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Alarm system transformer + power supply (would both go bad atonce?)
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The Daring Dufas[_8_]
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Alarm system transformer + power supply (would both go bad atonce?)
On 11/22/2013 10:12 AM, Tony Hwang wrote:
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?
Hi,
Just start with replacing the x-former and battery. I strongly suspect
battery is no good. When you check the voltage did you remove a lead
from battery terminal since you mentioned no load voltage.
Your battery is not holding charge so when x-former quit, it couldn't
supply the necessary juice.
Look at the picture of the module between the battery and power
terminals. It's a battery saver module designed to keep the battery from
being completely discharged. Look closely at the blue electrolytic
capacitor on the module circuit board. It looks swollen and electrolytic
capacitors can dry out and become a short circuit, especially if they're
22 years old. ^_^
TDD
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