Amp tripping circuit breaker.

Yes. Your breaker is failing. They use a magnetic principle and the more they break, the easier they break. Replace it- see how that goes.

The AFCI part can trip based on modest ground currents. It is cheap and easy to replace, and worth trying.

If it still happens, I suspect you have a ground loop you are not aware of, which will trip an AFCI breaker.

Best,
Erik

Replace breaker they are known to fail.

One thing I forgot to mention - the reason I suspected the amp is because it’s own protection was tripping earlier in the summer, often immediately when powering from a cold start.  It ended up going away.  Only thing I can think of that made the problem go away, was I went from having the thermostat set at 76 to 72, which definitely reduced the indoor humidity.

Unknown if it matters if amp is on or not.

Yes it matters.

https://www.youtube.com/watch?v=ihforRdL-TU

magneplanman OP1 posts

12-10-2019 11:44am

One thing I forgot to mention - the reason I suspected the amp is because it’s own protection was tripping earlier in the summer, often immediately when powering from a cold start. It ended up going away. Only thing I can think of that made the problem go away, was I went from having the thermostat set at 76 to 72, which definitely reduced the indoor humidity.

Now that’s more info. The breaker on the rear panel is a magnetic type breaker. If it was tripping that could indicate either a short circuit or very high inrush current when the Amp is first turned on. Repeated tripping and you repeatedly resetting it was a bad idea. You may have caused the contacts of the breaker to weld, fuse, themselves together preventing the breaker from tripping open. It looks from what I can tell the breaker is a 15 amp.

Now you are causing a 20 amp breaker to trip from a possible short circuit or high inrush current. I suggest you have the Amp checked out.

Repeatedly resetting a circuit breaker in an electrical panel can be dangerous. I know of an instance where a 20 amp Square D QO circuit breaker exploded and burned the fingers and hand of an electrician.


.

The AFCI part can trip based on modest ground currents.

AFCI is Arc Fault. GFCI is Ground Fault. They are completely different. One is an arc that can be a fire hazard. The other is more a nuisance (when it trips) than a risk.

Long story short, the breaker only trips when the amp is plugged in, with statistical certainty.  Unknown if it matters if amp is on or not.

If it happens with the amp plugged in and turned off there is a statistical certainty its not the amp.

 the reason I suspected the amp is because it’s own protection was tripping earlier in the summer, often immediately when powering from a cold start.

And yet this did not trip the breaker. This is what we call a "clue".

It ended up going away.

So the amp was a Walker?

Only thing I can think of that made the problem go away, was I went from having the thermostat set at 76 to 72, which definitely reduced the indoor humidity.

Fascinating.

Call in an electrician. The breaker may be doing its job, that is, there could be an arc fault somewhere in the circuit. Did you nail anything to a wall over that time period?

I had a breaker fail once and (after shutting off the main power switch) I simply removed it, took it to Home Depot to make sure I bought the right replacement...installed it in a few minutes. Done.

@OP

By chance is the electrical panel/ AFCI breaker in the panel a Square D type? By chance does it have a white test push button? If so it is a CAFI AFCI and you can test whether the breaker is tripping on over load or short circuit,  or,  if it is tripping on arc fault.

Video
https://www.youtube.com/watch?v=Rw8exWpipJY

Here is another Link for a square D CAFI AFCI breaker. Click on the first video on the left hand side of the page.
https://www.homedepot.com/p/Square-D-Homeline-20-Amp-Single-Pole-Combination-Arc-Fault-Circuit-Break...


*Do not attempt to change out the breaker yourself... Hire an electrician.

Did you nail anything to a wall over that time period?

Do not attempt to hammer anything into a wall. Hire a carpenter.

Thanks everyone, lots of good education material.  I think I will replace both the amp and the breaker.

If it happens with the amp plugged in and turned off there is a statistical certainty its not the amp

so far that hasn’t happened, since I’ve kept a log

And yet this did not trip the breaker. This is what we call a "clue".

Are you implying that the amp tripping is an independent issue from the breaker?  maybe I’m not following.

I am a certified electrician. And I believe part of the problem is the AFCI breaker since it is known to be a common problem with them and GFCI types. Also confirm if you are using a 29 amp breaker with at least 12 awg. Wire otherwise you are overloading the circuit with your rack setup. Just because the breaker says 20 doesn't mean the romex in the wall is suitable for such a load. 

I would find out what the amperage is under load with. Conventional amprobe  at the panel. And if you are exceeding 16 amps then you are using more than the breaker can handle for long term use. 

I would recommend a dedicated circuit with at least 12awg  10 would be best. and have the electrician or yourself balance the loads between your 2 legs at the panel. By moving some wires around to come up with the most balanced load on your hot legs. 

I have seen tripping on breakers from loose connections both in j boxes and receptacles. And in some cases the wires can overheat and melt before the breakers actually trip.

Hope this helps.
 

I meant 20 amp not 29 amp breaker.

Yes it’s 20 amp wiring.

Trouble shooting 101...replace the least expensive item first.  Replace the breaker and see what happens. 

NEVER change 2 things at once.

Ground at wall outlet?

I can understand lost confidence in the amp, but, the advice to replace the breaker first is the best.

If electrician does it, he/she can also test ground, at the panel and at the wall outlet.

That will tell you whether it was the ground, breaker, or the amp.

IF, after replacing breaker, ground confirmed, with amp connected, turned off, new breaker trips, curious indeed. Test that before electrician leaves.

Do you have any other equip you could substitute for amp, to see if problem goes away? 

IOW, think like an electrician rather than as an audiophile.

