3 phase service drop

[darryljcooper]

I have a commercial builder owner that wants to put a new meter and 100 amp panel for a diffent part of his building that he will be renting out. my question is this? the service drop to his building is a 3 phase 4 wire 240 volts. he wants me to put a single phase meter and panel from the 3 phase service drop. CAN I DO THIS BY THE NEC CODE? ALSO ON THE BUILDING IS TWO OTHER METERS WITH TO DISCONNECTS ON IT #1 IS A 200 AMP, THE OTHER IS A 100 AMP. HOW DO YOU DETERMINE DO THE SERVICE DROP HAS ENOUGH AMP? TO ADD ANOTHER 100 AMP METER AND PANEL?

[ May 23, 2003, 11:10 PM: Message edited by: darryljcooper ]

 

[tom baker]

Re: 3 phase service drop

A single building or structure is limited to one service, unless a different voltage or phase is required, or exceeds a certain ampacity.
I would first check with your serving utility and see what there regulations are. Then find out why there are other services.
If its for a different tennant, then typically a larger service with seperate meters is used, not an entirely new service. Have you reviewed NEC Article 230 Services?

 

[frenchelectrican]

Re: 3 phase service drop

becarefull with expanding exsting service my poco regulation say if have 3 ph delta service exsting will only increse to match over current device only other wise will have to go with wye connetion ( 120/208 volts ) and my best bet is try to check the poco if can retap the transfomer to wye i know delta service is going gone pretty fast now right now only few places still have old delta service but will check on load demand on both single and three phase to verify it

merci marc

 

[bob]

Re: 3 phase service drop

I'm sure you know that you are limited to the number of disconnects on the building. They should all be located in the same general area.
You do not need to worry about the service conductor capacity. Thats the utility's problem.
You should contact them and advise them what your plans are. They should send a rep out to check the transformers and service drop. If the voltage is 120/240 three phase, I would not think they would object to you adding a 120/240 single phase
panel.

[ May 23, 2003, 02:48 PM: Message edited by: bob ]