Getting ready to start a new build using geo with vertical wells. I am talking with my electrician who does many of my commercial projects, so he does great work, I can trust him, so why not have him help on my own house? Anyway, we were talking about the service size to the house. I just assumed all along a 200a service, but he said if I was wanting geo I need to up it to 300-400a service. The proposed system is a WF, 2 ton unit and 7kw electric heat strip. Loads in the rest of the home will be hopefully lower, with ES lighting and appliances, gas range, etc. Any thoughts/input on this? I find it hard to believe that I would need a service this large.

200 amp is plenty for our 3-ton WF NDV038 with DSH
and 10 kW heat strip, on a vertical closed loop (in PA).

Everything else in the house is electric, too -- cooking,
clothes dryer, well pump, etc. No combustion, no solar.

We initially experienced a noticeable (but not otherwise
troublesome) dimming of lights at compressor start-up,
but a WF Intellistart eliminated that annoyance entirely.

BTW, the lamp dimming was primarily due to a very long
(and somewhat undersized) above-ground feed from our
rural electric service. So, it might not hurt to oversize
the service connection a little -- but the 200 amp panel
is more than adequate for our needs.

WF now offers Intellistart as a factory-installed option.
IMO, it should be standard equipment -- it would be
foolish to order a WF heat pump without one.


Looby

Sounds like 200A is fine

Posted By Looby on 20 Mar 2012 10:54 AM

WF now offers Intellistart as a factory-installed option.
IMO, it should be standard equipment -- it would be
foolish to order a WF heat pump without one.

+1.  Extremely useful for a standby generator too.  Factory installed IntelliStart should be reasonably priced, and should be eligible for the 30% tax credit (since the price is rolled into the unit cost.)  Same story on our lights dimming pre and post IntelliStart.

200 amp service here too.  We have 5 tons split between two units.  Electric water heater, but propane dryer and range.

You sure you trust your electrician for your own house? It sounds like he is either way off or just doesn't have a freaking clue. 7KW should be about 45 amps I think, normally every 5KW is 30 amps, plus a two ton unit is only 20-30 amps at most. And as others have said, intellistart should be included with every unit, we don't sell a unit without it.

One of our utilities has begun requiring soft start.

Since I've heard that inverter based mini-splits are the solution to everything (that's a joke), has anyone measured to see if they do a slow start that would make them work with small generators?

Posted By jonr on 23 Mar 2012 03:11 PM
Since I've heard that inverter based mini-splits are the solution to everything (that's a joke), has anyone measured to see if they do a slow start that would make them work with small generators?

I have never measured but everything i have seen from the manufacturer shows that they soft start because in Japan and high density areas where these are prevalent they require it.

Hi and thanks for the EDU !

@ 10 kw , although using 60a breakers for heat and sometimes #4 thhn for carry through unheated spaces;
I have found 43-46 amps on 240-250 volts; -and 22-23 a on 5kw strips.

old 100a services have had no problem (exchanging to better panels with job) with 35 a RLA and smaller with even 10KW strips (5, wired separately-contacted, for emergency use ) - also b/c of the Dual Compressor 3-Staging, in a smallest 17MBTUh and 23MBTTUh combo "rated's size 4.0 " sometimes, it acts as a pretty soft start, and no-problem starts with 12 hp generator in one case only seen.
200a , depending on all else totaling:
actual running combined under 80% at under 160 amps, has worked with 2) 4-size, and 15 kw strips (KW alone 66-68amps), clean-cool-pasted breaker contacts throughout panel setup and sub panel(s).

BRISTOL's V- is adjustable to 5-staging set or other.