Grassroots Motorsports

Register Log in to GRM
- Community

Birthdays
Recently on the Classic Motorsports forums

Subscribe get a full year for only $23.95 Sample Free Test Drive—no strings attached

Login to post Forums » Off-topic discussion » Bad Circuit Breaker Gut Check

Jan. 25, 2009 8:41 p.m. ignorant SuperDork

Home was built in 2005. I've been having trouble with the breaker for my master bedroom and bathroom. A month ago we started using a warm mist humidifier(it boils water) and it would sometimes trip the breaker. It is a Type QO GCFI Square D if that makes a difference. I would reset the breaker and it would be OK. It then got to the point where, If using the humidifier it would not reset or trip immeadiately. I assumed it was the humidifier(not actually having the time to test anything) and threw it away.

Fast forward to tonight, the breaker blew and will not reset unless no load is on the circuit. Any load and she blows. Even a single bulb 11watt CFL. I pulled all load on circuit, reset and then tried putting load on to see if a device was causing it. So.. I pulled the cover and checked the connections. They are tight.

So I'm guessing bad breaker. What you think?

I've done some wiring in our plant, nothing terrible but mostly low voltage. I'm going to replace the breaker tomorrow.
Jan. 25, 2009 8:48 p.m. rustyvw HalfDork

I would pull the plugs on tht circuit and see if anything has worked loose. You may have a wire that is not making good contact.
Jan. 25, 2009 8:53 p.m. ignorant SuperDork

I did pull everything off of the circuit, no load, and then tried to add one load back.. but even for a small lamp it tripped.
Jan. 25, 2009 9:04 p.m. AngryCorvair Dork

ignorant wrote:

I did pull everything off of the circuit, no load, and then tried to add one load back.. but even for a small lamp it tripped.

did you try it on several different receptacles on that circuit?
Jan. 25, 2009 9:18 p.m. Dr. Hess SuperDork

Breakers go bad. They are just a strip of metal that heats up and changes shape. Get another one of the same amp rating. Note though, that every single manufacturer makes their own flavor of breaker, so you have to get the same brand as you pull out or one that specifically will replace that. They change the location of the plug-in parts very slightly so you have to buy their brand replacement parts.
Jan. 25, 2009 9:21 p.m. ignorant SuperDork

AngryCorvair wrote:

ignorant wrote:

I did pull everything off of the circuit, no load, and then tried to add one load back.. but even for a small lamp it tripped.

did you try it on several different receptacles on that circuit?

Tried about 4 and 1 ceiling fan.
Jan. 26, 2009 6:29 a.m. ignorant SuperDork

buddy from work.. who was an electricians apprentice before deciding to become a mechanical engineer... (figure that out).. is coming over after work.. thanks for the help folks.
Jan. 26, 2009 7:02 a.m. Gearhead_42 HalfDork

ignorant wrote:

buddy from work.. who was an electricians apprentice before deciding to become a mechanical engineer... (figure that out).. is coming over after work.. thanks for the help folks.

Well, that's easiest I guess. I was going to suggest swapping that breaker to another ilghtly loaded circuit in the house, and see if it trips on that circuit. Conversely, swap a breaker from that circuit to your suspect circuit.

If the new circuit trips the old breaker, bad breaker. If the new breaker trips on the old circuit, start looking for dead rodents in your walls...
Jan. 26, 2009 9:46 a.m. fastEddie Dork

Breakers do have a relatively short life cycle, the more they trip the faster they wear out until they won't hold at all. Follow the good Dr.'s advice and buy a new one.

