CHEAP, SAFE generator xfer switch? - Page 3

  Not necessarily - but remember you are in the UK where there are
only a few main circuit breakers or fuses and the house is wired in a
240V 1-Ph "ring main" system with heavier wire.  And the houses would
graciously be called "tiny" over here.

  The US wires houses with a main disconnect, and then separate
lighter duty 15A or 20A 120V branch circuits for 10 to 15 convenience
receptacles in each room or two.  When a branch breaker trips we only
lose one corner of the house, not everything.  And the Main trips only
when there are serious problems.

  There's usually a separate lighting circuit for every 4 or 5
overhead lights, and one for bathrooms and outside receptacles, and
two (or more) dedicated appliance circuits in the kitchen, and a
laundry circuit, and a 30A 240v clothes dryer circuit, and a furnace
circuit, and a 240V Air Conditioning Condensing Unit circuit, and a
30A 240V electric water heater circuit...

  If your generator can only handle a 20A load, you can always install
a sub-panel for just the essentials (lights, heat, water well pump,
telephone and computer power, refrigerator and freezer, and whatever
you deem a priority), and a smaller transfer switch to throw them onto
the generator either simply (manual transfer switch or mechanically
interlocked breakers) or automatically with a contactor style transfer
switch.

  You would want to use a somewhat heavier sub-panel, transfer switch
and "Normal" power feed line in the 60A range, so you can run
everything on the Emergency Sub-panel at once if need be, but you
don't need to throw the entire 200A house load over.  When you are on
the generator, you are either more thrifty with your power use or the
generator sends you a message by stalling...

    --<< Bruce >>--

-snip-


is that what happens?  i've wondered what happens if you turn on more stuff
than the generator can handle.  i was worried it would burn out the
generator.  what's the worst that can happen if you're running the maximum
watts your generator can handle and say your furnace blower motor starts up?
does it damage the generator?  does it damage the furnace blower motor or
any of the other devices that are running?  does a breaker trip, either on
the house panel or on the generator?  (sorry, i'm clueless.)

b.w.

In a normal proper setup, either the generator feed breaker (into the
panel, combined with an interlock on the main breaker in the lowest-cost
interlock setup) will trip, or the breaker built into the generator
itself will trip.

For some people, I suppose that a sub-panel with total loads never to
exceed the capacity of the generator might well be appropriate. For any
competent person, a 30 amp generator feed into a 200 amp panel (with
proper interlock, always!) is just fine - you turn off the furnace
breaker before you turn on the well breaker - and once the well pump is
done filling the pressure tank, you turn off the well breaker, and if
it's cold, you turn the furnace breaker back on. The advantage is that
you can power any circuits you need, and do the install without major
rewiring, so long as the total power you turn on at any given time is
less than the power supplied by the generator.

--
Cats, coffee, chocolate...vices to live by

that's the way i was hoping to be able to do it, instead of having to wire
in a sub panel, and so i could turn on and turn off everything that's
presently plugged in in the house, but like one at a time, when and if
needed.
but that's it huh?  if i mess up and turn on too many loads it won't destroy
the device (computers too?) and it won't destroy the generator, just pop
some breakers.  that's reassuring to know.
i appreciate the discussion and whoever it was that posted the link to the
square D interlock, that one does look simplest, easiest and cheapest.

b.w.

On Sun, 13 Jan 2008 19:11:26 GMT, "William Wixon"


  Most generators I've dealt with will either sag the voltage and
buckle down to try and power the overload till either the motor load
gets up to speed or a breaker pops somewhere.  Or if the overload is
large enough it will just flat-out stall the engine.

  No permanent damage anywhere, unless of course you keep restarting
the generator immediately and trying to power up the same overloaded
circuits again and again...

  Then you could build up enough heat in the generator windings to
cook them, just like short-cycling an electric motor more than it's
duty cycle allows.

  But as long as you have the Utility line properly isolated, you are
free to power the whole house panel.  But you'll have to practice some
strict "Green Acres" style power rationing, you assign a number to
each load and if the total goes over 7 the breaker trips.  (Amazing
that Oliver found a system Lisa could understand, but he did.)

  And if you already have a 7 load running nicely and accidentally
slam another 6 on top the engine stalls.

     --<< Bruce >>--

Bruce L. Bergman wrote:

The danger is when you add a modest additional load ( a few extra
lights) without a big inrush current. The engine sags, the frequency
drops to 50 hz and the voltage to 100 volts. A lot of other equipment is
quite unhappy at that point.


