

Is this the T&E cable you were speaking of?


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## frenchelectrican (Mar 15, 2007)

meadow said:


> But thats what Ive never been able to understand, if you need a high AIC main and you can get over 10ka of fault current on the buss, then why can the branch breakers be rated 10ka? Shouldn't they be rated the same as the main.,


There are few ways it can be done in series rating if you used the correct breakers as the breaker manufacter post the listing what it can be use with the other combation to get that rating of higher AIC.

Most case in resdentail panels which I know in state side they useally are 10K AIC for branch but for the main the old days it used to be 10 K but now they are getting dual rated 10/22K due some of the system is getting larger or very close to the transfomer.

I know the SqD and couple other manufacters did have pretty good details on the AIC rating and I will try to find one ( Hope my bookmarker do work on this one )

Merci.
Marc


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## frenchelectrican (Mar 15, 2007)

meadow said:


> Got it!
> 
> Is this the T&E cable you were speaking of?


Oui, they do come few differnt size as well.

Merci,
Marc


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## frenchelectrican (Mar 15, 2007)

BBQ said:


> I am with you there, I don't know how series ratings work either.


 
It took me a while to figure it out but right now I will post the details as soon I get good link to posted in here so that way other members can understand in plain nutshell.

I did found one but right now looking for a engish verison so give me a bit of time to find it.

Merci,
Marc


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## erics37 (May 7, 2009)

BBQ said:


> I am with you there, I don't know how series ratings work either.


I think this is part of the answer:



frenchelectrican said:


> *There are few ways it can be done in series rating if you used the correct breakers as the breaker manufacter post the listing what it can be use with the other combation to get that rating of higher AIC.*


In my apprentice class we had a GE rep come through to give us a sales pitch, I MEAN to explain some of the basics regarding AIC and selective coordination and all that. He produced some literature that included basically a big table of all the combinations of every GE circuit breaker they made and what the series rating of all those combinations was.

So somehow or another, different ratings of breakers can work in conjunction with one another to allow for different scenarios. I don't know how the math or science works, but I think that's the gist of it.


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## hardworkingstiff (Jan 22, 2007)

I have no training or education on series rating, but this is my understanding (right or wrong).

The breakers that are listed to work with each other have been tested and documented to work with each other. The principle is that the higher rated breaker will open soon enough under a fault condition that the lower rated breaker will not be damaged. 

Example: You have a 22kaic rated 800-amp main and a 10kaic 200-amp branch breaker. Down stream of the 200-amp breaker a fault occurs generating 15,000 amps of fault current. Both breakers will attempt to open and although the 200-amp may not be able to interrupt the fault current, the 800-amp will and it does so soon enough that the 200-amp breaker is not damaged.

I have a suspicion that a lot of series rated systems would work fine, but we are only allowed to use the ones that are listed that way.

I await an educated person to confirm or correct my understanding.


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## frenchelectrican (Mar 15, 2007)

Kinda bring this update a little where we left off about the AIC rating so I will post a link this may help ya but it kinda little long winded but have few good charts in there.

http://www.eaton.com/ecm/groups/public/@pub/@electrical/documents/content/1143077774657.pdf

I am sure there are other manufacter may list more details with their products so the one I posted is for Eaton products so the Sq D or GE or others will advise to check with their manufacer for listing.

The only thing I havent check is cross manufacter listing so this part is kinda hard to say what the result will be.

Merci,
Marc


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## FlatRateGator (Feb 13, 2013)

meadow said:


> But thats what Ive never been able to understand, if you need a high AIC main and you can get over 10ka of fault current on the buss, then why can the branch breakers be rated 10ka? Shouldn't they be rated the same as the main.,


No, because each OCPD and feeder introduces enough impedance to reduce the fault current quite a bit. Get the Mike Holt fault spreadsheet and play with the feeder lengths etc. to see how the fault current varies.


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## Meadow (Jan 14, 2011)

FlatRateGator said:


> No, because each OCPD and feeder introduces enough impedance to reduce the fault current quite a bit. Get the Mike Holt fault spreadsheet and play with the feeder lengths etc. to see how the fault current varies.


 

Do you have the MH link?


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## FlatRateGator (Feb 13, 2013)

meadow said:


> Do you have the MH link?


http://mikeholt.com/freestuff.php?id=freegeneral


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## Meadow (Jan 14, 2011)

frenchelectrican said:


> Kinda bring this update a little where we left off about the AIC rating so I will post a link this may help ya but it kinda little long winded but have few good charts in there.
> 
> http://www.eaton.com/ecm/groups/public/@pub/@electrical/documents/content/1143077774657.pdf
> 
> ...


Thanks for the link.

I found some consumer unit pics on my computer saved from Google a while back.

The first one I think is French the second one might be Britsh? The last one looks like its not up to code I guess.


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## frenchelectrican (Mar 15, 2007)

meadow said:


> Thanks for the link.
> 
> I found some consumer unit pics on my computer saved from Google a while back.
> 
> The first one I think is French the second one might be Britsh? The last one looks like its not up to code I guess.


Pas de probem .,

The first photo is correct is that is French style panelboard.

The second ya got it correct that is British panel set up and it have two voliations I can spot right off the wall the first one is wrong OCPD sizeing unless that is used for A/C unit we have some leeway pretty simauir to your art 430/440's 

Second voilations is not properly marked main tails ( main cables ) 

Btw we don't use 100 amp breaker in France very often in resdentail useage but industrial purpose ., yeah semi common.

