Incoming Service
Incoming Service
(OP)
I am helping with the electrical design for a renovation of a building in Elkton, Maryland. It will require an electrical upgrade to about 1000-1200A. The existing MDP's have 120/240V and the electrical panels in the building are also 120/240V or 115/230V. There is a pole mounted transformer outside. The power company has informed me that they would much rather bring in 120/208V to the building. I would like to know if this takes place, if all the electrical panels would have to be replaced because of this change in incoming service (MDP's are already being replace). I understand that there will be some de-rating of the motors. The panels are for lighting, receptacles, hvac equipment, etc. We would like to avoid this from happening due to costs. Please share any knowledge on this matter. Thank you very much.






RE: Incoming Service
If the existing service is single-phase, you might be better off bringing in a new 480V service for the new loads and sub-feeding the existing panels through some transformers.
I'd be surprised if any utility is going to provide a 1200A 120/240 service.
RE: Incoming Service
Then you also need to determine if any 240V equipment connected is going to tolerate 208V. Most will, but it is not for sure.
Eng-Tips: Help for your job, not for your homework Read FAQ731-376
RE: Incoming Service
In which case again the compressors fry. Recently they have started coming out with 208 compressors. These work fine on 208.
So I would say that probably all your HVAC compressors would definitely be put at risk if you change to 208.
We always try very hard to get customers to let us put in boost transformers when we are faced with the miserable 240/208 compressors being fed with 208.
So you could still switch the plant to 208, you will just need to boost all the comps. Not a big deal cuz you're just transforming the boost with a wall mount tranny. As the comps are replaced over time you can just use 208 versions. Like I say not a big ordeal .. But an effort.
RE: Incoming Service
Go-go cage dancer at a San Francisco bar?
LOL. Gotta be careful with terms like that around here, eh?!
Sorry, couldn't resist. RF it once you've read it itsmoked.
Eng-Tips: Help for your job, not for your homework Read FAQ731-376
RE: Incoming Service
You can get away with it in a residential setting, where things like water heaters and electric resistance will work OK. But any 240V motors will suffer.
RE: Incoming Service
Hey I don't need to RF it since only you or me understand this local environ.
RE: Incoming Service
RE: Incoming Service