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Old July 18th 19, 04:11 PM posted to,
Jeff Liebermann Jeff Liebermann is offline
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First recorded activity by DIYBanter: Jul 2007
Posts: 3,968
Default How the heck does a typical home transfer switch work?

On Thu, 18 Jul 2019 05:01:27 -0000 (UTC), "Arlen G. Holder"

If that makes it work, then my problem is likely the "sensing" circuitry,
where this sticker explains all that sensing circuitry is hard coded, I

Methinks your first problem is finding the box that controls the
automagic transfer switch (which contains the sensing, timing, and
switching logic). Something like this:
"Automatic Transfer Switch Controller Tutorial"
It's probably inside the generator enclosure. Just look for another
rats nest of wires. The thresholds, timing, interlock, etc settings
are usually adjustable.

I have two guesses:

1. The +12VDC that runs the relay is probably missing because the
starter battery in the generator is dead, or the fuse that protects it
is blown. That might explain the missing fuses. It might also be
that State Electric took one look at the mess and ran away. There
might be some lower voltage coming from the charger trying to charge a
dead (shorted) cell.

2. Every controller I've seen has a self-test and/or test-run
feature. You should be able to test the transfer switch with the
test-run button instead of reworking the wiring.

Also, I have some suggestions:

1. Don't play with the transfer switch with the utility AC power
applied. The life you save may be your own. The undersized wires
feeding the transfer switch should go to a double breaker on the main
panel. Flip it open, check that there is now no AC on the contacts or
anywhere in the rats nest of wires, and then troubleshoot.

2. Draw as schematic diagram and label everything. If this were my
headache, that's the first thing I would do.

3. If you know a local electrician, who won't turn you in to the
county, have him look at the wiring and make some recommendations.

Jeff Liebermann
150 Felker St #D
Santa Cruz CA 95060
Skype: JeffLiebermann AE6KS 831-336-2558