Nuisance tripping of AFCI circuit breaker by inrush of current when turning on amplifiers

I would definitely start with a second generation Siemens CAFCI breaker.

Im not sure about your situation butI have 20 Siemens CAFCI breakers, all upgrades fron non AFCI and never had a nuisance trip.

The electrician probably can't help you.  What you really need is a soft start on your power supply.  Many large power supplies charge the system through an inductor to limit inrush current and then switch to a straight wire to run the system.  You must not have one but you might check your user manual to make sure that you don't have one and just have it turned off.  You would probably know.

First thing I would do is replace the breaker like you are suggesting.

@erik_squires will show up soon and he is expert in this subject so wait for his recommendation.

Jerry

Also, check with the manufacturer.  With AFCI breakers now required in all residential circuits this should be something they are aware of.

Ps, the online forums complaining about first gen. AFCI tripping have settled down quite a bit with the second generation CAFCI versions.

Last, really, ive seen power conditioners with very large toroids trip breakers, had nothing to do with AFCI

AFCI breakers react to arc signatures. The circuit should be gone through and all connections should be tightened. It’s possible that there is micro arcing somewhere. I have seen this resolve nuisance tripping before.

Many thanks for all the expert advice - much appreciated!

I think Accuphase amps have soft start - not sure about the power supply - but they all have large mechanical of/off switches that could be arcing.

I will ask the electrician to tighten the connections.

I’m not familiar with your amps or their power requirements, but this was my situation:

I have 5 year old Eaton 20 amp CH type AFI breakers and one started tripping after I got my new McIntosh MC611 amplifiers. The dealer took the amps back and thoroughly tested them and, of course, didn’t find any problems,  I called an electrician who replaced the breaker with a new one, and the problem went away.  He told me that those breakers had a recall on them so he’s coming back to replace them under warranty. 
 

I’m not competent to advise on Canadian electrical requirements, but there is something in how you describe the thing that leaves me puzzled.

I assume you have plugged the two amps into the PS-1250, but you are still switching them on manually and independently. You switch the PS-1250 on, then the monoblocks sequentially, and it’s on the second one that you get the AFCI tripping. If that’s not correct, ignore what follows.

**************

This, to my mind, rules out the PS-1250: if it was the inrush current into that, it would trip when you switch it on, not when you add a load to it.

I suspect that points to the second amp causing some micro-arcing that was previously snubbed by your passive conditioner (they work either way...), but not by the PS-1250.

Replacing the AFCI with a more advanced one may help avoid the tripping, but I would check the amp power switch’s health too... before it gets damaged (or damage progresses to a no-power-on situation). That is particularly the case if it’s always the same amp that causes the issue.

@Dievi67  good suggestion.  This can be tested by turning the amps on in the opposite order and seeing if it is still the second one that trips or if it is always the same amp that trips the breaker.

Jerry

Is a convenience outlet fed by a 15 amp breaker up to code in Canada? That aside, I would try another outlet on a different breaker to see if the probem follows there. Preferably an outlet on a 20 amp breaker with AFCI. Hope this helps. Also, it would be interesting to know what size wire is feeding that outlet. 

I almost firgot.  Afci, cafci and gfci breakers include diagnostic LEDs.  If they arent on you have a plain old overcurrent trip.

If it really is an AFCI tripping, consider swapping out power cords as well as changing the order of amplifier starts.

I do repeat though, first generation AFCI breakers (1999 ish) were more jittery than the second generation CAFCI breakers. 

Some good suggestions - thank you!

I did try changing the sequence of turning on the amps - and bingo - regardless of which one I turn on first, all is well until I turn on the second amp - this trips the breaker.  So it appears to be a load issue and not the amp switches.  Hopefully a new breaker will do the trick - 20 amp vs. 15 amp.

Trying a different circuit would entail moving the power supply (93 lbs) and the mono blocks (101.5 lbs each) to another room - 300 lbs of gear!  

 Hopefully a new breaker will do the trick - 20 amp vs. 15 amp.

I may have missed it if you mentioned it because my eyesight is bad and getting worse every day, but I assume that the circuit is wired with at least 12 gauge if not larger?  If not, you would not want to use a 20A breaker.  I was only checking because I was thinking that this may have been the reason you currently have a 15A breaker in there now.

