On Tue, 11 Jun 2013 09:06:51 -0400, "Eisboch" wrote:



"John H" wrote in message
.. .


We've only one time had an electrical issue at a campground. We blew
the 30 amp circuit breaker at
the electric post. All was well with the air, coffeepot, water heater,
fireplace (which my wife
leaves on for looks way too much), lights, refrigerator, etc, and then
my wife plugged in her hair
dryer - oh, and I think I had something in the microwave. The trailer
circuit breaker handled the
load, but we were plugged into 30 amps outside. That one didn't.

Don't know if the Autoformer would have helped then or not. How does
it boost the voltage?

John H.

-------------------------------------------------

No, the Autoformer wouldn't help in that situation. You simply
overloaded the circuit breaker and it tripped, just like it's supposed
to. You are probably going to ask why the main 30 amp breaker in your
trailer didn't trip also. It's because they are basically in series
and the one with the most sensitive trip setting trips first. In your
case it was the outside breaker. Once it tripped, no power is on your
trailer breaker, so it didn't trip.

That is not the purpose of an Autoformer. Here's a simple example
of it's purpose. I am going to ignore pertinent AC electrical load
laws regarding voltage leads current, etc.

Assume your AC unit compressor kicks on but your supply voltage
(commercial power) has drooped to something less than the typical
118 - 120 vac.
It still takes the same amount of power (watts) for the compressor to
turn on without it straining. Power is voltage times current. If
the voltage drops, current draw must go up to produce the same power.
When you factor in the other "ignored" AC load issues, the result is
the compressor motor drawing excessive current which can burn up the
windings. The Autoformer prevents this by boosting the supplied
voltage.

An Autoformer is simply a type of buck/boost type transformer with a
logic circuit in it that determines the supplied voltage. If it drops
below a certain value (117 vac) it electrically connects the primary
of the transformer to windings that boost the output voltage by 10
percent. When supplied voltage exceeds 118 vac, it returns to the
normal windings automatically.



Thanks for the explanation. The trailer circuit breaker is 50 amps, which is one of the reasons I
was perplexed when everything blew.

Glad to see your comment about the Honda EU2000. That's next on the Christmas list - or maybe much
sooner.

John H.
--

Hope you're having a great day!