Is there any way to test a breaker?

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Revhendo

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I had a separate circuit added to my garage to run my welder and my air compressor. (Not at the same time). My air compressor gives it fits and pops it on it's take up cycle. I had the compressor checked and they say it's fine. The compressor is an old old old Craftsman 2.5 hp 120v unit. I don't really want to get a new compressor, but I need air. How can I test my garage power to make sure I'm getting my juice?

OH, and burning down the garage is not an option. :)

edit: it's only a 2hp motor.
 
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A breaker has 3 positions. On off and tripped. tripped is in the middle. easiest way it turn breaker off then turn back on. what is your voltage in the USA? 240 volt? here we are 208
 
A breaker has 3 positions. On off and tripped. tripped is in the middle. easiest way it turn breaker off then turn back on. what is your voltage in the USA? 240 volt? here we are 208
Is that in Imperial or Lucas volts? :poke:

J/K. It's 120/240. I am aware of how a breaker works. I need to know if there is a way to see if it is holding the proper amps.
 
its either the motor is pulling to many amps or the breaker is just weak. if you have a meter with an amp probe you can check it yourself while the compressor is running.there should be a plate on the motor that tells you what the amp and voltage ratings of the motor. i would guess you would need at least a 50 amp breaker . a 2.5 hp motor under full load i would guess it would take 35 amps i am no electrical guru just an old maintenance mechanic
 
I had a separate circuit added to my garage to run my welder and my air compressor. (Not at the same time). My air compressor gives it fits and pops it on it's take up cycle. I had the compressor checked and they say it's fine. The compressor is an old old old Craftsman 2.5 hp 120v unit. I don't really want to get a new compressor, but I need air. How can I test my garage power to make sure I'm getting my juice?

OH, and burning down the garage is not an option. :)

Is the unloader working on the compressor? If not, the motor is trying to start against too much head pressure causing the motor to pull too many starting amps.
 
Is the unloader working on the compressor? If not, the motor is trying to start against too much head pressure causing the motor to pull too many starting amps.
Compresser was checked out. The pressure relief is working. (according to the expert at the compressor shop).
 
It's a 20 amp in the sub panel in the garage that pops. The 240 feed in the same panel is a dual pole 80 amp breaker.
 
If you look at the name plate on the motor it will tell you what the full load amps of the motor is.The tag will probable say fla then a number like 2.5 means it draws 2.5 amps at full load your breaker needs to be double that because it draws more amps when it starts all motors do..Put a amp probe on the hot wire coming out of the breaker and see how many amps it draws.Lets say the breaker is 15 amps and the breaker kicks when it reads 10 amps the breaker is bad
 
If you look at the name plate on the motor it will tell you what the full load amps of the motor is.The tag will probable say fla then a number like 2.5 means it draws 2.5 amps at full load your breaker needs to be double that because it draws more amps when it starts all motors do..Put a amp probe on the hot wire coming out of the breaker and see how many amps it draws.Lets say the breaker is 15 amps and the breaker kicks when it reads 10 amps the breaker is bad
20170116_150723.jpg

How's this?
 
that motor is going to spike more than the 15 amps that its rated for when it initially goes under load. 20 amp breaker is prob the minimum breaker you can run with that set up. with out actually checking it i would say the breaker has a bad heater in it.i would replace it
 
that motor is going to spike more than the 15 amps that its rated for when it initially goes under load. 20 amp breaker is prob the minimum breaker you can run with that set up. with out actually checking it i would say the breaker has a bad heater in it.i would replace it
I agree, it will probably spike higher than the full 20 amps at re-start. A "slow-blow" breaker like this:

IMG_1246.PNG


Probably need to buy two and link their switches together if you buy this specific one. Without doing more research to see if this is specifically made. Look for "high magnetic" in the circuit breaker description. Plus get the one that fits your panel (I.e. Square D, GE, etc.).

If you have your compressor plugged into an extension cord, don't! Plug it directly into the wall with the shortest cord possible.
 
My advice.
Swap the motor to 230. Connections are on the motor.
Change the breaker to 230.
Wire is already there, right?
You are cutting your current draw in half.
Change the receptacle and plug to do it right.
Your motor will thank you for it.
 
My advice.
Swap the motor to 230. Connections are on the motor.
Change the breaker to 230.
Wire is already there, right?
You are cutting your current draw in half.
Change the receptacle and plug to do it right.
Your motor will thank you for it.
Yeah, my advice above was for this. I assumed it was already wired that way. But if it is already wired for 120, the high magnetic breaker may be all that's need to fix it. But the higher voltage way is the way to go if he already has enough wires run to the outlet box to support it.
 
When I had the extra line ran to the garage, I had asked for a 30 amp breaker. It was a buddy trade deal (sort of, still cost me some coin). I had never even noticed that it was a 20 amp breaker. I had two spots where the 120 outlets were run and there is one 240 outlet with a dual pole 80 amp breaker.

I had changed to old and hacked power cord out to a 6ft 12g cable thinking the cord might be the problem. It didn't help.
Without knowing the gauge of wiring installed, I think I'll try another 20amp breaker. Barring that, this is the first time I saw the 240 wiring on the motor, so that might just be step 2.
 
For what its worth, my very old Craftsman table saw has tripped the 110-20 amp breaker from time to time. It's a cable driven blade so no belt to slip.
My compressor ( very old Sanborn Black Max 5 hp ) has always been wired on a 220-30 amp double pole and never ever tripped that breaker.
 
For what its worth, my very old Craftsman table saw has tripped the 110-20 amp breaker from time to time. It's a cable driven blade so no belt to slip.
My compressor ( very old Sanborn Black Max 5 hp ) has always been wired on a 220-30 amp double pole and never ever tripped that breaker.
They always say the older stuff is better. The specs on this compressor aren't matched by anything out there that I can find, so I would like to keep it.

I feel like a dufus for not noticing that it was only a 20 amp breaker, but I wasn't using my compressor for more than inflating tires for the longest time. The downside to rechargeable battery power tools. My mig never had a problem, but I wasn't welding heavy stuff, either. By the time I noticed, my "friend" went all vapor on me.

Such as life.
 
I have a 30a 110 breaker for my camper plug in, if you have 10 guage wire, you may be able to find a 30a 110 breaker for your box! Not every company has them, I know the "homeline" Square D doesn't!!

We had 2 slushy machines hooked up there for Nellas grad party! They have a very high amp draw on the cooling compressor, never popped the breaker!!!
 
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746watts =1hp IIRC,so 2hp is about 1500,and 1500/120=12.5Amps
The motor plate says 15, so that is a 20% safety, or My memory is poorer than I thought.
If it draws double to start, when the unloader is properly adjusted,then you would need 20/25 common breaker.
The slo-blow is a good option
But, another is to just crank down the unloader, and wait an extra bit for the pressure to come up.
Breaker-heaters do get tired after too many trips.
 
Yeah, my advice above was for this. I assumed it was already wired that way. But if it is already wired for 120, the high magnetic breaker may be all that's need to fix it. But the higher voltage way is the way to go if he already has enough wires run to the outlet box to support it.

Let's assume he has 12/2 with ground wire for a 20 amp breaker.
I think he doesn't know. But it should be that IIR.
(Even so if someone went cheep and ran 14/2 swapping to 230 would definitely be the way to go.)
So if he uses that 12/2 wire and puts in a 230 it's a win win.
Or maybe even a win win win.
I'm posting for his benefit.
I know you know.
 
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