As I understand these installations, if the generator capacity is less than
the utility company's incoming then the selected circuits are split so only
they are fed emergency power.
I would expect then if the capacity of the generator equaled or exceeded the
utility incoming then both the generator and the utility drop could be fed
to the transfer switch.
What % range of the installation cost might be saved by using a higer
capacity generator set?
The utility drop is not changed , your transfer panel wires to your
Why would you save anything by using a bigger generator, You wont it
will cost more, a heavier unit , more wiring. Maybe a bigger gas line.
I assume this is for ocasional power outages
if you have power coming in, the generator should be operating at zero
capacity. i.e. off.
you want something that turns on when the power goes off. if you cant
handle ANY downtime, put some batteries on it that can power the sytem for
however long it takes to get the generator started after a power failure.
or just put them on the items that you need. like a computer. the fridge
will do fine if the power is gone for a few seconds.
The gentleman's question is what savings there might be on the
installation process for a generator large enough to power the whole
house so that circuits to be powered don't have to be split off to a
seperate panel as is typically done.
I think if you're going to do it one way or the other, get an
electrician out to give you an estimate both ways. I think you'll
find that the install cost difference is small compared to the cost of
a much larger generator. Plus, you have the other problems like the
increased size/weight of a larger unit too.
lets play ping pong.
ok i see it now. and i think you are correct. i would guess the cost of
more generator pales in comparason to the cost of a sub panel.
one thing that comes to mind is that if you understand how a panel works,
some of the circuits run of one leg of the 220, and some on the other, both
using the neutral to get the 110. if you have a 110 generator wouldnt it be
possible to wire it into the panel to energize one side of it without the
other? then with a little clever wiring you put the things you want on the
generator, on that leg of the 220. i dont think any harm will come to the
220 appliences that only have one leg powered, although they wont work
im just thinking outloud...
Some random comments:
Any generator large enough to consider wiring into the panel is going to have 240V.
Even if it was 120V, it's not going to make the code-required transfer
switching any less expensive.
Indeed, with the cheap generators being discussed, the transfer switching
to (partially) energize the panel is going to cost almost as much (or more)
than the generator does, so why not get a generator with 240V capability?
If you wire a small generator fully into a panel, even with the proper
transfer switching, it'll be a moderately complex cutover process.
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.
Actualy Generac sells a complete prewired kit with exterior box, cable,
plugs, and 2 watt meters on the panel for 200. It was a 4 hr instal
complete, the hardest part was drilling through the house.
Lowes often has free panels when you buy a generator.
Yes, only certain loads are on the generator. Even in industry the
generators only run critical loads, usually.
Yes. But it is common for an 1000 amp service to have a 100 or 200 amp
Using this as an example only. It depends on the load of the critical loads.
Transfer switches start out at 30 amps and the largest I have ever done was
There are manual ones and automatic ones. The automatic ones have a variant
that is a load sharing, similar to a soft start. CH makes this one as well
as others. Not small I believe these are 1200 amp.
Savings for a bigger genset, absolutely not. Bigger is more money
absolutely. Manual is less than automatic.
Remember even with an automatic system your looking at 10-30 cycles minimum
before transfer usually much longer. Really expensive to get any faster.
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