"Danny D'Amico" wrote in message
news
On Tue, 26 Nov 2013 01:33:21 -0500, tm wrote:

If someone mixed up that wiring, it could present a short circuit
to the power supply and battery.

The alarm has been working for years, so, I'm pretty sure the wires
didn't all of a sudden get changed.

The good news is that the new transformer arrived today.

However, the voltage output wasn't at all what I had expected from a
16.5VAC transformer secondary.
http://farm6.staticflickr.com/5532/1...7612e531_o.gif

I measured:
a) 20 VAC across the secondary
b) 3.54 VAC across on side of the secondary to ground
c) 0.98VAC across the other side of the secondary to ground

Huh?


That's normal. The secondary winding is floating. What voltage do you see
across the aux terminals (DC)?

Is a) above with the transformer connected to the alarm board?

Get a fuse in line with the secondary to save the transformer in case
something is shorted. You don't want to damage the new transformer. I would
use a fuse equal to the secondary current rating marked on the transformer.