On 11/22/2013 6:09 AM, wrote:
On Friday, November 22, 2013 1:35:28 AM UTC-5, Danny D'Amico wrote:
Dead alarm system troubleshooting advice requested ...

http://farm6.staticflickr.com/5540/1...fcb528ab_o.gif



Yesterday, I had been messing with the main breakers, and accidentally

shut the main 200A breaker without turning off the power generator switch;

so the Generac kicked in; and I heard the alarm system in the garage

vehemently complaining with persistent loud beeps.



I immediately reset everything, and I thought it was all ok.



Then, today, the alarm system sounded three loud long beeps, and

went totally dead.

http://farm6.staticflickr.com/5522/1...e48ee609_o.gif



Troubleshooting with my Fluke after removing the alarm system external

wires shows the external ELK-TRG21640 16.5VAC, 45VA power-supply

transformer plugged into an outlet has an open secondary, and when

plugged into an extension cord, there is no voltage from any of the

three screws on the secondary windings:

http://farm6.staticflickr.com/5527/1...d64103f6_o.gif



If I thought it was that simple, I'd just replace the transformer;

but I wondered why the backup battery didn't run the alarm system.

Testing the 12V 5AH battery out of the alarm system shows it's 13.5

volts DC (no load open circuit voltage), which, at least seems OK

(I don't know how to load it though):

http://farm4.staticflickr.com/3731/1...d9f59f77_o.gif



So, two things must be wrong:

1. The ELK AC transformer secondary opened up suddenly

2. Maybe the power supply inside the alarm system box went bad suddenly

http://farm4.staticflickr.com/3751/1...ff0ca903_o.gif



Do you think shutting the breaker without turning off the generator

could have blown the alarm system?



It shouldn't, but you'll never know if your experimentation
somehow caused it or if it was just a coincidence. There is no
question that home generators of various types have been known to
screw up some electronic equipment at times.



Any other troubleshooting suggestions?


I assume you checked for any low voltage fuses?

Transformers often have thermal fuses inside them.
But the ones I've replaced were in the primary.
And since you confirmed secondary, probably not your problem.
Might be worth a look tho.