Maximum Electrical Services?
- Thread starter GotPower?
- Start date
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jetlag
Senior Member
- Location
- Eatonton, Georgia
I will add rersidential is limited to single phase , 120 v line to neutral .:grin:
Pierre C Belarge
Senior Member
- Location
- Westchester County, New York
jetlag
Senior Member
- Location
- Eatonton, Georgia
International residential code E3502.4 Voltage rating ,Systems shall be three-wire 120/240-volt single phase with a grounded neutral . If its not in the NEC it needs to be added :roll:
Pierre C Belarge
Senior Member
- Location
- Westchester County, New York
Are you saying you have never seen a 3phase service to a dwelling?
The Residential Code does not restrict one from installing a 3 phase system. If one does install a 3 phase system, then the installer will be required to follow the NEC in it's entirety, not being able to use the residential code and some of the relief it permits in the installation as compared to the NEC.
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ceb58
Senior Member
- Location
- Raeford, NC
The way an inspector explained it to me that they would allow it was if you had a building that was served by 120/240 SP and machinery was brought in that requried 480 3ph. Then they would allow the second service to be installed. But if the same building was served with 120/208 or 120/240 3ph they would not allow the second service because transformers could be set to accommodate the 480 3PH equipment. Now that was their ruling here and it may be different where you are at.
jetlag
Senior Member
- Location
- Eatonton, Georgia
On on multifamily dwellings where 3 phase equipt was used in a central laundry or club house area , it is not allowed to run 3 phase into each dwelling panel. Any way when I made the post I was talking about single family dwelling when I said residential . You always want people to prove things, you prove the above post , it is not stated in the IRC or NEC
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Submit a proposal then. New codes don't just magically appear.
Now tell me how to wire a 60-unit apartment building when all I can get is 120/208 three phase.
Pierre C Belarge
Senior Member
- Location
- Westchester County, New York
Read:
E3301.2 Scope
Specifically the 2nd and last sentences.
I would type it out, but it is too long for my slow fingers tonight.
jetlag
Senior Member
- Location
- Eatonton, Georgia
I dont think you will get any support on that , what you are refering to is things that are not specifically covered in the IRC are not to be considered exempt from the NFPA 70 . Single phase 240/120 volt service is "specifically covered" in E3502.4 for one and two family dwellings .
Pierre C Belarge
Senior Member
- Location
- Westchester County, New York
Read it again.
If one does not install services sized as per this section, then the residential code does not apply and one is to follow the NEC.
It may be different in different states, that I do not know. The book I took this from is the Residential Building Code of NYS. I know that it is similar to most other documents that some states are referencing.
If one does not install services sized as per this section, then the residential code does not apply and one is to follow the NEC.
It may be different in different states, that I do not know. The book I took this from is the Residential Building Code of NYS. I know that it is similar to most other documents that some states are referencing.
jetlag
Senior Member
- Location
- Eatonton, Georgia
Why would any one want a delta high leg ran into their house panel ? you can get 400 amp 240/120 . enough to pull a small factory . I sure dont want 208 Y , and have to buy all 208 eguip or use 208/240 that operates at reduced power. ITs not just the AHJ , the poco around here would never hit a one or two family dwelling with 3 phase line , delta or Y , Y here is strictly commercial , and they darn sure wont run a high leg in a house. I have 3 phase delta on my shop / office that has an upstairs apartment , I cant say for sure in a case like that if 3 phase can be ran to the apartment sub panel , I never would do that , but that is not considered a one or two family dwelling building.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
I know of two different 3ph services in homes.
The first one is a typical 120/240v 100a service with a smaller conductor for the high leg, for the central-AC compressor unit.
The other is a 400a 208Y/120v to a rather large house. In fact, the three transformers supply only this one premises.
The first one is a typical 120/240v 100a service with a smaller conductor for the high leg, for the central-AC compressor unit.
The other is a 400a 208Y/120v to a rather large house. In fact, the three transformers supply only this one premises.
- Location
- Massachusetts
Yeah, we do.
We like to de-bunk myths and we do not like to spread new ones.
We ask anyone that says something is a 'rule' to show us that rule.
Is that wrong?
I would not, but the real question is why would it be against the code to do so?
208 is used often and if you look at electric stoves and dryers you will notice they are rated for 240 or 208.
There are entire neighborhoods in the cities around me where the power company runs a 208Y/120 volt network and each single or small multi family home will be served by two legs of that network resulting in 208/120 single phase services at single family homes.
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jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
- Location
- Illinois
- Occupation
- retired electrician
There are areas where the utility does not provide 120/240 single phase power to dwelling units. In some neighborhoods, the dwelling unit is supplied with two ungrounded legs and a grounded conductor from a 208/120Y system.
Sorry, Bob,
I did not read all of the posts before making this one
jetlag
Senior Member
- Location
- Eatonton, Georgia
Yeah, we do.
We like to de-bunk myths and we do not like to spread new ones.
We ask anyone that says something is a 'rule' to show us that rule.
Is that wrong?
I would not, but the real question is why would it be against the code to do so?
208 is used often and if you look at electric stoves and dryers you will notice they are rated for 240 or 208.
There are entire neighborhoods in the cities around me where the power company runs a 208Y/120 volt network and each single or small multi family home will be served by two legs of that network resulting in 208/120 single phase services at single family homes.
If 208 is all thats there, you have to take it. I gave the reason I dont like it , 208/240 equipt runs at lower watt output on 208 , except for some that have separate connections. I believe the two houses you mentioned are old and at some point were partly commercial , The poco wont run a 3 phase just because you want to use a 3 phase a/c in a 1 or two family dwelling , call the poco and ask. Also I still stand by IRC-E3502.4 , I see nothing that proves you can disreguard that and run 3 phase to one or two family dwelling.
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