Tool Problems - coincidence or did I botch my garage electrical wiring? (1 Viewer)

[Ruggedly]

The receptacle branch circuits are on 20A breakers, so a #12 wire is the correct size (assume the length is not too long). He only has 15A rated receptacle devices in the boxes, but that is acceptable per NEC (since he has more than one device in the circuit). If it was a single dedicated receptacle on a 20A circuit, then it would need to be a 20A rated device.

I would get a RELIABLE voltage meter, put it on the circuit and run the tool, watch what the voltage does. A clamp-style ammeter would also be helpful, if you can get one.

Thanks @KLF. I went with this guy due to budget restrictions right now. Think it will do the job? It's well-loved on Amazon, but not exactly a Fluke.

Amazon.com: Etekcity Auto Ranging Clamp Meter, Digital Multimeter with Amp,Volt,Ohm,Diode and Resistance Test: Automotive

Buy Etekcity Auto Ranging Clamp Meter, Digital Multimeter with Amp, Volt, Ohm, Diode and Resistance Test: Clamp Meters - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

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[KLF]

Unlikely a breaker would trip because of amp loss as you seem to think, from what I know.)

Just a minor correction: you don't lose amps in circuits. You lose voltage, usually when the wire is too small for the amperage.

But I concur that this seems like an excessive voltage drop issue. Many years ago before I knew better, I saw a friend burn up his skilsaw by running it on an extension cord that was too long and too small.

 

[Ruggedly]

Just a minor correction: you don't lose amps in circuits. You lose voltage, usually when the wire is too small for the amperage.

But I concur that this seems like an excessive voltage drop issue. Many years ago before I knew better, I saw a friend burn up his skilsaw by running it on an extension cord that was too long and too small.

Thanks. That's helpful. I just find it strange that it's occurring on BOTH circuits. Not to say it's not possible for me to have a bad connection on both, but man, not exactly an ego-boost on my DIY skills.

And the fact that I saw a flicker in the lights (separate 15 amp circuit) when I turned the sander on? What's that about?

 

[KLF]

Thanks @KLF. I went with this guy due to budget restrictions right now. Think it will do the job? It's well-loved on Amazon, but not exactly a Fluke.

Amazon.com: Etekcity Auto Ranging Clamp Meter, Digital Multimeter with Amp,Volt,Ohm,Diode and Resistance Test: Automotive

Buy Etekcity Auto Ranging Clamp Meter, Digital Multimeter with Amp, Volt, Ohm, Diode and Resistance Test: Clamp Meters - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

smile.amazon.com

It might not be the most accurate, but it should at least be close enough to tell you if there is a problem, and where. I have a similar one that is a Craftsman, it's helped me out many times. Just be aware that you will need to pull the receptacle out of the box so you can clamp the meter around the hot conductor only. Or you can get one of these:

Extech 480172 AC Line Splitter - Measuring Gauges - Amazon.com

Extech 480172 AC Line Splitter - Measuring Gauges - Amazon.com

www.amazon.com

 

[rkymtnflyfisher]

I thought you were on a 15 amp breaker, I dig now.

We still need to know what your actual voltage reading is at the receptacles.

Did you say these are on GFCI breakers?

 

[Ruggedly]

It might not be the most accurate, but it should at least be close enough to tell you if there is a problem, and where. I have a similar one that is a Craftsman, it's helped me out many times. Just be aware that you will need to pull the receptacle out of the box so you can clamp the meter around the hot conductor only. Or you can get one of these:

Extech 480172 AC Line Splitter - Measuring Gauges - Amazon.com

Extech 480172 AC Line Splitter - Measuring Gauges - Amazon.com

www.amazon.com

Thanks. I'll just plan to pull it out and clamp around the hot.

 

[rkymtnflyfisher]

And the fact that I saw a flicker in the lights (separate 15 amp circuit) when I turned the sander on? What's that about?

100% normal, it just means there was a large amperage draw on your service. Even though it was on a separate circuit.

 

[Ruggedly]

I thought you were on a 15 amp breaker, I dig now.

We still need to know what your actual voltage reading is at the receptacles.

Did you say these are on GFCI breakers?

Nope, not on a GFCI breaker yet. I plan to add either GFCI breakers or receptacles to the equation soon though.

 

[rkymtnflyfisher]

Thanks. I'll just plan to pull it out and clamp around the hot.

Or just clamp it on the wire in the panel.

