Old Electric Motor

[Howard H.]

I was working on refurbishing an old Delta/Rockwell drill press I picked up for nothing at an auction with a bad motor. I found an old Dayton 1 1/2 hp electric motor out in the barn. It is a dual voltage - 230 or 120 motor.

It may be 10 years old or 25, and I don't know the history on it, but when I hooked it up, it spun free and easy, so I mounted it on my drill press.

The rotation was wrong, so I reversed the leads per the label on the motor of the 120 volt wiring diagram, and it corrected the rotation as indicated...

I used it several times - and was quite pleased with myself, until I was drilling on something long and metal - and the end of my workpiece hit the frame of the barn and instantly blew a big arc - and blew the circuit breaker.

In checking more carefully, the entire drill press is energized at full voltage while it is turned on. There is no voltage while the power switch is off.

I guess by wearing rubber sole shoes, I wasn't shocked.

I thought at first, I must have mis-wired it, but in double checking everything, it is correct per the label diagram and per the lead numbering. The wires to the capacitors look fine - and clean - and capacitors look fine as well. I don't have any shorts up until the point the power wires go into the motor.

My questions are:

Is it possible for the motor to be bad in a way that it can energize the drill press frame - while still working fine in terms of spinning under power?

How could I test the leads to determine an internal short of the motor?

Does the fact that it is energized while on mean that the barn grounding is faulty? I wired in a heavy three-wire power cord and 3 prong plug-in to the drill press and the ground wire is bolted firmly to the ground point. But Dad had the barn built probably 50 years ago when I was a kid, so even though all the barn wiring is professionally installed in metal conduit, etc, it is pretty old.


Thanks for any advice,
Howard

 

[greenmech]

I was working on refurbishing an old Delta/Rockwell drill press I picked up for nothing at an auction with a bad motor. I found an old Dayton 1 1/2 hp electric motor out in the barn. It is a dual voltage - 230 or 120 motor.

It may be 10 years old or 25, and I don't know the history on it, but when I hooked it up, it spun free and easy, so I mounted it on my drill press.

The rotation was wrong, so I reversed the leads per the label on the motor of the 120 volt wiring diagram, and it corrected the rotation as indicated...

I used it several times - and was quite pleased with myself, until I was drilling on something long and metal - and the end of my workpiece hit the frame of the barn and instantly blew a big arc - and blew the circuit breaker.

In checking more carefully, the entire drill press is energized at full voltage while it is turned on. There is no voltage while the power switch is off.

I guess by wearing rubber sole shoes, I wasn't shocked.

I thought at first, I must have mis-wired it, but in double checking everything, it is correct per the label diagram and per the lead numbering. The wires to the capacitors look fine - and clean - and capacitors look fine as well. I don't have any shorts up until the point the power wires go into the motor.

My questions are:

Is it possible for the motor to be bad in a way that it can energize the drill press frame - while still working fine in terms of spinning under power?

How could I test the leads to determine an internal short of the motor?

Does the fact that it is energized while on mean that the barn grounding is faulty? I wired in a heavy three-wire power cord and 3 prong plug-in to the drill press and the ground wire is bolted firmly to the ground point. But Dad had the barn built probably 50 years ago when I was a kid, so even though all the barn wiring is professionally installed in metal conduit, etc, it is pretty old.


Thanks for any advice,
Howard

Test continuity from the leads on the plug to ground and should show open. If otherwise you have a short in the motor. Ron MN

 

[used red MN]

Test continuity from the leads on the plug to ground and should show open. If otherwise you have a short in the motor. Ron MN

I agree with Ron, on the other hand by your description of the happenings namely the arcing to the metal building frame would suggest to me if your wiring is proper the breaker should have blown when you turned it on. Sounds to me like investigating if there is a proper grounding to the third round prong receptacle hole in the outlet is also in order.

 

[Bob Bancroft]

I was working on refurbishing an old Delta/Rockwell drill press I picked up for nothing at an auction with a bad motor. I found an old Dayton 1 1/2 hp electric motor out in the barn. It is a dual voltage - 230 or 120 motor.

It may be 10 years old or 25, and I don't know the history on it, but when I hooked it up, it spun free and easy, so I mounted it on my drill press.

