# 4 wire delta meter question.



## RodDriver (Nov 9, 2019)

Getting 120 to ground, 240 between legs, and 208 on the wild leg. This is a 4 wire delta correct?

I have to upgrade the 200A meter to something larger. Will I have to replace the meter socket? If so, what am I looking for? I see the meter says form 16S. Are a 200A and say a 400A physically different? The socket looks like it probably handles more than 200A judging from the extra room in the lugs. Sure would appreciate any help.


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## Forge Boyz (Nov 7, 2014)

That is nowhere near big enough for 400A. You will either need a 320A base which is good for a nominal 400A service, or if you want a full 400A continuous service you will need a CT cabinet. Check with your POCO to see what they will allow you to use.

Sent from my SM-G970U using Tapatalk


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## Majewski (Jan 8, 2016)

RodDriver said:


> Getting 120 to ground, 240 between legs, and 208 on the wild leg. This is a 4 wire delta correct?
> 
> I have to upgrade the 200A meter to something larger. Will I have to replace the meter socket? If so, what am I looking for? I see the meter says form 16S. Are a 200A and say a 400A physically different? The socket looks like it probably handles more than 200A judging from the extra room in the lugs. Sure would appreciate any help.
> View attachment 162245
> View attachment 162245


You can’t legally use equipment over the listed amperage.


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## Slay301 (Apr 23, 2018)

Good luck finding 320 base meter socket they are running 9 months out


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## gpop (May 14, 2018)

Why is the high leg a smaller gauge wire. Is this a residential setup.


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## Majewski (Jan 8, 2016)

gpop said:


> Why is the high leg a smaller gauge wire. Is this a residential setup.


Mhm


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## Slay301 (Apr 23, 2018)

Majewski said:


> Mhm


huh?


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## Majewski (Jan 8, 2016)

Slay301 said:


> huh?


Indeed


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## Slay301 (Apr 23, 2018)

Majewski said:


> Indeed


Undeniably


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## RodDriver (Nov 9, 2019)

gpop said:


> Why is the high leg a smaller gauge wire. Is this a residential setup.


No, perhaps because it only runs a rooftop AC unit.


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## gpop (May 14, 2018)

I can see they are using what looks like 30 amps 3 phase judging by the size of the disconnect on the right and 200 amps single phase to a interior panel i have just never seen this type of setup so im asking if its normal. E.g can i get poco to install one at my home.


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## Majewski (Jan 8, 2016)

gpop said:


> I can see they are using what looks like 30 amps 3 phase judging by the size of the disconnect on the right and 200 amps single phase to a interior panel i have just never seen this type of setup so im asking if its normal. E.g can i get poco to install one at my home.


Just do it and feed the lineys lol


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## paulengr (Oct 8, 2017)

It’s called high leg delta.

The three phase legs are a normal 240 V delta feed. The utility side can be 2 or 3 coil but from your perspective you don’t care. All you care is you have 240 V 3 phase delta service.

The fourth wire is a neutral that is center tapped on one of the transformer secondary coils giving you a single phase “120/240” service where the two phase conductors are shared with the 3 phase service. The voltage from this neutral to the third phase, the “high leg”, is 208 but that’s not something you should use for a load. It is only important because you can hook single phase 120 V loads to two of the phase conductors but you need to avoid connecting single phase loads to the high leg, NEC says we must mark this one as orange and the neutral as the usual white or grey. The other two can be any color by Code. Convention for 240 would be black blue red but NEC breaks convention. I’ve seen blue orange red, black orange black (120/240 convention) and brown orange yellow (480 V convention). The only safe way to be sure is measuring voltages.


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## Majewski (Jan 8, 2016)

Totally looks marked too.


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## matt1124 (Aug 23, 2011)

Black orange blue in this city, local amendment. 

Put your LEDs that can range 120-277 on the high leg, use up those extra breaker spaces, if poco don’t like it they should have put 3 pots 🤣


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## matt1124 (Aug 23, 2011)

gpop said:


> I can see they are using what looks like 30 amps 3 phase judging by the size of the disconnect on the right and 200 amps single phase to a interior panel i have just never seen this type of setup so im asking if its normal. E.g can i get poco to install one at my home.


POCO told me on my home, when I built the 400 amp service, that I could have anything I wanted to pay for. I thought about trying to get a wing pot but I didn’t want to buy a transformer! I did put a big enough pipe in the ground for later though! 

Some houses here have high leg available in the older nicer parts of town. Outside panel will be three phase, usually just a disconnect for the A/C, inside single phase. Older commercial here will actually have two meters. It’ll be one quadruplex drop, one with all 3 legs going to a meter and panel, one with only the split phase part going to a meter and panel.

what I think is dumb that people do here on the houses, it’ll be a quadruplex drop, and it’s all hot and working and available, and they’ll just curl back the high leg and tape it off at the weatherhead and put single phase service equipment. I’d be taking advantage of that if it were me


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## micromind (Aug 11, 2007)

This is indeed a 120/240 3Ø 4 wire ∆ system. 

The meter socket is 6 jaw, if you're going to single phase, you'll need to replace it with a 4 jaw. 

These were pretty common back in the 70s and 80s, there was either a split-bus single phase panel with a ∆ breaker, usually 30 amp, sometimes 60. This breaker fed the A/C unit only, the rest of the panel was single phase. 

The other option was a 200 amp single phase main breaker panel (or 150 amp, depending on how much of a jerk the inspector was.....) and a 30 or 60 amp 3 pole fused disconnect that fed the A/C unit. The one pictured is the latter. 

If there are enough 240 loads (not 120/240) it'd be a good idea to install amain breaker 3Ø panel and use the high leg and one of the other phases for these loads. Do not use the high leg for anything but 3 pole and 2 pole loads that do not involve the neutral. 

Maybe install 2 panels, one single phase and a smaller 3Ø one. Both will need main breakers.


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## micromind (Aug 11, 2007)

matt1124 said:


> what I think is dumb that people do here on the houses, it’ll be a quadruplex drop, and it’s all hot and working and available, and they’ll just curl back the high leg and tape it off at the weatherhead and put single phase service equipment. I’d be taking advantage of that if it were me


Agree 100%!!

If I can use the high leg for anything, I will always have a 3Ø panel and usually a single phase one as well.


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## RodDriver (Nov 9, 2019)

Forge Boyz said:


> That is nowhere near big enough for 400A. You will either need a 320A base which is good for a nominal 400A service, or if you want a full 400A continuous service you will need a CT cabinet. Check with your POCO to see what they will allow you to use.
> 
> Sent from my SM-G970U using Tapatalk


Thanks. 320A will do. Trying to keep the cost down.


micromind said:


> This is indeed a 120/240 3Ø 4 wire ∆ system.
> 
> The meter socket is 6 jaw, if you're going to single phase, you'll need to replace it with a 4 jaw.
> 
> ...


The meter is only 200A. He has a 200A panel that is too small. I don't think it's very cost effective to bother the high leg. I'm thinking upgrade the meter, use pass through lugs, and add another panel.


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## Norcal (Mar 22, 2007)

matt1124 said:


> Black orange blue in this city, local amendment.
> 
> Put your LEDs that can range 120-277 on the high leg, use up those extra breaker spaces, if poco don’t like it they should have put 3 pots 🤣


Standard residential breakers cannot be used on the high leg, they are rated 120/240V & the high leg exceeds the lower voltage.


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## Almost Retired (Sep 14, 2021)

Norcal said:


> Standard residential breakers cannot be used on the high leg, they are rated 120/240V & the high leg exceeds the *higher* voltage.


fify


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## matt1124 (Aug 23, 2011)

Norcal said:


> Standard residential breakers cannot be used on the high leg, they are rated 120/240V & the high leg exceeds the lower voltage.


I know but wouldn’t it be nice if such a thing existed? How many panels have you found “full” where you could have used this


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## matt1124 (Aug 23, 2011)

Almost Retired said:


> fify


Slash rated breakers are first voltage line to neutral and second voltage line to line. 208 would exceed the line to neutral, lower voltage


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## 460 Delta (May 9, 2018)

Norcal said:


> Standard residential breakers cannot be used on the high leg, they are rated 120/240V & the high leg exceeds the lower voltage.


It’s considered excessively naughty and I wouldn’t think of doing that on a R-Mix plant, especially for a 5kw unit heater.


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## Almost Retired (Sep 14, 2021)

Almost Retired said:


> fify


@Norcal my apologies, i figured out what you meant and I thought i had edited that out
so at this point i now agree with you, and i also did not think that idea was a good one either


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## RodDriver (Nov 9, 2019)

Supply house said Milbank makes one but they are on backorder until 26 weeks from now. Let's go Brandon!


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## Almost Retired (Sep 14, 2021)

look out ebay , here i come


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## matt1124 (Aug 23, 2011)

Almost Retired said:


> look out ebay , here i come


More like look out bank account. I’ve been enjoying selling my milbank stash on eBay lately 💵


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## backstay (Feb 3, 2011)

matt1124 said:


> More like look out bank account. I’ve been enjoying selling my milbank stash on eBay lately 💵


 Didn’t they arrest two guys for that at the start of all this silliness? That was hand sanitizer I think.


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## Almost Retired (Sep 14, 2021)

as i recall .... gouging is against the law for what ever goods you sell
could have been a bunch who needed arresting, but lucked out


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## backstay (Feb 3, 2011)

Almost Retired said:


> as i recall .... gouging is against the law for what ever goods you sell
> could have been a bunch who needed arresting, but lucked out


Unless you’re big business.


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## matt1124 (Aug 23, 2011)

backstay said:


> Didn’t they arrest two guys for that at the start of all this silliness? That was hand sanitizer I think.


I can’t help it that buying out Home Depot of every meter socket means buying the only one they have! 😁


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## RodDriver (Nov 9, 2019)

Detroit area they are stealing Romex and selling it on FB Marketplace. One guy just got caught and hit with a felony. 

PS Milbank said DTE is going to make me go CT cabinet.


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## matt1124 (Aug 23, 2011)

RodDriver said:


> Detroit area they are stealing Romex and selling it on FB Marketplace. One guy just got caught and hit with a felony.
> 
> PS Milbank said DTE is going to make me go CT cabinet.


They roll it out by the cart full. The Home Depot here has made a locking system with pallets, black iron pipe, and spider wire. You have to get them to unlock it with the magnet tool to get a roll. They know me there so they just hand it to me, but I've seen them take it up to the cashier directly.


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## micromind (Aug 11, 2007)

RodDriver said:


> Thanks. 320A will do. Trying to keep the cost down.
> 
> The meter is only 200A. He has a 200A panel that is too small. I don't think it's very cost effective to bother the high leg. I'm thinking upgrade the meter, use pass through lugs, and add another panel.


What do you mean by too small, not enough amps or not enough spaces?

It looks like a 100, maybe 125 amp single phase service with a 30 amp 3Ø service, maybe a 60. 

If it were me, and the load calc will allow it, I'd leave the 3Ø as it is and change the indoor panel to one with more spaces. Unless the house is huge or everything is electric, a 100 or 125 is fine. 

Is the indoor panel main lug, split bus or main breaker?


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## micromind (Aug 11, 2007)

matt1124 said:


> I know but wouldn’t it be nice if such a thing existed? How many panels have you found “full” where you could have used this


Square D makes a QO single pole that's rated 240/415. It'd be fine high leg to neutral but the AIC is only 3000 amps. 

If it's an open ∆ and the ∆ pot is 15 KVA or smaller, you'd be ok though. If it's a closed ∆ you'd likely have more than 3000 amps of available fault current high leg-to-neutral even if it's 3 - 10 KVA pots.


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## matt1124 (Aug 23, 2011)

micromind said:


> Square D makes a QO single pole that's rated 240/415. It'd be fine high leg to neutral but the AIC is only 3000 amps.
> 
> If it's an open ∆ and the ∆ pot is 15 KVA or smaller, you'd be ok though. If it's a closed ∆ you'd likely have more than 3000 amps of available fault current high leg-to-neutral even if it's 3 - 10 KVA pots.


QOXD120…. Would you look at that.


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## RodDriver (Nov 9, 2019)

matt1124 said:


> They roll it out by the cart full. The Home Depot here has made a locking system with pallets, black iron pipe, and spider wire. You have to get them to unlock it with the magnet tool to get a roll. They know me there so they just hand it to me, but I've seen them take it up to the cashier directly.


Let's go Brandon @


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## paulengr (Oct 8, 2017)

backstay said:


> Unless you’re big business.


Banks and credit card companies are exempt from interest rate restrictions the rest of us must abide by.


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## RodDriver (Nov 9, 2019)

So DTE has a whole process for site planning that must be followed before I can learn what to charge. More time to put together a bid the customer will probably reject.


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## matt1124 (Aug 23, 2011)

RodDriver said:


> So DTE has a whole process for site planning that must be followed before I can learn what to charge. More time to put together a bid the customer will probably reject.


Ahh but you’ll know an idea for next time


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## Southeast Power (Jan 18, 2009)

RodDriver said:


> Getting 120 to ground, 240 between legs, and 208 on the wild leg. This is a 4 wire delta correct?
> 
> I have to upgrade the 200A meter to something larger. Will I have to replace the meter socket? If so, what am I looking for? I see the meter says form 16S. Are a 200A and say a 400A physically different? The socket looks like it probably handles more than 200A judging from the extra room in the lugs. Sure would appreciate any help.
> View attachment 162245
> View attachment 162245


Sorry I'm late to the party but, if you are going to upgrade that service, do yourself a favor and use a 400amp fused main disconnect.
Feed a gutter and use one single phase loadcenter for your receptacle and lighting loads and a three phase loadcenter for your motor and power loads.
Im only using the term loadcenter just due to the fact panelboards are usually custom made and for whatever reason take months to get.
The single phase transformer will be happy to serve all of your receptacle and lighting loads and will also work perfect when needed for the 3 phase loads.
This setup will leave a nice legacy for the next electrician.


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## paulengr (Oct 8, 2017)

Southeast Power said:


> Sorry I'm late to the party but, if you are going to upgrade that service, do yourself a favor and use a 400amp fused main disconnect.
> Feed a gutter and use one single phase loadcenter for your receptacle and lighting loads and a three phase loadcenter for your motor and power loads.
> Im only using the term loadcenter just due to the fact panelboards are usually custom made and for whatever reason take months to get.
> The single phase transformer will be happy to serve all of your receptacle and lighting loads and will also work perfect when needed for the 3 phase loads.
> This setup will leave a nice legacy for the next electrician.


SOME manufacturers are slow. In the last few years Siemens has been producing smaller 3 phase panel boards to stock most have this.

Siemens makes most of them in India. So if you order from inventory it’s quick. But if you say specify copper only bus bars for a water plant since silver plated is the standard it becomes made to order from India or hopefully a domestic local small run shop. If you order say a built in meter that may trigger an engineered order. So they may pull a standard panel and send it to a panel shop to modify either under their UL label if it’s an allowed option or Listed as say a field inspection. This adds lots of time.

In normal times electrical parts are seasonal. The capital budget cycle and gas & oil construction cycles drive availability. So O&G in particular hits around March and April and it only gets worse as the construction season heats up. If you put in orders in January and February delivery dates are often 1/4 of other months.

On top of that it can vary tremendously by supplier and with your creativity. At times MCC might be faster than panelboards.


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## matt1124 (Aug 23, 2011)

Southeast Power said:


> Sorry I'm late to the party but, if you are going to upgrade that service, do yourself a favor and use a 400amp fused main disconnect.
> Feed a gutter and use one single phase loadcenter for your receptacle and lighting loads and a three phase loadcenter for your motor and power loads.
> Im only using the term loadcenter just due to the fact panelboards are usually custom made and for whatever reason take months to get.
> The single phase transformer will be happy to serve all of your receptacle and lighting loads and will also work perfect when needed for the 3 phase loads.
> This setup will leave a nice legacy for the next electrician.


You’re gonna be real late to the party lol, last 400 amp fused disconnect took MONTHS to get 🤣🤣


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## RodDriver (Nov 9, 2019)

Southeast Power said:


> Sorry I'm late to the party but, if you are going to upgrade that service, do yourself a favor and use a 400amp fused main disconnect.
> Feed a gutter and use one single phase loadcenter for your receptacle and lighting loads and a three phase loadcenter for your motor and power loads.
> Im only using the term loadcenter just due to the fact panelboards are usually custom made and for whatever reason take months to get.
> The single phase transformer will be happy to serve all of your receptacle and lighting loads and will also work perfect when needed for the 3 phase loads.
> This setup will leave a nice legacy for the next electrician.


Great advice. I don't think as the bearer of bad news I will be doing this job.


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