[Missouri Bound]

Most homes that I have seen here (in the boonies) have either a 100 or 200 amp service. The wire which the POCO supplies to these homes appears to be the same size. Is that typical? Is there a standard size used by the POCO when establishing a service? The reason I ask is that so many times a sub-panel (or 2) is added to the main panel. Is there sufficient wiring in place to the service for these additions? How can a homeowner determine this?

 

[frenchelectrican]

Most homes that I have seen here (in the boonies) have either a 100 or 200 amp service. The wire which the POCO supplies to these homes appears to be the same size. Is that typical? Is there a standard size used by the POCO when establishing a service? The reason I ask is that so many times a sub-panel (or 2) is added to the main panel. Is there sufficient wiring in place to the service for these additions? How can a homeowner determine this?

The service drop from POCO side they are pretty much standard size and the POCO will know pretty much how much load they are using. It don't matter if 100 ou 200 amp service is used.

The key part what POCO do use is the base load number that how they can get away with it. they don't bother to upsize the drops unless ya got 320/400 amp service it may bump up but if tankless electrique water heaters for sure they will upsize the drop right there ( useally after the transfomer blow the smoke out of the lid )

Most average load on most home AFAIK useally about 30 to 40 amp somewhere that number ( about 6 - 10 KW ) ditto with their POCO transfomer they only use big as possible so most common resdential transfomer useally 15 or 25 KW size which that is the two most common size but there are larger one ( used to feed multi homes )

Merci,
Marc

 

[flasherz]

As I was installing the subpanel for my electric car charging station, I called the PoCo (rural co-op) out to assess my infrastructure. My home was built in 1991. I had 200 amp service provided on 2/0 AL cable from a 15 kVA pad-mounted transformer (sole home on the transformer). According to PoCo models and records, there were times I was drawing nearly 200% of the rated load of the transformer. They asked me if I had any dimming of lights or noticed anything out of the ordinary -- and I hadn't.

When I told them I was adding an 80A continuous charging load for the car, they agreed they should replace the transformer, drop, and meter. They put in a 37.5 kVA transformer, 350 kcmil compact conductor feed, and a 320/400 meter base.

Bottom line: they're permitted to oversubscribe just a bit. They rely upon you to call them when you add something significant that might cause a problem. I've seen more than 1 installation of a heavy EV charging load cause a transformer to percolate oil.

 

[rrolleston]

When we upgraded our service to add an electric tankless water heater and electric heat. They ran 4/0 wire. I think what they run depends on what your load calc is.

Sent from my iPhone using DIY Forum

 

[Oso954]

Each utility can set its own standards, which are often approved or agreed to by a state regulatory agency.

But yes it is common (for over head service) for the POCO to use one size, whether the service is 100 or 200.

As long as the sub panels you are talking about are fed from that main panel, the service limit is set by the main breaker. So, a 100 amp in the main panel would mean 100 amp service.