2. amps-preamps
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Nuisance tripping of AFCI circuit breaker by inrush of current when turning on amplifiers

I recently added an Accuphase power supply for my Accuphase mono blocks.  When I turn on the second mono block it trips the AFCI circuit breaker.  I had no trouble using the mono blocks with a Puritan Audio PSM 156 power conditioner, but it is passive.  The Accuphase PS-1250 is power regenerator with a huge toroidal transformer and a large mechanical on/off switch.  I imagine either the inrush of current from the PS-1250 + 2 mono blocks is too much for the AFCI breaker or their mechanical switches are creating arcs their algorithms do not recognize as normal.

I have a 10 year old Siemens 15 amp AFCI breaker, and my question is what best to replace it with?  I have read that AFCI breakers have improved considerably with less nuisance tripping, and the first step would be to use a current model as a replacement.  But is there a better solution?

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.

An electrician coming over at the end of the week, but I thought I would ask here as this must be an issue many audio hobbyists have encountered with AFCI breakers.

toronto416
erik_squires
16,406 posts
 

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

erik_squires
16,406 posts
 

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

oldelectricalinspector
10 posts
 

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.

toronto416 OP
258 posts
 

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.

randymaqp
12 posts
 

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. 
 

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