New amp after circuit confirmation? Always fun. Keep in mind, you won't be able to sell the existing amp unless you confirm it was the breaker, not the amp. Another reason not to change two things at once.

I had the same thing happen, but only with a particular high current amp. Other more modest amps would not trip the breaker. But if I plugged the high current amp in any other circuit it would not trip a breaker.

I haven't done so yet, but replacing the breaker is on my to do list.

magneplanman OP4 posts

12-10-2019
11:44am

One thing I forgot to mention - the reason I suspected the amp is because it’s own protection was tripping earlier in the summer, often immediately when powering from a cold start. It ended up going away. Only thing I can think of that made the problem go away, was I went from having the thermostat set at 76 to 72, which definitely reduced the indoor humidity.

Repeat:

One thing I forgot to mention - the reason I suspected the amp is because it’s own protection was tripping earlier in the summer, often immediately when powering from a cold start.

@ magneplanman

I assume you are referring to the 15 amp "Master Power" On-Off/circuit breaker on the rear panel of the amp. Is that correct? The "Master Power" circuit breaker was tripping immediately when powering from a cold start?

See page 6 of manual.

E. MASTER POWER:The Master Power switch is used to apply or remove power to the amplifier. By contrast, the Power switch on the front panel is used to switch the amplifier between standby mode and full power on.

See page 10.

MAIN CIRCUIT BREAKER: The Master Power switch on the rear panel doubles as a circuit breaker. If the circuit breaker trips into the off position, try flipping it back on. If it immediately trips back off, unplug the amplifier from the power source and have it serviced.

https://downloads.monoprice.com/files/manuals/14566_Manual_160414.pdf

One thing I forgot to mention - the reason I suspected the amp is because it’s own protection was tripping earlier in the summer, often immediately when powering from a cold start. It ended up going away.

"It ended up going away. "

As in the breaker no longer works?


Please respond if the above circuit breaker was the device tripping immediately on a cold start up of the amp.I also would like you to move the "Main Circuit Breaker" (rear panel on the amp) to the off (O) position. Verify in the off position the unit is dead, no power, lights, ect...

As for the dedicated branch circuit GFCI breaker that feeds the amp. Going from what you posted it was/is high inrush current draw from the amp that was causing the 15 amp breaker at the amp to trip open. Assumption, the breaker no longer works. The GFCI breaker was next in line to protect the branch circuit wiring. (You never mentioned what manufacturer the electrical panel/breaker is. It would be nice to know) Note. It would be safe to say it is the Thermal-magnetic section of the AFCI breaker that is causing the breaker to trip open. The high inrush current draw of the amp is causing the breaker to trip open.

Is the AFCI breaker weaker now after several tripping events than when it was when it first tripped opened? Probably. Will installing a new breaker solve your tripping problem? For a while. Band-aid repair.

.

jetter1,477 posts   

12-11-2019  
 8:03am  

I had the same thing happen, but only with a particular high current amp. Other more modest amps would not trip the breaker. But if I plugged the high current amp in any other circuit it would not trip a breaker.

I haven’t done so yet, but replacing the breaker is on my to do list.

@jetter

In your case you may want to see if the manufacturer of your electrical panel makes a High Magnetic, HM, branch circuit breaker.


What is a HM type breaker? What does it do? It allows a greater lag time for inrush current before it will trip.

Example of:

Square D

Standard QO115 and QO120 circuit breakers are manufactured to have a magnetic trip point at approximately 8x to 10x the breaker rating. There are some applications, however, in which a load has an inrush current high enough to cause these standard circuit breakers to trip. Examples of these loads include area lighting for athletic fields, parking lots, or outdoor signs. To allow the high inrush current without tripping the circuit breaker, a high magnetic breaker should be used. These high magnetic breakers breakers have a magnetic trip point set much higher than the standard circuit breakers. They can be identified by the HM suffix on the catalog number (QO115HM). Current production HM breakers are also identified with a "High Magnetic" label on the side of the breaker (see photo).
NOTE: The above explanation comparing the standard breaker to the high magnetic breaker applies to 1-pole, 15A and 20A, QO, QOB, QOU, HOM and CHOM breakers only. Other ampere 1p breakers, and all 2-pole and 3-pole versions are already high magnetic as standard. (Breakers with suffix GFI, AFI, CAFI, or DF are not available as high magnetic).

https://www.se.com/us/en/faqs/FA96714/


.

Thanks for the information jea48, live and learn.  I will talk to my electrician about it.  I know changing a breaker is a simple thing, but I would rather not mess around with it myself.

I do know that when a friend was going to replace the breaker in question, for some reason it was not one of cheaper ones that GE makes.  It had something about it that made it a $50+/- variant.

EDIT:

jea483,211 posts  

12-11-2019   
 9:03am




As for the dedicated branch circuit GFCI breaker that feeds the amp. Going from what you posted it was/is high inrush current draw from the amp that was causing the 15 amp breaker at the amp to trip open. Assumption, the breaker no longer works. The GFCI breaker was next in line to protect the branch circuit wiring. (You never mentioned what manufacturer the electrical panel/breaker is. It would be nice to know) Note. It would be safe to say it is the Thermal-magnetic section of the AFCI breaker that is causing the breaker to trip open. The high inrush current draw of the amp is causing the breaker to trip open.

Correction:


As for the dedicated branch circuit GFCI breaker that feeds the amp.
Should read:
As for the dedicated branch circuit AFCI breaker that feeds the amp.

The GFCI breaker was next in line to protect the branch circuit wiring.
Should read:
The AFCI breaker was next in line to protect the branch circuit wiring.