 

[rkymtnflyfisher]

Are you 100% certain you dont have something wired backwards?


Black goes on the gold tooth.

 

[Ruggedly]

Are you 100% certain you dont have something wired backwards?


Black goes on the gold tooth.

Pretty certain. I tested the last plug in each circuit with a receptacle tester and both returned "correct" values. One of the few functions of the receptacle tester is that it will flag reversed wires. That being said, once I've done some voltage tests, I'm sure I'll end up confirming the wiring as well. What would the symptoms of swapped wires be?

 

[rkymtnflyfisher]

What would the symptoms of swapped wires be?

Funny things happen.

Capacitors/single phase motors do strange things. Like drawing an unusually high current.

Also verify that you do not have an open neutral. Check continuity between the ground and neutral at a receptacle near the end of the circuit. I doubt you do, but rule it out.

 

[Ruggedly]

Funny things happen.

Capacitors/single phase motors do strange things. Like drawing an unusually high current.

Also verify that you do not have an open neutral. Check continuity between the ground and neutral at a receptacle near the end of the circuit. I doubt you do, but rule it out.

Thank you. That's an interesting possibility then. To confirm, when checking continuity between ground and neutral, an open neutral would cause the neutral to read as hot, correct? Sorry, still learning this stuff.

BTW - So far I'm on page 4 of your build thread. Holy crap it's long! Good stuff so far though! Thanks again for your help on this.

 

[rkymtnflyfisher]

Thank you. That's an interesting possibility then. To confirm, when checking continuity between ground and neutral, an open neutral would cause the neutral to read as hot, correct? Sorry, still learning this stuff.

BTW - So far I'm on page 4 of your build thread. Holy crap it's long! Good stuff so far though! Thanks again for your help on this.

Yes and no.

you want to check for resistance between the two, ideally it will be a low number like 1 or 2 ohms.

Should be no voltage on your neutral. If there is voltage on a neutral you have an open neutral at the panel, most likely.

There’s only a few things that will cause you to get voltage on the neutral even if it is open, keep it simple and unplug everything first.

 

[KLF]

The neutral should be tied to ground, but only in one place: at the service entrance disconnect equipment. Typically this is the main panel. From that point forward, they are kept separate. So you should make sure that in the sub-panel that the neutral is NOT bonded to the panel box, only the ground should be.

You should measure no voltage between the neutral and ground, as electrically they are equal, although a very small amount is not unheard of, due to the voltage drop between the measuring point and where they are tied together, though the various lugs, etc. You should measure close to 120V between the hot and neutral, at every point. And you should measure 240V between the 2 hots inside the subpanel.

 

[doug720]

Another thought - You said that aluminum wire was used between the main panel and new garage panel. Aluminum wire requires a lube at the lugs to insure good contact, stop arcing and prevent corrosion. Was this used?

If not, you could be getting voltage drop?

 

[Ruggedly]

The neutral should be tied to ground, but only in one place: at the service entrance disconnect equipment. Typically this is the main panel. From that point forward, they are kept separate. So you should make sure that in the sub-panel that the neutral is NOT bonded to the panel box, only the ground should be.

You should measure no voltage between the neutral and ground, as electrically they are equal, although a very small amount is not unheard of, due to the voltage drop between the measuring point and where they are tied together, though the various lugs, etc. You should measure close to 120V between the hot and neutral, at every point. And you should measure 240V between the 2 hots inside the subpanel.

Thank you! I will test all of these.

 

[Ruggedly]

Another thought - You said that aluminum wire was used between the main panel and new garage panel. Aluminum wire requires a lube at the lugs to insure good contact, stop arcing and prevent corrosion. Was this used?

If not, you could be getting voltage drop?

I'm assuming this would need to occur at both the main panel and the sub? Would the lube be visibly evident? Are we talking dielectric grease or something else?

 

[e9999]

Rugged, too late now probably, but it might have been a good idea to spring for a clampmeter that also does DC current. Plenty of use for those on the truck. Some decent ones for $50 and up I think.

 

[KLF]

I'm assuming this would need to occur at both the main panel and the sub? Would the lube be visibly evident? Are we talking dielectric grease or something else?

The lube is specifically made for preventing oxidation on aluminum wire at the terminal lugs. "NOALOX" is one brand. It kinda looks like a dark grease, and yes you should be able to see it at the terminal lugs at both ends of the wire.