# Solve This Service Call



## Toronto Sparky (Apr 12, 2009)

Looks like it went out on a short. Is it feeding a breaker panel? Often the main fuse will blow before a smaller breaker will on a short. How about Time Delay HRCs


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## te12co2w (Jun 3, 2007)

I don't know the aic rating of that fuse. Too close to the xmfr, and more fault current than the fuse is capable of handling?


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## 480sparky (Sep 20, 2007)

Toronto Sparky said:


> Looks like it went out on a short. Is it feeding a breaker panel? Often the main fuse will blow before a smaller breaker will. How about Time Delay HRCs


 
There's a 100a meter/main pedistal behind each unit along the property line that feeds a subpanel next to each unit. Each unit (typically) has a 50a cord on them, so the subpanels have two 50a 4-wire receps (same as a resi range does).

But this fuse was one of the two in the meter/main pedistal.




te12co2w said:


> I don't know the aic rating of that fuse. Too close to the xmfr, and more fault current than the fuse is capable of handling?


Each transformer feeds 4 meter/main pedistals, two on each side. I would guess the transformer is about 120' away from this pedistal.


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## Toronto Sparky (Apr 12, 2009)

A 100A onetime fuse will almost always blow before a 50A breaker on a dead short.
I would check out the cables feeding the trailers and the panels within the trailers.
Also I would think that if the main disconnect is before the meters they would have a seal on it.


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## 480sparky (Sep 20, 2007)

Toronto Sparky said:


> A 100A onetime fuse will almost always blow before a 50A breaker on a dead short.
> I would check out the cables feeding the trailers and the panels within the trailers.
> Also I would think that if the main disconnect is before the meters they would have a seal on it.


The meter/main pedistals are two-sides. There's a 100a meter socket on each side, each meter facing the unit they serve. Below each socket is the 100a pull-out fuses (this place was built in the 60s). From there, each feeder runs to a subpanel next to each unit where they plug in.

The only breakers I know of are either in the units themselves, or in the 6 or so units I've replaced the subpanels with new ones, but that isn't the case here. The subpanel is an original with two sets of 50a fuses.

(Most of them are older units with 50a cords, but some of the new ones are 100a and I direct wire them)


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## drsparky (Nov 13, 2008)

Was the other fuse a FRN-R current limiting fuse?


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## Larry Fine (Oct 24, 2007)

480sparky said:


> S
> 
> 
> 
> ...


Looking at the top blade, I'd say the fuse element is being overheated by a loose connection. I'd have to see the fuse clip to be more certain.

_Added:_ Unless they should have time-delay fuses to allow for the AC's inrush current. I believe the "NON" means non-time-delay.


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## 480sparky (Sep 20, 2007)

drsparky said:


> Was the other fuse a FRN-R current limiting fuse?


No. This is one of the two that were identical.



Larry Fine said:


> Looking at the top blade, I'd say the fuse element is being overheated by a loose connection. I'd have to see the fuse clip to be more certain.
> 
> _Added:_ Unless they should have time-delay fuses to allow for the AC's inrush current. I believe the "NON" means non-time-delay.


The pull-out seemed to have tight clips holding the fuses, but I couldn't get to the clips the pull-out pushes in to as they were shrouded and would require the meter to be removed to deenergize them. And of course, the POCO had one of those stupid huge barrel locks on it.


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## drsparky (Nov 13, 2008)

480sparky said:


> And of course, the POCO had one of those stupid huge barrel locks on it.


Want to by a barrel lock key? Only $1350, serious offers only!:whistling2:


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## drsparky (Nov 13, 2008)

I am not there so I give up, whats the answer?


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## Larry Fine (Oct 24, 2007)

drsparky said:


> I am not there so I give up, whats the answer?


I have the feeling he doesn't know and want's us to figure it out so he can get all the credit. :shuriken:


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## 480sparky (Sep 20, 2007)

Larry Fine said:


> I have the feeling he doesn't know and want's us to figure it out so he can get all the credit. :shuriken:


I know perfectly well what the answer is.

I'm just letting others read the thread so they can offer their opinions.



And there's no apostrophe in _want's._


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## B4T (Feb 10, 2009)

I got a feeling someone changed a switch for an outdoor light that is rarely used. :blink:


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## Larry Fine (Oct 24, 2007)

480sparky said:


> And there's no apostrophe in _want's._


I knew that. :whistling2:


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## Minuteman (Dec 29, 2007)

Okay Ken, there has to be more to the story. There is no way, by looking at a fuse, that i can tell what the problem is. Other than what Larry said about the top blade, nothing looks wrong with that fuse. 

So, if there is nothing wrong with the fuse, then it's either a intermittent short or an occasional over current.


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## ralpha494 (Oct 29, 2008)

Does the rain have something to do with it? Completing a circuit to ground? 

I noticed some of the residual anti-darkness at the top of the fuse, is a black hole forming?


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## captkirk (Nov 21, 2007)

YOUR KILLING me..............what is it....? And why would you show the fuse.......:001_huh:


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## drsparky (Nov 13, 2008)

The fuse was upside down and all the electrons fell out the vent hole.irate:


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## user4818 (Jan 15, 2009)

480sparky said:


> So, last night, just as I started cooking supper (
> 
> 
> 
> ...


What's the big deal? Mac and cheese and hot dogs don't take much effort to prepare.


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## 480sparky (Sep 20, 2007)

Minuteman said:


> Okay Ken, there has to be more to the story. There is no way, by looking at a fuse, that i can tell what the problem is. Other than what Larry said about the top blade, nothing looks wrong with that fuse.
> 
> So, if there is nothing wrong with the fuse, then it's either a intermittent short or an occasional over current.


This is the fuse that was blown. It was one of the original ones. The other had blown before, now this one.




ralpha494 said:


> Does the rain have something to do with it? Completing a circuit to ground?


Just commenting about how these types of service calls always seem to happen during inclement weather. 




Peter D said:


> What's the big deal? Mac and cheese and hot dogs don't take much effort to prepare.


Yea, but I was making mac n cheese with hot dogs.



I guess the purpose of this is to see where you guys would start looking for the problem. Test your own trouble-shooting skills in the comfort of your own home. And as a learning experience for those who want to pick up some trouble-shooting skill.

Sometimes, the trouble with trouble-shooting is you may not really find an obvious problem that can be solved. Yes, a bare ground wire touching a hot wire in a device box is pretty obvious, but sometimes you just need to go with a hunch based on experience.

This excercise is to see how quickly you come to the same conclusion I did. I won't reveal the final solution for a couple days..... not to torment you, but to give those who drop in once in a while a chance to participate.

If we find these drills useful, maybe we can post more of them.


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## Minuteman (Dec 29, 2007)

I see your point, and I enjoy a mystery. I'm just not sure that I have enough of the story. Got another clue?


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## 480sparky (Sep 20, 2007)

Minuteman said:


> ........Got another clue?


Depends. Do you think it's been solved already, or would you start looking for something else?


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## captkirk (Nov 21, 2007)

drsparky said:


> The fuse was upside down and all the electrons fell out the vent hole.irate:


 LOL nice, thats what I tell the customers


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## Minuteman (Dec 29, 2007)

480sparky said:


> Depends. Do you think it's been solved already, or would you start looking for something else?


Yep, you already said so. Remember?



480sparky said:


> I know perfectly well what the answer is.
> 
> I'm just letting others read the thread so they can offer their opinions.


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## 480sparky (Sep 20, 2007)

Minuteman said:


> Yep, you already said so. Remember?


OK, so I stated that wrong. 

Do you think of the solutions offered so far one is the 'correct' one, or do you think you need to look for something else as the cause?

I said _I_ know the solution (at least the one_ I_ think is 'correct'), let's see if the general consensus is the same.


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## Minuteman (Dec 29, 2007)

Let me guess. One of the Trailer Parkers was tampering with the pedestal, trying to get free power. (That's why there was a Watt Lock installed). The electric thief attached jumper cables improperly and blew the fuse.


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## 480sparky (Sep 20, 2007)

Minuteman said:


> Let me guess. One of the Trailer Parkers was tampering with the pedestal, trying to get free power. (That's why there was a Watt Lock installed). The electric thief attached jumper cables improperly and blew the fuse.


 
All the meters have the barrell locks on them.

Besides, in order to blow the fuse, they would have to hook on to the load side of the fuses.... no need to mess with the meter.


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## B4T (Feb 10, 2009)

480sparky said:


> I said _I_ know the solution (at least the one_ I_ think is 'correct'), let's see if the general consensus is the same.


So this is not a final answer question.. meaning you have not found a true cause yet?


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## RePhase277 (Feb 5, 2008)

Water is coming down service entrance and into meter. From there surface tension is causing it to run into one fuse?


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## ralpha494 (Oct 29, 2008)

The fuse doesn't have any signs of contact with water. It looks like white powder from a short circuit (not overload) on the top of the fuse. You said trailer park. Did they get a double wide in place of the old one? Trenching where the feed is? A bad A/C? I give up. 

Our first seminar in the fall is residential troubleshooting. I hope this turns into something we can use as an example.


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## John (Jan 22, 2007)

Underground feeder problem due to:
1. Dead woodchuck
2. Dead excavator operator
3. Dead backhoe operator
4. Aluminum oxide


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## 480sparky (Sep 20, 2007)

Black4Truck said:


> So this is not a final anawer question.. meaning you have not found a true cause yet?


I have. I'm using this as an exercise for you to see if you can 'find' it as well.


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## RePhase277 (Feb 5, 2008)

Wasn't this thread locked?


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## John (Jan 22, 2007)

John said:


> Underground feeder problem due to:
> 1. Dead woodchuck
> 2. Dead excavator operator
> 3. Dead backhoe operator
> 4. Aluminum oxide


5. A series of temporary overages can weaken the fuse's filament, which means the fuse will blow without exceeding the amperage rating. 

But I still think it is #2 the dead excavator operator...:whistling2:


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## John (Jan 22, 2007)

InPhase277 said:


> Wasn't this thread locked?


Yes it was but somebody resurrected it for some reason.


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## MDShunk (Jan 7, 2007)

InPhase277 said:


> Wasn't this thread locked?


Yeah, it was, because I hate threads like this. Somebody cried to the owner multiple times and now it's back on again. This thing better come to some point here pretty quick.


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## B4T (Feb 10, 2009)

InPhase277 said:


> Wasn't this thread locked?


I did not see a lock on this thread. There was no fighting, name calling, or potty mouth going on about the UNION :laughing: 

So why would a mod lock it? :blink:


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## MDShunk (Jan 7, 2007)

Black4Truck said:


> I did not see a lock on this thread. There was no fighting, name calling, or potty mouth going on about the UNION :laughing:
> 
> So why would a mod lock it? :blink:


My own pet-peeve. No particular rule broken. What's most interesting is that the crybaby went right to the owner and completely bypassed the mods.


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## B4T (Feb 10, 2009)

MDShunk said:


> My own pet-peeve. No particular rule broken. What's most interesting is that the crybaby went right to the owner and completely bypassed the mods.


In the past, I have always seen a mod post a reason for closing a thread.

That IMO just shows respect for the rest of us who posted on that thread.

A good example was yesterday when the "Welcome Larry" thread was closed. :thumbsup:


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## 76nemo (Aug 13, 2008)

MDShunk said:


> My own pet-peeve. No particular rule broken. What's most interesting is that the crybaby went right to the owner and completely bypassed the mods.


 
Easy now Killer


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## user4818 (Jan 15, 2009)

76nemo said:


> Easy now Killer


So you're the crybaby.


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## 76nemo (Aug 13, 2008)

Peter D said:


> So you're the crybaby.


 
You sure can be a smart aleck. I think you're a comedian, oh wait, I mean I think you think you're a comedian:thumbup:


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## MDShunk (Jan 7, 2007)

Black4Truck said:


> In the past, I have always seen a mod post a reason for closing a thread.
> 
> That IMO just shows respect for the rest of us who posted on that thread.
> 
> A good example was yesterday when the "Welcome Larry" thread was closed. :thumbsup:


I'm not always respectful. 

If the answer is still a mystery to anyone, read about NON fuses in this datasheet and plot some ordinary household cooling appliances on the trip curve:

http://www.google.com/url?sa=t&sour...+curve&usg=AFQjCNGxFDiLYuY2KXuvxKXQsfiLgu6vvg


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## John (Jan 22, 2007)

It is kind of annoying when very little information is given and the thread drags on and on and on...


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## Richard Rowe (May 25, 2009)

I assume the standard load on all the units is similar so it is not a simple overload. The first electrican said it was POCO problem so it would be somewhere around the meter maybe coming in from the transformer. Ok can we get a hot cold or warm on somebodys reply??? Just a hint!


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## John (Jan 22, 2007)

fuse Osteoporosis 

View attachment 1519


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## MDShunk (Jan 7, 2007)

A NON fuse probably worked fine for trailer homes when the park was built out. When people started adding window shakers or central air, a NON fuse won't really work. The trip curve is damn near a straight line.


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## steelersman (Mar 15, 2009)

Can this thread come to fruition already? I need to go to bed in a few. The world revolves around me.


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## 480sparky (Sep 20, 2007)

steelersman said:


> Can this thread come to fruition already? I need to go to bed in a few. The world revolves around me.


Well, Marc hit it right on the head.



MDShunk said:


> A NON fuse probably worked fine for trailer homes when the park was built out. When people started adding window shakers or central air, a NON fuse won't really work. The trip curve is damn near a straight line.


I was just trying to provide a real-life troubleshooting call to give the members a chance to solve a riddle. 

Not every regular member is online every night, so I thought I'd let it go for a while to give them a chance to participate in the exercise.

Are we now to assume if a question cannot be answered with "Yes/No: Article xxx.xx", it gets locked up?


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## John (Jan 22, 2007)

steelersman said:


> Can this thread come to fruition already? I need to go to bed in a few. The world revolves around me.


Go to bed. :thumbsup:
The OP is fishing for free info and the thread will go on until he gets enough suggestions in order to solve his problem.


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## 480sparky (Sep 20, 2007)

John said:


> Go to bed. :thumbsup:
> The OP is fishing for free info and the thread will go on until he gets enough suggestions in order to solve his problem.


 
OK, if you read the thread, you'll know this is the _*fourth time*_ I've said *I ALREADY KNOW THE SOLUTION: THIS IS SIMPLY AN EXERCISE FOR THE BENEFIT OF THE MEMBERS.*


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## John (Jan 22, 2007)

John said:


> 5. A series of temporary overages can weaken the fuse's filament, which means the fuse will blow without exceeding the amperage rating.
> :


I still think that old age had something to do with it blowing the fuse.


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## RePhase277 (Feb 5, 2008)

480sparky said:


> Are we now to assume if a question cannot be answered with "Yes/No: Article xxx.xx", it gets locked up?


Yes, yes we are.


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## 480sparky (Sep 20, 2007)

InPhase277 said:


> Yes, yes we are.


 
Yes. Article 90.1(C).:laughing:


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## John (Jan 22, 2007)

480sparky said:


> OK, if you read the thread, you'll know this is the _*fourth time*_ I've said *I ALREADY KNOW THE SOLUTION: THIS IS SIMPLY AN EXERCISE FOR THE BENEFIT OF THE MEMBERS.*


I read the thread and I don't see the benefit of 50+ posts and 2 days of guessing.


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## 480sparky (Sep 20, 2007)

John said:


> I read the thread and I don't see the benefit of 50+ posts and 2 days of guessing.


Would you rather bill a customer for 2 days of labor because you didn't know to look at the fuses?

Not everyone is in the service call sector of the trade. Some here work strictly in new installations and don't have the opportunity to do service call work.

Whenever I go on a service call, I look at it as a challenge. My assumption was there's a slice of members here who would relish the chance to do so, but their current assignments prevent them. All I tried to do is give them a chance to brush up on the skills unique to the troubleshooting facet of our trade.



I guess I was totally and absolutely wrong. I'll just shut up now.


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## steelersman (Mar 15, 2009)

FWIW, I can appreciate your effort and don't have a problem with your post, as long as I can PM you and you will give me the answer on future threads should there be any more.


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## drsparky (Nov 13, 2008)

So you solved it with FRN-R current limiting fuses.


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## RePhase277 (Feb 5, 2008)

drsparky said:


> So you solved it with FRN-R current limiting fuses.


If by "FRN-R" you mean "foil tape", and by "current limiting" you mean "conduit hammered flat at the ends", then yes, that is the solution.:thumbsup:


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## Toronto Sparky (Apr 12, 2009)

Toronto Sparky said:


> Looks like it went out on a short. Is it feeding a breaker panel? Often the main fuse will blow before a smaller breaker will on a short. How about Time Delay HRCs


This would also solve the problem. first answer.


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## Minuteman (Dec 29, 2007)

Minuteman said:


> Okay Ken, there has to be more to the story. There is no way, by looking at a fuse, that i can tell what the problem is. Other than what Larry said about the top blade, nothing looks wrong with that fuse.
> 
> So, if there is nothing wrong with the fuse, then it's either a intermittent short or an occasional over current.


Q. Why did the OCP device blow?

A. Overcurrent or short. 

:whistling2:


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## RePhase277 (Feb 5, 2008)

Minuteman said:


> Q. Why did the OCP device blow?
> 
> :whistling2:


'Cause it needed the money...OOHH!


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## Toronto Sparky (Apr 12, 2009)

Bloating shows short.


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## Larry Fine (Oct 24, 2007)

Black4Truck said:


> A good example was yesterday when the "Welcome Larry" thread was closed. :thumbsup:


Yeah, what's up with that?! :blink:










J/K


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## Larry Fine (Oct 24, 2007)

480sparky said:


> Well, Marc hit it right on the head.


As did I way back in post #8:



Larry Fine said:


> Unless they should have time-delay fuses to allow for the AC's inrush current. I believe the "NON" means non-time-delay.


Gotta get credit wherever I can.


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## wvwirenut (Apr 24, 2009)

As mentined earlier, not all of us are able to be online every night.

I missed the original pic that was posted. I would still like to see it if possible.


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## Fredman (Dec 2, 2008)

480sparky said:


> Would you rather bill a customer for 2 days of labor because you didn't know to look at the fuses?
> 
> Not everyone is in the service call sector of the trade. Some here work strictly in new installations and don't have the opportunity to do service call work.
> 
> ...


*HEY 480 ! *

*Count me in as appreciating the effort (and lesson). Thanks*


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## guschash (Jul 8, 2007)

Thanks 480 I agree with you on this thread, I enjoyed it. Md don't get so upset, we're hear to learn. I appreciate someone we your knowledge but some of us ( me ) are not as smart and threads like this help.


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## B4T (Feb 10, 2009)

wvwirenut said:


> As mentined earlier, not all of us are able to be online every night.
> 
> I missed the original pic that was posted. I would still like to see it if possible.


Look on page 1.. post #1


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## wvwirenut (Apr 24, 2009)

Black4Truck said:


> Look on page 1.. post #1


I've went all through the thread and don't see it. It may be my web browser, but I've always been able to see them before. Thanks.


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## user4818 (Jan 15, 2009)

76nemo said:


> You sure can be a smart aleck. I think you're a comedian, oh wait, I mean I think you think you're a comedian:thumbup:


No, I'm a comedian. A horrible one, but still a comedian nonetheless.


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## B4T (Feb 10, 2009)

Peter D said:


> No, I'm a comedian. A horrible one, but still a comedian nonetheless.


 
Maybe you can be the CARROT TOP of the electrical industry.

You could get a GREENLEE BOX and fill it with all kinds of stuff to plug into an outlet. :laughing:


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## vinster888 (May 3, 2009)

yeah like paper clips and keys. :laughing: oh wait with the tamper proof ones you need to bend your paper clip into a 'u' and use two keys. ooohhh twice the fun. :thumbup:


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## Minuteman (Dec 29, 2007)

My apologies to 480Sparky. I'm now very glad that he started this thread.

I got an emergency call today at a privet school cafeteria. One of those, "half the power is out" type. Two rows of lights were out. There are three 120v. reach in freezers, but one had no power.

The kitchen panel was okay, but nothing was marked. There was another panel in the hallway that had the light circuits marked, but hardly anything else. Sure enough, one phase was out. I went to the outside MDP and all phases were on and the 100-amp feeder breaker marked for "hall panel" was not tripped. Checked the breaker and had voltage. Asked a few questions, and found out that there was a number of fuse boxes located behind the gym.

There it was, a blown 100-amp NON fuse on one leg. (In an unmarked disconnect). *BANG* I remember 480Sparky and this thread. Ran down to a local parts house and bought new 100-amp FRN Time Delay fuses. Everything is up and running!