Yep, engine sounds like it hit a wall.

Bruce L. Bergman wrote:


Apropos the "30A 240v clothes dryer circuit."
Every time I have visited California, there has always been talk of need for
additional power generation, supply etc.
Yet, if people were allowed to hang there washing out, what a saving that would
be. California has the ideal climate but seemingly continues to cut off its
nose to spite its face. :-)

Tom

wrote:


Hang your clothes out????  Whatever for?  We just washed them, we dont
want them dirty again.

Gunner

On Sun, 13 Jan 2008 04:26:25 -0800, with neither quill nor qualm,


Let's see, 2006 shows 34.5 million, so we add 20% for uncounted
illegals, bringing the pop to 41.4 mil. Figuring a shirt, pants, 2
socks (or a bra), and skivvies for each person per day, that gives us
the nice round sum of 207,000,000 articles of clothing per week. And
you want all these to go outside to dry at once?  What are you trying
to do, Tom?   Raise the humidity level by ten points on the poor,
suffering Californicators, Tom?



Heh heh heh. But they don't live in Daft, CA, Gunner. It's less dusty
nearly everywhere else. West BFE is the only other dusty/dirty place I
can think of which might compare.

                            ---
    Chaos, panic, and disorder--my work here is done.

Larry Jaques wrote:

would

That many changes of clothing a week? Methinks it's been a while
since you traveled on the Bart. :-)

On Mon, 14 Jan 2008 05:52:18 +1300, with neither quill nor qualm, Tom


 

I hadn't mentioned those idiots who fail to wear deodorant. They stink
20 minutes after a shower in (otherwise) clean clothes. That's one
reason I've never wanted to travel to Europe (or around the world.)
My sister clued me into that when she spent a month touring Europe
after picking up her brand new 1973 BLMC MGB-GT from the factory.
"French women with furry armpits and BO from everyone everywhere" is
how she described it.  'Taint romantic to me.

                            ---
    Chaos, panic, and disorder--my work here is done.

Larry Jaques wrote:

BUT BUT BUT All that Humidity ends up out there anyway, or does the
dryer vents get piped back to some place like Mississippi?? :-)
    ...lew...

Gunner wrote:

 >
I thought that only happened when it rained? :-)

Tom

  The smart people change all the heating appliances they can (space
heat, water heating, cooking) over to natural gas (mains supplied) and
save a LOT of money, or Propane or fuel oil (on-site tank) and save a
little, compared to making heat with electricity which costs a whole
lot more.

  With electricity you have to pay for the heat fuel used at the
powerplant, and all the fixed costs and efficiency losses in
generating the power and getting it to your house, where you rather
inefficiently turn it back into heat.  With gas, you only pay for the
heat itself.

  We've kind of gotten away from hanging out the wash - it takes way
too long if you are trying to crank through a week's worth of wash in
a reasonable period, is labor intensive, depends on good weather which
isn't a constant some places, and you end with birds perching on the
clothesline and <ahem> doing their thing...  And then you have to run
it through the wash all over again.

      --<< Bruce >>--

Bruce L. Bergman wrote:

But the operative word in the above is  { smart }  :-)


Well with only two of us (retired and semi-retired) it takes two loads
and the weather in Albuquerque is about 90% co-operative and in 18+
years only one bird stain. (poison the damn pigeons) :-)
    ...lew...

Tom wrote:

WHAT!!! You mean it's illegal to hang your wash out on a clothes line
in the kingdom of Californication.???  Thats a wild claim. I can't
believe it.
    ...lew...

No, most don't;  The field just quenches, and they stop generating --
even PM versions go into a state that could be considered "quenching";
they lose coupling, and just stop putting out.  (kinda like a woman after
the first year of marriage).



LLoyd

"Lloyd E. Sponenburgh" <lloydspinsidemindspring.com> wrote in message

is that permanent damage?  or is it that you turn off some loads and restart
the generator and the generator is ok, not damaged and starts generating
electricity again?
what's "PM versions"?

b.w.

On Mon, 14 Jan 2008 01:53:01 GMT, "William Wixon"


pre-menopausal

Gunner

A permanent magnet, rotating field unit can be harmed by long running
under that condition, but won't usually be.  A wound field type isn't
harmed at all by it.  It just loses field excitation, and stops
generating.

Remove most of the load, and they'll kick back to life.

LLoyd