sundance-communications.com/forum Forums Wiring - Telecom Carriers - Trunks & Services Security, Alarms and Paging Bogen amp keeps tripping reset

This customer has had a paging system in place for many, many years. Some of the horns I installed, some by others (and they used a different speaker). I replaced the Bogen TPU60 5 years ago, because it had quit working after the previous 2 decades. The company plays background music through the system, and overhead pages when needed.

During the last couple of weeks, the amp has tripped it's built-in reset breaker. By the time I get there, I can't tell if the amp was hot or not. They claim no one has done any wiring or added any speakers. Resetting the reset breaker and everything works for a few days or a week, until it trips again.

I don't have an impedance meter, nor know how to use one. The wiring is old and mostly in a moist greenhouse environment. It splits off here and there a couple of places. It will be a nightmare to trace out and test. But what am I looking for? Reading each leg with an ohmmeter for shorts, high opens, ???

I'm thinking a bad horn or corroded wiring/connection?

Thanks for any direction.
Jim

An impedance meter is really the way to go. The Tpu 60 is a 60 watt amp you said they have horn speakers are they SPT 15's or something similar? Is it possible someone upped the wattage draw on the speakers? I've seen customers up the Spt 15's to the max of 15 watts is that possible? Does it trip after they make a page or just randomly shuts down? Are you wired for 25 or 70 volts?

If you know how to use a DMM, you know how to use an impedance meter. Without the impedance meter and a ground fault check, you can't eliminate the amplifier itself as the problem. Yes you will be looking for short circuits, ground faults, and overloaded lines (although this requires the impedance meter). Is there any hum or noise on the BGM source?

I vaguely remember, back in the K-Mart days, we used to find that some rogue employee would think they knew how to install speakers. Two wires, right? Or, worse, the black tape instead of speaker nuts would come loose and ground itself to the ceiling grid.

As the others have said, an ANALOG impedance meter is a nice tool to own. Turning up the volume (a Pyle PCM60 runs less than $100 on the secondary market or you could drive to Ohio and take an amp or two off my shelf). The problem is that you want to equip yourself with all the tools before you go to the job, or be very close to the site. Without that, look for corrosion in your moist environment and try to cut the load in half. Once you lift the speakers from the grid, you can meter them to ground and look for low resistance faults to ground on the legs you split off. You may find an odd resistance reading that doesn't match the others. Or, you'll probably find that bad boy in the middle of your string :-)

Good luck.

BTW the new amps actually have Bluetooth receivers and MP3 inputs for BGM and MOH.

Carl

I really doubt that an output short or other lesser problem would cause the circuit breaker to trip. That amplifier has electronic protection for that. Considering that the amp probably isn't used to its full 60W capacity with playing background music and probably not even during a page anyway, a short would only result is a loss of audio.

The circuit breaker is in series with the like AC line cord to protect against major problems like power transformer failure, output transistor failure, etc. So, my thoughts are that the circuit breaker itself is defective or there is some intermittent problem with the amp.

Time for a new amp unless you are competent to try replacing the circuit breaker.

-Hal

I agree with Hal, especially if the breaker is an arc fault breaker.

No Bill, it's the breaker on the amp that keeps the magic smoke from escaping.

-Hal

Right, Hal. Little red reset button.

If it's regular solder pads, I can handle that, provided I can find the correct replacement part.

If it's the new surfacemount solder, I'm sol.

Jim

Sorry about that, guess reading isn't my best subject. I still hate arc fault breakers.

No problem, Bill.
FWIW, I'm not a fan of arc fault either, but a necessary evil.

Nahh, that will never be surface mount. Likely wires on it. Should be readily available, should be a name on it. Manual says 1.6A I think for the 60W amp.



Not as much as I do. One of the biggest frauds. Never been proven to have saved one life yet alone actually worked. Only thing they do is cause problems and make money for the manufacturers. Now they are expanding the use of ground fault (GFCI) for no real reason except to make money.

-Hal

Me too. AFCI =Nothing but trouble

Sam

I recall about 45 years ago while working for Executone going to a service call at a car dealership with low volume on the paging system. I asked if anything was done with the system recently. Fortunately a guy in the service dept. admitted he added a speaker from car radio recently so they could hear the system better in their office. You all probably have an idea what I found - an 8 ohm speaker wired directly. It was above an intact ceiling tile with a pillow wrapped around it because it was so loud.

That was my first thought when I read this thread, only because I've seen this in the wild as well. If this is what your problem actually is, the impedance meter would have shown that in the first few minutes of troubleshooting. Anyone that does a lot of work with amps and PA systems owes it to themselves to get that meter.

The very second you disconnect that 8 ohm speaker, the load will stabilize and the volume coming out of the other speakers will be enough to wake your neighbors dog.

There is a one second fix for that. Simply disconnect the speaker wires from the rear of the amp and connect them to 120V with something like a line cord and clip leads. In less than one second any speakers without transformers will be destroyed. Those with transformers will be fine. Might want to warn your customer before you do it to cover their ears.

-Hal