Thanks Ken. :thumbsup:


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## drsparky (Nov 13, 2008)

Take a bow Tool.:clap:


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## MDShunk (Jan 7, 2007)

I'd encourage everyone to at least consider that a certain fuse type _may have_ been used in commercial occupancies to achieve selective coordination of the overcurrent devices. It's quite possible that the electrician who changes fuses out to one's with different time delay characteristics today might be the guy responsible for the main dumping the whole place tomorrow. When you're on the job, you can sorta get a 'vibe' of whether this is a selective coordination type of place or not. Sometimes you can just look around and think to yourself "maybe" or "no way in hell" this place had a coordination study.


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## Minuteman (Dec 29, 2007)

MDShunk said:


> I'd encourage everyone to consider that a certain fuse type _may have_ been used in commercial occupancies to achieve selective coordination of the overcurrent devices. It's quite possible that the electrician who changes fuses out to one's with different time delay characteristics today might be the guy responsible for the main dumping the whole place tomorrow.


I could see that is some cases Marc. However, to feed a 100-amp main lug panel, I didn't foresee a problem. I could have just bypassed the fuses, since the circuit was feed from the outside MDP.


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## MDShunk (Jan 7, 2007)

Minuteman said:


> I could see that is some cases Marc. However, to feed a 100-amp main lug panel, I didn't foresee a problem. I could have just bypassed the fuses, since the circuit was feed from the outside MDP.


I guess what I'm trying to explain is that fuses are sometimes purposely installed between an MDP branch breaker and a panel for the sole purpose of meeting selective coordination requirements to localize the fault. Hard fault in that panel or one of it's branches and the fuses pop before the main serving the MDP does. Maybe your MDP had no main? That might be what you're saying.

(PS... I dumped an entire wing of a mall with a fault on a 20 amp circuit in a jewelry store I was working in. Hard lesson. )


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## Minuteman (Dec 29, 2007)

See, know I have to rethink the whole thing. Since the MDP has a 1600-amp Main. :blink:


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## MDShunk (Jan 7, 2007)

Minuteman said:


> See, know I have to rethink the whole thing. Since the MDP has a 1600-amp Main. :blink:


Was this place even nice enough or seemingly well wired that someone would have ever done the whole selective coordination study? That's sorta what I was talking about earlier. If it's just add-on after add-on, chances are that these are just leftover fuses from something and you did the right thing. If the place looks pretty well done, those fuses might have been part of some selective coordination effort. Hard to say from where I'm sitting, but on the job you can get sort of a visceral feeling whether that might be true or not.

On the bright side, I've never seen NON fuses used as part of a selective coordination effort, but they could come in darned handy in a retrofit type situation. You'd normally find Class J's used with maybe something like RK5's downstream. You're probably fine, but I just wanted to at least put the bug in people's ear to not start changing fuses out to one's with different delay characteristics in a commercial application without at least pausing to think about the possible repercussions.


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## Minuteman (Dec 29, 2007)

I see what you mean. The buildings are a mix match/hodgepodge of additions. The cafeteria and gym are about 40 years old. The hall and Kitchen panels are Frank Adams. The MDP was upgraded by our company in 2005 when they Air Conditioned the Gym. I doubt that there was any sort of cohesive plan.


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## kbsparky (Sep 20, 2007)

MDShunk said:


> ....(PS... I dumped an entire wing of a mall with a fault on a 20 amp circuit in a jewelry store I was working in. Hard lesson. )


Yeah, ditto here as well. We were working on a simple EXIT sign, when a nick in the wire insulation on the incoming hot line shorted out on the connector. BOOM! 

Blew out the 2000 Amp main in the electric/meter room and took out a couple dozen stores! The ground-fault device in that 480 Volt main blew, but the 20 Amp 277 volt breaker in the store never flinched.


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## RePhase277 (Feb 5, 2008)

kbsparky said:


> Yeah, ditto here as well. We were working on a simple EXIT sign, when a nick in the wire insulation on the incoming hot line shorted out on the connector. BOOM!
> 
> Blew out the 2000 Amp main in the electric/meter room and took out a couple dozen stores! The ground-fault device in that 480 Volt main blew, but the 20 Amp 277 volt breaker in the store never flinched.


