Thought I'd post here as it's more of a general house thing. My desktop computer has been tripping the bedroom circuit breaker occasionally over the last few months. It appears to happen when there's a demand spike (like if I'm taxing the computer and turn on a second monitor). It's a 15amp circuit and it looks like an AFCI breaker (has a 'test' button on it with a big 'D').

From what I'm reading online it could possibly mean a failing breaker. I've got my desktop set up on a surge protector. I can't imagine I'm using more than 600-700 watts but I'm sure it could spike over 1000? I've never had this happen before at any other house or apartment. Is the AFCI just doing it's job and detecting an arc-fault and flipping the breaker?

As I'm renting I put in a maintenance ticket to check it out. Wanted to see if anyone had any thoughts here.

9/20/2015 3:29:00 PM

I have the same problem in my office. Once I put a battery backup on the system it stopped happening. The backup kicks in sometimes when the printer initially kicks on and then all is well.

9/20/2015 3:38:24 PM

Yeah I've read laser printers can spike over 1000 watts. I do have a small laser printer but standby is 4 watts on it and I've never been using it when the circuit has tripped.

Anyone have any good UPS recommendations?

9/20/2015 3:45:33 PM

After talking to an EE co-worker he thinks I'm just spiking over the 15 amp limit or tolerance of the AFCI and it's tripping. Downside to replacing with a 20 amp breaker?

9/21/2015 11:13:31 AM

what's the panel rated for and what's your breaker total on the panel? it's probably fine

also, surge protectors on GFCI circuits can trip the GFCI protect (but I can't remember why)

[Edited on September 21, 2015 at 11:43 AM. Reason : .]

9/21/2015 11:41:01 AM

I'm not an expert, but I don't think it's quite as simple as just replacing the breaker with a higher amperage one.

You need to verify the gauge wire used from the breaker to the outlet. Chances are, it's not a dedicated outlet either, so is likely daisy-chained. You'll probably want to verify that all wiring is the appropriate gauge, otherwise it's a fire hazard, and against code. It may still be against code regardless. Not sure.

I'd verify with a certified electrician before I did anything.

9/21/2015 11:42:20 AM

Quote :

"also, surge protectors on GFCI circuits can trip the GFCI protect (but I can't remember why)"

So it's not a GFCI (on the actual outlet) it's an AFCI (I think). I think they have similar functionality though.

Another question. Why are only two of the breakers on the panel AFCI and not others? The living room and many other circuits are regular whereas the bedroom is AFCI. I'm thinking they're either slowly replacing them with AFCI breakers or there's a reason they're AFCI. Usually they would go in a bathroom or kitchen (where an ARC fault is more likely) but those are just regular 20 amp breakers.

Maybe it's simply a matter of replacing it with a regular 15 amp breaker instead of an AFCI unit. I've read they can malfunction and trip when they're not supposed to.

Quote :

"You need to verify the gauge wire used from the breaker to the outlet. Chances are, it's not a dedicated outlet either, so is likely daisy-chained. You'll probably want to verify that all wiring is the appropriate gauge, otherwise it's a fire hazard, and against code. It may still be against code regardless. Not sure."

Thanks yes this all makes sense. The building was built in 2009 but it should still all be verified before making any chances.

Quote :

"I'd verify with a certified electrician before I did anything."

Yes it's a rental so I'm not doing anything. The electrician is probably giving me a call today to discuss.

--Doing some reading afci breakers are now required by code for bedrooms. Possibly other rooms now too.

I'm wondering if I try it in the living room it'll work because it's not on a afci.

[Edited on September 21, 2015 at 12:20 PM. Reason : s]

9/21/2015 12:00:50 PM

Quote :

"The living room and many other circuits are regular whereas the bedroom is AFCI. I'm thinking they're either slowly replacing them with AFCI breakers or there's a reason they're AFCI. Usually they would go in a bathroom or kitchen (where an ARC fault is more likely) but those are just regular 20 amp breakers. "

probably en suite bathrooms on the same circuits

9/21/2015 12:46:03 PM

The bathrooms are on separate 20amp breakers. I found online that AFCI breakers are required by code in bedrooms now. Maybe due to ceiling fans? Hair dryers? Not sure. There isn't AFCI breakers in the living room.

9/21/2015 1:06:10 PM

AFCI breakers suck. Had this exact problem in one of my apartments a few years back.

Is the breaker tripping or the AFCI blowing? Should be 2 different things. If its the breaker: replace it. If its AFCI, get an electrician out there ASAP as you may have a fire hazard and its doing its job.

They are required due to code, for electrical fires. Frayed wiring is the normal cause, and the arc from a short (that starts a fire) will trip it. I think they are trying to make them house-wide soon though.

9/21/2015 6:14:04 PM

How do I tell the difference? An AFCI just looks like a normal circuit breaker but with a test button. I guess I'll check next time it's flips. There's not a separate breaker.

The electrician came today. He's going to replace the breaker. I'm going to run an extension cord and try the surge protector on a different circuit in the living room and maybe swap surge protectors and see if it happens.

I can get it to happen when I either run a computer benchmark and max out the CPU and GPU or when I'm playing a game and turn on a second monitor. I assume both cause power spikes which are flipping the breaker.

9/21/2015 8:51:42 PM

AFCIs are required in bedrooms, hallways, and living rooms

[Edited on September 21, 2015 at 9:00 PM. Reason : relatively new addition to the NEC, though]

kitchens, baths, garages, basements, etc. require GFCIs. there is a difference.

GFCI can be accomplished by making the first outlet on the circuit a GFCI outlet, or just installing a GFCI breaker.

there are also combo AFCI/GFCI breakers.

or you can have a GFCI outlet on a AFCI breaker.

[Edited on September 21, 2015 at 9:05 PM. Reason : eventually they'll probably just make us install AFCI/GFCI combo breakers for every CKT]

9/21/2015 9:00:01 PM

Quote :

"AFCIs are required in bedrooms, hallways, and living rooms"

My complex was built in 2009 and there's no AFCI on the living rooms just the two bedrooms. There's GFCI's in the bathrooms though.

I'm reading all over that power surges can easily trip AFCI's so I'm leaning towards that. I mean I guess it could be bad wiring as well. How could we determine whether it's bad wiring or I'm simply maxing out the circuit? This faulty tripping is called "nuisance tripping" from what I'm reading but may still be caused by bad wiring. I'm on a surge protector is it possible it's my computer (besides pulling too much power)?

Once he replaces the circuit in a few days I'll see if it's still happening then continue to trouble shoot.

9/21/2015 9:10:02 PM

NEC is one thing. how well it actually gets enforced locally is another story.

could be that they already swapped the living room AFCI out for a standard breaker due to nuisance trips.

hell, plenty of DIY types install AFCIs until they pass inspection and then pull them out and return them and install standard breakers. AFCIs are like $50 and a regular breaker is <$5.

9/21/2015 9:16:35 PM