Square D makes 'High Magnetic' AFCI breakers that are less prone to nuisance tripping, but I don't know if they would even fit in my panel.  I'm not sure if Siemens makes a similar product.

As far as this goes, I am not an electrician, but it has always been my understanding that using a breaker that is not the same brand as your panel can cause a homeowner's insurance company not to pay out in event of a fire.

The only circumstance under which you should change the breaker amp rating to 20 A is if you have 12 gauge wiring already.

Do not increase the amp size unless you are sure or rewire.

Thank you Erik - sage advice.

Since you said you were having an electrician come to look things over, you could ask him what he'd charge to put a separate  circuit (or circuits) using 12 or 10 gauge wire in where you want your system to live (assuming you don't want to do it yourself).  .   

Thank you Matthew - that is a good suggestion.  It is not something I would be able to do myself.

It's not that bad a job, but for me it was time consuming both times I did it, and the second time I dropped some new circuits down to a new location (a couple of years ago) I had learned a lot more than the first time I did it about 30 years ago, so I went back to those original circuits I dropped in to tidy some stuff up, and some of the stuff I had done looked almost scary to me the second time around.  So anyway, I don't think it would be cheap to get an electrician to drop a new circuit in, but the benefit your system might derive from it's own dedicated circuit(s) might be worth it to you.

Anyway, what I meant to say but I forgot, was that I am pretty sure that putting a 20A breaker on a circuit made of wire smaller than 12 gauge would be another  reason that a homeowners company could use to void your policy in the event of a catastrophe.  

If you are going to rewire separate dedicated circuits, please read this from The Absolute Sound. It came out this month and is by Vince Galbo of Galbo Design and input from MSB Technology.  

HIs best advice is: I repeat: Be smart here, give this paper to a licensed electrician and let him do the work.

All the best,    
Nonoise

1- ARC-fault Circuit Breakers (and GFCI) age.

2- AFCI CB’s are often garbage out of the box.

3- replace yours with a NORMAL breaker, NON GF/AF if nowhere near water.

we JUST a month ago  passed final electrical inspection. the day before, the team of electricians finishing up pulled SIX  of the new/improved NEC-tech weenie designed “saving lives” models as, out of the box, they were failing, tripping repeatedly.

Interestingly, a month earlier, ONE of them tripped randomly and it happened to power our home alarm system. So for four weeks we had NO fire/flood/break-in protection. once the battery backup/UPS ran down.

But, NEC tech weenies say “mUh SaFEtee! dErP!”

The MINUTE after the electrician left, new Certificate of Occupancy sticker on the breaker box, I replaced THAT breaker with a NORMAL, NON GF/AF CB.

It’s your house, your decision. Spend another $100 for another AFCI type CB or more. Pays your money, takes your chances.

If you want to further test your equipment on another outlet, you don't have to drag all of your stuff to the other outlet. An extension cord will do.

Could be: 

1. Touchy old AFCI breaker - install new one (same brand), easiest fix

2. AFCIs need neutrals wired back to the same breaker the hot came from. If not, they'll trip all the time. But if a big vacuum cleaner or power tool doesn't trip it, it's likely wired ok.

3. Overcurrent - you need a 20A circuit installed.

Let us know what the electrician says. Good luck! 

Electrician failed to show today, so I contacted another company.  A frustrating delay...

I know electricians are in demand, so I need to be patient.  

Hi Toronto 416,

please keep us updated, I’m really interested in how this turns out

rich

@toronto416 , @devinplombier made a very good suggestion!

Breakers break more easily the more they break. Eventually they are breaking at far lower currents than they are rated.

So you might just try replacing the breaker with a new one and problem solved.

Here is an update - the electrician was just here.  With a little troubleshooting he determined it was not my audio system at fault, but a faulty AFCI breaker.

The Accuphase PS-1250 power supply with 2 mono blocks plugged into it draws 7.5 amps.

The pre-amp and cdp are plugged into another Accuphase PS-530 power supply which draws only 0.2 amps.

Total draw of the audio system with music playing is 7.7 amps.

Replacing the faulty AFCI breaker solved the tripping issue.  

I have a 15 amp circuit with 12 guage wire.

Good to read, @toronto416 !  Time to rock out!

(And since you have 12 gauge wire, if you want to, you can put in a 20A breaker.)