The rotation was wrong, so I reversed the leads per the label on the motor of the 120 volt wiring diagram, and it corrected the rotation as indicated...

I used it several times - and was quite pleased with myself, until I was drilling on something long and metal - and the end of my workpiece hit the frame of the barn and instantly blew a big arc - and blew the circuit breaker.

In checking more carefully, the entire drill press is energized at full voltage while it is turned on. There is no voltage while the power switch is off.

I guess by wearing rubber sole shoes, I wasn't shocked.

I thought at first, I must have mis-wired it, but in double checking everything, it is correct per the label diagram and per the lead numbering. The wires to the capacitors look fine - and clean - and capacitors look fine as well. I don't have any shorts up until the point the power wires go into the motor.

My questions are:

Is it possible for the motor to be bad in a way that it can energize the drill press frame - while still working fine in terms of spinning under power?

How could I test the leads to determine an internal short of the motor?

Does the fact that it is energized while on mean that the barn grounding is faulty? I wired in a heavy three-wire power cord and 3 prong plug-in to the drill press and the ground wire is bolted firmly to the ground point. But Dad had the barn built probably 50 years ago when I was a kid, so even though all the barn wiring is professionally installed in metal conduit, etc, it is pretty old.


Thanks for any advice,
Howard

Novice asking questions here-
So it's a steel building?
Is there a ground cable emanating from the panel and going to a ground rod, or some other good ground?

 

[Howard H.]

Thanks for the advice!

It turned out to be a combination of bad power receptacle and there was an intermittent internal short between the power wire and ground in the power cord to the motor...

The motor was fine all along...

 

[ed12345]

I was working on refurbishing an old Delta/Rockwell drill press I picked up for nothing at an auction with a bad motor. I found an old Dayton 1 1/2 hp electric motor out in the barn. It is a dual voltage - 230 or 120 motor.

It may be 10 years old or 25, and I don't know the history on it, but when I hooked it up, it spun free and easy, so I mounted it on my drill press.

The rotation was wrong, so I reversed the leads per the label on the motor of the 120 volt wiring diagram, and it corrected the rotation as indicated...

I used it several times - and was quite pleased with myself, until I was drilling on something long and metal - and the end of my workpiece hit the frame of the barn and instantly blew a big arc - and blew the circuit breaker.

In checking more carefully, the entire drill press is energized at full voltage while it is turned on. There is no voltage while the power switch is off.

I guess by wearing rubber sole shoes, I wasn't shocked.

I thought at first, I must have mis-wired it, but in double checking everything, it is correct per the label diagram and per the lead numbering. The wires to the capacitors look fine - and clean - and capacitors look fine as well. I don't have any shorts up until the point the power wires go into the motor.

My questions are:

Is it possible for the motor to be bad in a way that it can energize the drill press frame - while still working fine in terms of spinning under power?

How could I test the leads to determine an internal short of the motor?

Does the fact that it is energized while on mean that the barn grounding is faulty? I wired in a heavy three-wire power cord and 3 prong plug-in to the drill press and the ground wire is bolted firmly to the ground point. But Dad had the barn built probably 50 years ago when I was a kid, so even though all the barn wiring is professionally installed in metal conduit, etc, it is pretty old.


Thanks for any advice,
Howard

sounds like a wiring issue

Years and years ago if you got a shock from a refrigerator you would just turn the plug over and stick it back in - shock eliminated

Start with the easiest - no cost possibilities first

use a volt meter and check:

1.) your wall plug just to make sure its wired correctly and test the hot, neutral and ground -- then test them to the part of the shed that sparked. Most important is that the plug ground to shed wall should read no voltage. Hot to ground & shed wall should be close to 120V, Neutral to ground & shed wall should have no voltage (could have a small voltage if your total barn load is unbalanced)

2.) On the drill Press - trace the hot and neutral wires from the plug all they way to the motor and how it connects to the motor's wire configuration (the wires for voltage and rotation). Make sure the hot wire is not shorting or connected to any ground points or neutral wires/terminals. Check that the ground is connected properly.

Assume the drill press is hot for safety - plug in and turn on --- if the fuse pops you have a bad motor that needs to be replaced or rebuilt

 

[Jim.ME]

He solved it on Tuesday, read post #5.