Elk-624 Heat Question

[Sacedog]

So my alarm would not arm today, saying that a zone was violated. After doing some troubleshooting, I figured out that the powered contacts (motions, glass breaks) were only getting 6.5 volts from the Elk-624. The jumper was still set to 12V, and I have not touched my system for months.

I happened to have a spare Elk-624 sitting around, so I replaced it, and voila, I had 12V again. I armed the system and went to work. About 15 minutes later, I received a notification that my alarm had been activated. I disarmed it remotely, and continued on to work.

When I got home this evening, I went to check the voltage, and it was back to 6.5 volts. I then thought it might be the Elk TRG-1640, so I replaced that (I happened to have a spare of those too). Once again, I had 12V. While I was in the wiring closet, I was cleaning up, and after about 10 minutes, I noticed a "hot electrical smell". I went and looked in the can, and noticed that the Elk-624 was VERY hot. The cooling fin at the top of the unit was so hot, that when I licked my finger and touched it, it sizzled. I woudl not think that is normal, but I thought I would ask the question here.

Should the Elk-624 get that hot? If not, any ideas on why it is? Do I have a short somewhere? It seems odd that the 624 woudl get that hot...none of the wiring between the 624 and the 1640, the wiring from the 624 to the Elk (for the common ground only), or the wiring from the 624 to the PD9 was hot at all.

With the smell, I did not feel comfortable keeping the 624 powered on. I have a spare PD9 and battery that I could swap out, but I do not think they would help.

Thanks for any input.

 

[Sacedog]

Update. So, I started connecting from the beginning, to see if I could figure out where the issue is. I connected the 624 to the 1640, and powered it on...worked fine with no heat. I then connected the PD9 (but left the power switch on the PD( to off)...no heat. I then connected the battery, and the heat sync heated up fast. As soon as I unplugged the battery, it cooled back down.

Can a bad battery cause the 624 to overheat?

 

[thill]

Absolutely! Sounds like your battery may have developed a shorted cell or collapsed altogether causing it to draw as much charging current as the 624 is willing to supply. With the battery disconnected measure the voltage across its terminals. Your are likely going to read about 11.2 volts, maybe less. You need a new battery!

 

[Sandpiper]

Yes, it a shorted battery. I have seen them get so hot you can't touch them. Also, I've seen the cases buldge like it was about to pop. How old is your battery? Let me guess......4 or 5 years old?

 

[gatchel]

Happens all the time. I always write the date on batteries when I install them so I can tell at a glance whether or not to check it in the future.

 

[Del91574]

I agree, sounds like a definate battery issue, but I would remove the battery temporarily for testing, then verify the supply's output voltage and amperage to a known good (new) battery.

We get failures like these at least 2-3 times a week on one of our sites, with upwards of 2-300 power supplies. At least the battery didn't balloon or explode/split.