Breaker Problem
#1
12-25-04, 11:51 AM
Breaker Problem
After reviewing the existing posts, I think I already know the answer to this question, but thought I'd see if anyone had any insights on this problem.
I have an existing outlet in my garage, which looks like it has small gauge wire (not sure exactly the size, but it looks like the same size wire that I have in my indoor receptacles, so maybe 10 gauge. The receptacle has to 3-prong outlets).
Anyway, the circuit is connected to a 15amp breaker in the box. I have been running multiple power tools from the outlet, but when I hooked up a new air compressor, the motor ran very slowly and eventually tripped the breaker. The compressor literature recommends a 15amp breaker, but that obviously does not work in my situation. Can I upgrade to a higher capacity breaker (20amp?) without rewiring? What other options do I have to resolve the problem?
Would appreciate any advise.
I have an existing outlet in my garage, which looks like it has small gauge wire (not sure exactly the size, but it looks like the same size wire that I have in my indoor receptacles, so maybe 10 gauge. The receptacle has to 3-prong outlets).
Anyway, the circuit is connected to a 15amp breaker in the box. I have been running multiple power tools from the outlet, but when I hooked up a new air compressor, the motor ran very slowly and eventually tripped the breaker. The compressor literature recommends a 15amp breaker, but that obviously does not work in my situation. Can I upgrade to a higher capacity breaker (20amp?) without rewiring? What other options do I have to resolve the problem?
Would appreciate any advise.
#2
12-25-04, 01:35 PM
Member
Probably not. But figure out what size that wire is for sure.
Depending on what year your house was built, there is likely a lot of other stuff all around your house on the same circuit with that garage receptacle.
Depending on what year your house was built, there is likely a lot of other stuff all around your house on the same circuit with that garage receptacle.
#3
12-25-04, 02:30 PM
Thanks, John.
The breaker label on the box is: GFCI and WP, which I guess means Wall Panel? Anyway, there are only three other electrical things in the garage, an air handler, which has its own breaker and a switch/breaker in the garage, and an overhead florescent light. I don't remember if I had the overhead light on when I tried to run the compressor. I also have a garage door opener, which I was not running.
I guess the only way to check the gauge of the wire is to use the wire cutter gauge?
Again, I appreciate any and all help.
Sean
The breaker label on the box is: GFCI and WP, which I guess means Wall Panel? Anyway, there are only three other electrical things in the garage, an air handler, which has its own breaker and a switch/breaker in the garage, and an overhead florescent light. I don't remember if I had the overhead light on when I tried to run the compressor. I also have a garage door opener, which I was not running.
I guess the only way to check the gauge of the wire is to use the wire cutter gauge?
Again, I appreciate any and all help.
Sean
#6
12-25-04, 02:47 PM
After closer inspection, the garage receptacle does seem to be in a loop of some sort. There are two black wires and two white wires connected to the receptacle, which suggests additional electrical demands being placed on the circuit, I guess.
Sean
Sean
#7
12-25-04, 09:49 PM
Member
The additional loads could be anywhere, including 100 feet away on the far side of the house. My previous post contained a hint for you to tell us when your house was built, but now I'll ask it straight out: in what year was your house built?
#8
12-26-04, 02:04 AM
If your air compressor is powered by an induction motor the starting amps can be 3 times greater then the running current.
An induction motor that uses 15 amps running, will need about 45 amps to start for about 5 seconds.
The other motors used on compressors have carbon brushes, they don't need as hi starting amps.
the draw back is they don't hold up as well as the induction motors.
The problem your having is characteristic to a induction motor.
Most starting problems with compressors start with, to long of a cord/wire from the breaker panel.
The longer the wire the more of a voltage drop you have.
To compensate for the length you need to increase the size/gauge of the cord/wire.
That voltage drop can prevent a motor from getting the full starting amps needed.
So the induction motor may stall at 30 amps tripping the breaker with out starting.
The stalling can burnout the motor.
Most breakers have some delay allowing motors to start.
You must NOT put a 20 amp breaker on existing wire rated for 15 amps.
Breakers in your panel are sized to the wire gauge and the length of the run/wire.
