Cost of extra receptacles

[suemarkp]

No criticism or negativity, just want to be educated.

I am always curious why someone needs a 400A service for their house? Even at 0.8 PF that is 76kW ! PSE probably only has a 50kVA (or less) distribution transformer to feed you? Only load I can think of would be a couple of huge wonkin' on-demand electric water heater plus +++.

Well, the NEC load calc came to about 360 amps (using the Optional calc -- was over 400 with the Standard calc). This house is all electric (no gas available unless I wanted to pay for a main extension). It has a 4 ton heat pump with 20KW aux heat, a swimming pool with 2 water pumps which also has a heat pump (but I assumed the house aux heat was non-coincident with the pool heater, since it is summer use only, so it didn't get added), two kitchens each with an electric range and 2 small appliance circuits, two laundries each with an electric dryer and laundry appliance circuit, one 5500W water heater, and a workshop with a bunch of tools (but I only put in the largest tool at 3.3 KVA for that since I'm a one man shop).

I wanted a larger transformer (they were going to give me a 25 KVA "for free") so had to pay extra for the 50 KVA unit out there on the pole. They ran 1/0 aluminum to the mast and I wanted larger. Was supposed to be 2/0 or 4/0 aluminum and an additional $300. But when the Potelco truck showed up, all they had was the 1/0 and no additional fee... Looks kind of funny to have a 400KCMil copper conductor with a little 1/0 aluminum connected to it).

I doubt I ever draw much more than 200A, even in the winter, and a 200A or 225A main would probably have worked. But the NEC load calcs and reality never seem to match. I'm surprised the triplex was never steaming in the winter though...

 

[kwired]

No criticism or negativity, just want to be educated.

I am always curious why someone needs a 400A service for their house? Even at 0.8 PF that is 76kW ! PSE probably only has a 50kVA (or less) distribution transformer to feed you? Only load I can think of would be a couple of huge wonkin' on-demand electric water heater plus +++.

Though the average dwelling doesn't really have that much load, some do, like mark mentioned with electric heat, sometimes the load can add up pretty fast. I did a rather large home a few years ago that had 60 kW of heat, plus the remainder of the house to supply. Electricity is pretty cheap here compared to other parts of the country, especially during heating season as rates go down at that time of year because the demand goes down. Utilities lower rates to encourage more usage during the low demand season, otherwise they have infrastructure that is not really used to its ability yet it costs a certain amount to operate whether loaded or not.

Electric heat was actually cheaper than heating with gas a few years ago, but I think gas is a little less now, but electric is still somewhat competitive price wise.

 

[junkhound]

Thanks, interesting.

Last service I installed in Kent was last March.
No load calcs needed, WA state permit inspection only for Kent I found. Other cities do have their own elec permit process and may require load calcs.
March install was straight 200A and has on-demand elec water heater and heat pump.
Only thing PSE really wanted to know was LRA for heat pump and tankless WH current - PSE primarily interested in if >3% droop at xfmr (3 existing neighboring 4500 sq ft houses on existing 37.5 kVA xfmr)
PSE did tell me anything above 1.8 GPM tankless heater would drive a 50kVA xfmr upgrade - installers cost, so did install smaller WH than originally planned.

Potelco did pull 175 ft of 4/0 Al for the underground service for the standard PSE new service fee, so did not have to deal with voltage drop on service like your install. Interestingly, Potelco crew had to call in to see if my 4" sch 80 PVC conduit* was OK (vs 3" that 'the book' says). PSE told them it could be a 2 ft conduit, just over 3", was surprised Potelco needed to get an OK?
*note - why? - got the 200 ft of the 4" left over from a street light job