Merci,
Marc


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## Meadow (Jan 14, 2011)

frenchelectrican said:


> Pas de probem .,
> 
> The first photo is correct is that is French style panelboard.
> 
> ...


Is this by chance a TT or maby even IT earthed system because I see no ground wire with the main wires in the British panel?


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## frenchelectrican (Mar 15, 2007)

meadow said:


> Is this by chance a TT or maby even IT earthed system because I see no ground wire with the main wires in the British panel?


More likey TT format I know British used to do that alot but seems they are dropping out of that one for floating ground issue so with the TT earthing format it must have RCD on it if not., it is not any better than North Americian TT format at all.

Oh by the way it is illegal for us ( In France ) to use the TT format for last 15 years too many issue with RCD not working properly with TT system.

Merci,
Marc


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## Meadow (Jan 14, 2011)

frenchelectrican said:


> More likey TT format I know British used to do that alot but seems they are dropping out of that one for floating ground issue so with the TT earthing format it must have RCD on it if not., it is not any better than North Americian TT format at all.
> 
> Oh by the way it is illegal for us ( In France ) to use the TT format for last 15 years too many issue with RCD not working properly with TT system.
> 
> ...


One more question, an Engineer told me that in Norway there system is IT and Delta, how does that work there?


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## frenchelectrican (Mar 15, 2007)

meadow said:


> One more question, an Engineer told me that in Norway there system is IT and Delta, how does that work there?


 
The IT system is used on older homes in Norway and they are no longer used they did switch over to TN-C-S system due it is much safer.

I will post a summary of the IT system ( I did transalted from French to Engish for ya ) 


In IT systems, a single insulation fault is unlikely to cause dangerous currents to flow through a human body in contact with earth, because no low-impedance circuit exists for such a current to flow. However, a first insulation fault can effectively turn an IT system into a TN system, and then a second insulation fault can lead to dangerous body currents. Worse, in a multi-phase system, if one of the live conductors made contact with earth, it would cause the other phase cores to rise to the phase-phase voltage relative to earth rather than the phase-neutral voltage. IT systems also experience larger transient overvoltages than other systems.

Now you can see why it did change for safety issue.

Sure they did use old delta floating sytem but not in true three wire sans ground format they did use 4 wire which the 4 th one is earthing ( ground ) conductor and that part is allready dropping out to more modern wye system. 

Hope that clear up that question if not let me know.

Merci,
Marc


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## Meadow (Jan 14, 2011)

frenchelectrican said:


> The IT system is used on older homes in Norway and they are no longer used they did switch over to TN-C-S system due it is much safer.
> 
> I will post a summary of the IT system ( I did transalted from French to Engish for ya )
> 
> ...


Ok its making more sence now. So there was a 3rd (or fourth wire) run along the poles and to the houses that was for grounding but is now being used as neutral like here in north America.

What type of circuit breakers did they use for this system, were they RCD or did they resemble what you see in older north american factorys with a 3 wire delta services with all 2 pole and 3 pole breakers?


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## frenchelectrican (Mar 15, 2007)

meadow said:


> Ok its making more sence now. So there was a 3rd (or fourth wire) run along the poles and to the houses that was for grounding but is now being used as neutral like here in north America.
> 
> Oui ., Ya got it now.
> 
> What type of circuit breakers did they use for this system, were they RCD or did they resemble what you see in older north american factorys with a 3 wire delta services with all 2 pole and 3 pole breakers?


Belive or not in old days we used the Daized fuse and when they switch over to the circuit breakers they were single pole verison for single phase verison ( few do use two pole but did NOT switch netural that time ) and standard three phase breakers for whole house protecton or branch circuit.

And yeah there were look simair to old North Americian factory with delta system in there but only smaller in sizewise.

And the RCD did not show up until mid 70's sorta simair time line with your GFCI's devices.

Now with modern regulations the fuse is not much used beside the special appatication beside the industrial users.

I will post the photo what daized fuse look like. there is pretty wide varations of size and shape we can use.











So that will help ya again.

Merci,
Marc


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## Meadow (Jan 14, 2011)

Wow, I can only imagine what would happen when only one fuse blew in a Norway system and the other did not. Talk about being live when appearing not to be.







I found some PDFs on line which I found interesting. Thought you might like them in case you havnt seen them.

http://www.schneider-electric.com/d...ility-safety/low-voltage-minus-1kv/ect172.pdf

http://www.schneider-electric.com/d...ility-safety/low-voltage-minus-1kv/ect173.pdf

http://www2.schneider-electric.com/documents/designers/top-downloads/090197c6800bcbde_.pdf

This one has pics of violations across Europe I think:

http://www.kontrollbuero.ch/fotogalerie/fotogalerie.htm


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## frenchelectrican (Mar 15, 2007)

meadow said:


> Wow, I can only imagine what would happen when only one fuse blew in a Norway system and the other did not. Talk about being live when appearing not to be.
> 
> Just trust me on this one I did got hit with that type of system before I got wise up quick after that I have to double check the voltage.
> 
> ...


 
Thanks for the link I have old edition and Merci for bring it up to date with new links so I did book mark them.

Now for the last link as you posted that is pretty much cover few area in European areas I think I did see they mention once maybe twice with Americiane system due that link was in German so took me few extra minuites to figure it out. 

But really between the North Americian and European side with code voliations there is no winner at all., We have to fix the cluster whatever mess espcally we have few unlicensed hacks running allover the mainland European area so techally wise it not any better than Americian or Canadian hacks are.

Merci,
Marc


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