Not sure what the T&C's are but that breaker should have a Limited Lifetime Warranty - http://www.squared.com/us/products/motor_control.nsf/unid/DB9C2F2BDABA3AF485256C22...
Jan. 26, 2009 10:06 a.m. ignorant SuperDork

thanks.. I'll see if I can dig up any info on it at home..
Jan. 26, 2009 10:36 a.m. carzan New Reader

The circuit breaker you describe isn't just a standard circuit breaker. It is equipped with a ground fault circuit interrupt feature that is required by code (whether at the outlet or the entire circuit) for wet areas like your bathroom. It is, as has been said before, likely kaput and replacing it would be the most logical course of action at this point. Just make sure you replace it with one that is equipped with GFCI, as well (preferably an exact match).
Jan. 26, 2009 10:51 a.m. ignorant SuperDork

carzan wrote: Just make sure you replace it with one that is equipped with GFCI, as well (preferably an exact match).

yup will do. House is new so probably not a problem to find. Square D is pretty standard stuff.. Also long as its not federal pacific or whatever.. I think I'm OK Had a few of those old dinosaurs at the plant.
Jan. 26, 2009 11:34 a.m. fastEddie Dork

Yeah, SqD is pretty common, I think either of the Big Box home improvement stores will have what you need. In my last house I replace the original mid-50's era fuse box (60A = 4 x 15A fuses) with all new 200A service into the house then a feed from that into the garage with it's own 100A sub-panel. I used SqD QO stuff for that as well.
Jan. 26, 2009 5:23 p.m. ignorant SuperDork

doh.. Friend came over. Traced th fault to a bad light fixture I had just installed.

Idiot. So apparently, even with the switch off, the arc fault could detect the issue with the light fixture.

Now you know why I am a mechanical engineer and not electrical. Electricity is black magic.

Good learning experience though.

From this I can deduce that the humidifier was actually bad as well.
Jan. 27, 2009 5:38 a.m. foxtrapper SuperDork

QO-GFI combination breakers?! You've got a very nice and expensive panel box! I envy you that one.
Jan. 27, 2009 6:23 a.m. SVreX SuperDork

Glad you got your problem solved.

Just to clarify, was it a GFCI, or an an arc-fault breaker?

Ground faults are for wet locations. Arc faults are extra sensitive to arcs, and trip more easily.

BTW- your master bath and your master bedroom shouldn't be wired together. The bath is required to have GFCI's, and the BR is required to have arc-faults.
Jan. 27, 2009 6:32 a.m. ignorant SuperDork

ARC fault, this is for the bathroom light fixture. The plugs near the sink are ground fault....
Jan. 27, 2009 6:46 a.m. SVreX SuperDork

That'll do fine (lighting circuits have always traditionally been done this way), but it is technically incorrect.

Current code (and in 2005) said ALL electricity in baths has to be GFI, including lighting circuits.

That arc-fault could be extra sensitive to the moisture in the air from both the shower steam and the humidifier. Could become an issue later. Just keep it in mind.

Arc faults are a pain to work with (though a good idea).
Jan. 27, 2009 7:26 a.m. ignorant SuperDork

Forgot to mention that the sink is in a separate room from the shower. So it is not really a wet area.
Jan. 27, 2009 9:47 a.m. Jensenman SuperDork

If an electrical outlet (including a light socket) is within 3 feet of a water source it has to be on a GFCI (code regulations). This includes dishwashers, disposals, washing machines, kitchen counter top receptacles yada yada yada. The GFCI can be either the in- receptacle type or the breaker box type, you don't have to have both but some electricians do it anyway. I think that's so everything in a bathroom etc will be on a GFCI regardless of its distance from water.

All outdoor receptacles must be on a GFCI as well since they are exposed to moisture.
Jan. 27, 2009 11:55 a.m. ignorant SuperDork

you could argue that these light fixtures are more than 3 feet from a water source and are "Not located in a bathroom" as they are outside of the room with the dumper/shower combo. seperated by door.
Jan. 27, 2009 12:14 p.m. Jensenman SuperDork

True, true. But if the electrician is sitting in 'The Chair' in court trying to explain why Mr or Mrs Homeowner got zapped by something he installed I bet he'd be wishing like hell he GFCI'd too much rather than not enough.
Jan. 27, 2009 12:37 p.m. foxtrapper SuperDork

You can have an arc fault GFI breaker. That's what I thought you were describing. Expensive buggers, but darn nice to have.
Jan. 27, 2009 12:42 p.m. carzan New Reader

This might be worth a look. Somebody's been printin' up phony breakers! http://www.inspect-ny.com/electric/SquareDRecalls.htm

You'll need to log in to post.