If you pull 20 amps through wire rated at 15 amps the wire will get hot and may start a fire without tripping the breaker.
There is a reason why a 15 amp breaker in installed.
As a test. try plugging it into a plug closer to your breaker panel.
What type of motor do you have ?
What is the distance from (length of wire) your breaker panel to the plug you are trying ?
Are you tripping a GFI or a circuit breaker ?
An induction motor that uses 15 amps running, will need about 45 amps to start for about 5 seconds.
The other motors used on compressors have carbon brushes, they don't need as hi starting amps.
the draw back is they don't hold up as well as the induction motors.
The problem your having is characteristic to a induction motor.
Most starting problems with compressors start with, to long of a cord/wire from the breaker panel.
The longer the wire the more of a voltage drop you have.
To compensate for the length you need to increase the size/gauge of the cord/wire.
That voltage drop can prevent a motor from getting the full starting amps needed.
So the induction motor may stall at 30 amps tripping the breaker with out starting.
The stalling can burnout the motor.
Most breakers have some delay allowing motors to start.
You must NOT put a 20 amp breaker on existing wire rated for 15 amps.
Breakers in your panel are sized to the wire gauge and the length of the run/wire.
If you pull 20 amps through wire rated at 15 amps the wire will get hot and may start a fire without tripping the breaker.
There is a reason why a 15 amp breaker in installed.
As a test. try plugging it into a plug closer to your breaker panel.
What type of motor do you have ?
What is the distance from (length of wire) your breaker panel to the plug you are trying ?
Are you tripping a GFI or a circuit breaker ?
#9
12-26-04, 06:16 AM
In response to John and Gwiz:
John, the house was final inspected in 2001, so it is not that old. I think Gwiz is on the right track. The outlet in question is about 60 feet in a straight line from the breaker. (Breaker panel is on one end of the house, the outlet at the other end.) The compressor does, in fact, work when I connect it to an outlet directly under the breaker panel.
So, assuming that the issue is a combination of undersized wiring/breaker and the distance from the breaker panel, what should I do to resolve this issue?
Sean
John, the house was final inspected in 2001, so it is not that old. I think Gwiz is on the right track. The outlet in question is about 60 feet in a straight line from the breaker. (Breaker panel is on one end of the house, the outlet at the other end.) The compressor does, in fact, work when I connect it to an outlet directly under the breaker panel.
So, assuming that the issue is a combination of undersized wiring/breaker and the distance from the breaker panel, what should I do to resolve this issue?
Sean
#10
12-26-04, 09:11 AM
Member
WP=water pump? well pump? winter porch? water closet (sloppy handwriting)? washer/dryer?
Might be an excellent idea to figure out exactly what WP stands for. It's a lot easier to figure it out now than when you the circuit is dead at some time in the future.
Might be an excellent idea to figure out exactly what WP stands for. It's a lot easier to figure it out now than when you the circuit is dead at some time in the future.
#11
12-26-04, 11:15 AM
Yes, John.
It just occured to me this morning as I was looking around the outside of the garage that there is a small water fountain located just outside the garage that uses a water pump to recirculate water. The switch to turn on the water pump is not located in the garage but in another (bath)room. Would the water pump place load on the circuit even if it was not running?
Again, I suspect that Gwiz is on the right track in his analysis that the distance from the breaker, combined with the gauge of wire to the outlet, is the primary culpret.
My only question at this point is what to do about the problem, given that the breaker panel is 60 or so feet away from the garage outlet. It would be a nightmare (not to speak of expense!) to run new wire to that outlet, so I would prefer another solution, if one is available.
Sean
It just occured to me this morning as I was looking around the outside of the garage that there is a small water fountain located just outside the garage that uses a water pump to recirculate water. The switch to turn on the water pump is not located in the garage but in another (bath)room. Would the water pump place load on the circuit even if it was not running?
Again, I suspect that Gwiz is on the right track in his analysis that the distance from the breaker, combined with the gauge of wire to the outlet, is the primary culpret.
My only question at this point is what to do about the problem, given that the breaker panel is 60 or so feet away from the garage outlet. It would be a nightmare (not to speak of expense!) to run new wire to that outlet, so I would prefer another solution, if one is available.
Sean
