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

Showing 7 responses by toronto416

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.

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!  

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

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.  

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.