sgreany
Member
- Location
- massachusetts
I am constantly running into 200a commercial services that the original installer used 4/0 aluminum as the service conductor. I am not going to quote the code here but we all should know that we can not install wiring tthat is supplied by wiring that contains code violations as we become liable for the existing wiring we attached to. Therefore the way I see it I can not do any wiring on the premise if the service is in violation. Do you agree? Also I would like to know why the electrical inspectors are passing these 200a commercial services using 4/0 al. When the required wire size is 250mcm al. I certainly am not the smartest guy in the trade and I am open to being factually corrected (that includes my bad spelling and grammer skills)
I forgot I posted this a wile back and never followed it up.
ART. 230.90(a)
Un-grounded conductors of a service "shall be provided by an over current protective device in series with each un-grounded service conductor that has a rating or setting not higher than the allowable ampacity of the conductor"
If your using aluminum conductors its 250 MCM for single phase. If you go three phase and apply the de-rating table for more than 3 current carrying conductors you need 350 MCM
I forgot I posted this a wile back and never followed it up.
ART. 230.90(a)
Un-grounded conductors of a service "shall be provided by an over current protective device in series with each un-grounded service conductor that has a rating or setting not higher than the allowable ampacity of the conductor"
If your using aluminum conductors its 250 MCM for single phase. If you go three phase and apply the de-rating table for more than 3 current carrying conductors you need 350 MCM