You guys are setting bad examples, you and MD... everyone knows there is not one single solitary reason to ever, ever, ever even consider contemplating the thought of dreaming of the possibility of working on a live circuit, especially without a 5' thick concrete blast wall and a space suit on:whistling2:


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## MDShunk (Jan 7, 2007)

InPhase277 said:


> You guys are setting bad examples, you and MD... everyone knows there is not one single solitary reason to ever, ever, ever even consider contemplating the thought of dreaming of the possibility of working on a live circuit, especially without a 5' thick concrete blast wall and a space suit on:whistling2:


In my case, I was changing a ballast and things got outta hand. I confess. :laughing: Sounds like KBSparky might have been changing an exit sign lamp and jiggled the fixture.


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## Minuteman (Dec 29, 2007)

MDShunk said:


> In my case, I was changing a ballast and things got outta hand. I confess. :laughing: Sounds like KBSparky might have been changing an exit sign lamp and jiggled the fixture.


Hacks :whistling2:


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## kbsparky (Sep 20, 2007)

MDShunk said:


> In my case, I was changing a ballast and things got outta hand. I confess. :laughing: Sounds like KBSparky might have been changing an exit sign lamp and jiggled the fixture.


Got THAT right!

Who'd thunk that a simple light bulb changeout would result in knocking out power to a couple dozen mall stores?


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## RePhase277 (Feb 5, 2008)

kbsparky said:


> Got THAT right!
> 
> Who'd thunk that a simple light bulb changeout would result in knocking out power to a couple dozen mall stores?


You can only keep a single bullet for your gun in your shirt pocket from now on...


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## Toronto Sparky (Apr 12, 2009)

MDShunk said:


> In my case, I was changing a ballast and things got outta hand. I confess. :laughing: Sounds like KBSparky might have been changing an exit sign lamp and jiggled the fixture.


I always shut the building down before I change lamps.


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## frenchelectrican (Mar 15, 2007)

Minuteman said:


> See, know I have to rethink the whole thing. Since the MDP has a 1600-amp Main. :blink:


 
1600 A ? Yikes but if the MDP is 480 volts then it will do it.



Now let get back to track as I was going to answer 480's question from my past expernice with some mobile home the underground cable can age and crack open and anytime get bad weather like rain it will shorted out which it did happend to one mobile home park not just too long ago but not in 100 amp size it was freaking 200 amp verison pull out main fuse set up and each time it rain the rain water get into side of meter pedsteal and short it out :blink:

To slove that one end up replacing the meter pedestal and put in correct OCPD in there.

Merci,Marc 

P.S. Ouis { yeah } I do carry extra FRN fuse with me all the time { something I will run into more than once }


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## lobohodge (Jul 6, 2009)

Put Time Delay Fuses in


480sparky said:


> So, last night, just as I started cooking supper (
> 
> 
> 
> ...


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## Toronto Sparky (Apr 12, 2009)

Still say I had the answer in post #2 ...LOL
Just cause I didn't say FRN..

Time Delay HRCs (high rupturing capacity)


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## Minuteman (Dec 29, 2007)

Minuteman said:


> My apologies to 480Sparky. I'm now very glad that he started this thread.
> 
> I got an emergency call today at a privet school cafeteria. One of those, "half the power is out" type. Two rows of lights were out. There are three 120v. reach in freezers, but one had no power.
> 
> ...


Once again, thanks Ken.


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## Toronto Sparky (Apr 12, 2009)

Schools are the worse.. So many guys from so many company's and a few caretaker wiring jobs make them a mess.


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## MAKALUA09 (Mar 29, 2009)

*guessin*

answer please

I'm guessing you checked load side and power was perfect, then you pulled out the fuse and checked the fuse for a calibrated resistance and found out the fuse was bad so you changed it. OLD FUSE?:no:


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## vinster888 (May 3, 2009)

kbsparky said:


> Yeah, ditto here as well. We were working on a simple EXIT sign, when a _*nick in the wire insulation on the incoming hot line shorted out on the connector*_. BOOM!
> 
> Blew out the 2000 Amp main in the electric/meter room and took out a couple dozen stores! The ground-fault device in that 480 Volt main blew, but the 20 Amp 277 volt breaker in the store never flinched.


was that mc cable w/o an antishort perhaps. im not looking for trouble just statistics.


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