2. amps-preamps
  3. 193049-343

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
16,460 posts
 

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. 

toronto416 OP
267 posts
 

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!  

immatthewj
2,531 posts
 

 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.

 

erik_squires
16,460 posts
 

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.

toronto416 OP
267 posts
 

Thank you Erik - sage advice.

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