[SinCityKid]

I am hoping I can get some help on a breaker that keeps tripping. In my garage I recently added two dedicated 20amp outlets and a 220 outlet for a welder. The breaker box is literally right above the outlets and the run is about two feet. I used 12 gauge wire on the 20 amp outlets and 6 gauge for the welder. When I plug my 7.5 amp compressor into the right outlet and turn it on it immediately trips the breaker. When I plug it in the left side it works great. Other smaller items like my radio, vacuum, battery charger etc all work fine in the right outlet, just not the compressor.

Here's what I'm looking at...

I replaced the breaker thinking maybe it was weak or something but the new breaker is doing the same thing.... left side works great, right side works great for everything but the compressor. I put an amp meter on the right side and set it to "MAX" to capture the highest amp reading but it trips so fast I can't even get a reading. The only thing I haven't done is replaced the outlet because I just don't have a 20 amp outlet at my fingertips right now. I'm just looking for some advice on where to look for the problem.

Thanks in advance.

 

[Jim Port]

How did you wire the receptacles?

 

[joecaption]

Metal box?

 

[SinCityKid]

Not Sure I know what you mean by how did I wire it, but the outlets are two separate circuits. Two hots, two neutrals and one ground. Attached using the screws on the sides of the outlets. Plastic box.

 

[Missouri Bound]

Switch the wires on the breakers and see if the problem moves. :yes:

 

[SinCityKid]

Switch the wires on the breakers and see if the problem moves. :yes:

Good idea! So I switched the wires so the top breaker now controls the left side. When I turn on the compressor the left side is tripping the top breaker and the right side works fine now. I checked my line voltages and I got 120.3 on one and 120.7 on the other. like I mentioned before this is the second breaker, same problem. Not sure where to go from here...

 

[SinCityKid]

It seems to me the problem is either with that top breaker or the voltage on that leg. I temporarily moved the outlet wire down 1 breaker to the existing 20 amp breaker so I could pull from the same leg as the top breaker that has been giving me problems (I hope that makes sense). That worked fine so the only conclusion I can make is that the top breaker is bad. I just have trouble thinking that two breakers would be bad in the exact same way.

 

[eastcoastsparky]

What does the manufacture say what size breaker? Im thinking that because when a motor first starts it can draw up to six times the running load current. You said it draws 7.5 amps, so let me see, 7.5*6=45

 

[paintdrying]

You need to drain the compressor and leave the drain plug open so their is less resistance when the compressor be kickin on. After the compressor starts close the drain or you will kill your compressor. As a matter of policy, in a shop i always put my grounds on the top when installing outlets.

 

[SinCityKid]

What does the manufacture say what size breaker? Im thinking that because when a motor first starts it can draw up to six times the running load current. You said it draws 7.5 amps, so let me see, 7.5*6=45

I was running this compressor on a 15 amp circuit and it did just fine. I had to start using a 50 foot extension cord which is where I ran into problems after long run times, thus necessitating my new outlet. However even with the 15 amp circuit and an extension cord the inrush current was never a problem so I don't think that is my issue.

 

[SinCityKid]

You need to drain the compressor and leave the drain plug open so their is less resistance when the compressor be kickin on. After the compressor starts close the drain or you will kill your compressor. As a matter of policy, in a shop i always put my grounds on the top when installing outlets.

Good thought. thanks! Just curious what the purpose of putting the grounds on top is...?

 

[paintdrying]

If a metal rod would happen to fall, knock the plug loose then it would connect hot and neutral causing a short. As opposed to hitting the ground terminal.

 

[jbfan]

If a metal rod would happen to fall, knock the plug loose then it would connect hot and neutral causing a short. As opposed to hitting the ground terminal.

Crazy reason.
You have the same chance for whatever falls to hit the ground and hot instead of the ground and neutral!

 

[beenthere]

I'd open the recep box up and make sure that no bare wires aren't too close and able to touch when under a higher load.

 

[oh'mike]

I'm wondering why you haven't pulled everything out of the box yet---I'll bet you will find a wire has come off one of the outlets----or something that will be obvious if you have the outlets out of the box

 

[al_smelter]

With two feet of wire and everything right at your fingertips, you should find the issue fairly quickly. I have personally never had a lot of luck with the little 'mini combo' breakers. So I wouldn't discount another bad breaker. And just double check all your connections. You are already on the right track without a lot of help from us.

As far as ground up or ground down- that is akin to religion or politics in this trade. There is nothing in the NEC concerning ground up or down...your preference. Hospitals install ground up with the theory someone has already stated. If bits or pieces fall across the plug it MIGHT hit the ground pin first and disengage the plug from the wall. I say it's a stretch, but what can it hurt?

Let us know what the final issue turns out to be please.

Mark

 

[k_buz]

I've had a fish tape land across the hot/neutral prongs of a partially plugged in cord, but I usually install ground down. That said, I would match what is existing.

 

[md2lgyk]

Crazy reason.
You have the same chance for whatever falls to hit the ground and hot instead of the ground and neutral!

Aah, the perpetual "which way is an outlet right side up" discussion. I know it makes no difference code-wise, but I always install them with the ground at the bottom. The other way just looks "wrong."

 

[64pvolvo1800]

Good idea! So I switched the wires so the top breaker now controls the left side. When I turn on the compressor the left side is tripping the top breaker and the right side works fine now. I checked my line voltages and I got 120.3 on one and 120.7 on the other. like I mentioned before this is the second breaker, same problem. Not sure where to go from here...

Problem follows the breaker so the breaker IS the problem. Remove it and check the connection to the buss and for kicks and giggles you can check the resistance across the pole and the outlet screw. You may find high ohms in which case it will open when it becomes an active part of the circuit instead of just a switch.

Inrush current obviously isnt the problem if the other breaker holds up fine.

 

[Troy32]

Funniest thread title I have seen in a long time.:thumbup: