4awg big enough from pole to house? 400a panel

[Craigv]

Earlier this year I upgraded a 200a service to 400a (320) to accommodate a tankless water heater that required four 40a circuits. I asked the POCO about the underground conductors being up-sized.

"Nope."

In fact, I received the same response when inquiring about a 200-to-600a upgrade for a bitcoin-farming installation.

Yeah you never know what you will get. I added a 5th meter for a 5th apartment on an existing service. POCO did upgrade the drop but not the tranny. They say if a utility doesnt burn up a few transformers and service drops now and then, they are sizing them too big

I installed a 12-space RV pedestal service...two 200 amp services on a common drop. All new to the space. PoCo came out, deemed the existing transformer adequate, told me the crew would string a 4/0 drop to my pole. They ran 2/0, one of the crew tried to tell me it was 4/0 and I laughed at him (my two SE drops were 4/0...it isn't *that* high up you can't see the difference), told my customer about it, and we'll see how it goes next summer when there's a big demand on the system. Prolly be just fine. Might burn up the old transformer. I'm paid, customer is happy, campers are happy.

 

[ggunn]

right, but did they add loads?

In California, changing from a 100A to a 400A service... I wonder what they are doing...

 

[roger]

Since we do not have the actual load calculations we can not come to a real conclusion so, the OP needs to have someone knowledgeable do a calculation and then come back, or better yet, take it up with the POCO with actual numbers.

Roger