Slightly OT, but I have a “new” wood shaper, a 1952 Delta with the original Repulsion/Induction motor and a mag starter. I notice that when it runs, I sometimes get a very slight electrical tingle from metal surfaces. The motor leads are in good shape and I redid all the starter wiring. The machine is wired for 220 and has a ground that is attached to new bare metal at the cabinet and the motor. I confirmed continuity between the ground blade of the plug and the table, and also that the outlet is grounded. I can’t find continuity from motor leads to ground or starter terminals to ground. I even tried measuring current, AC volts, and DC volts from table to ground, though my cheapo digital multimeter may not be capable enough. That was enough excuse to order a decent one, but in the mean time, can anyone suggest what might be going on?
Pete
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If it works at all even the cheapest DVM should work for this purpose.
The only thing better would be some specialized stuff like Meggers and microamp reading clamp on amp meter.
With the meter on the lowest ohm scale check that the part of the metal does have continuity to the ground pin.
And this is like many pieces of equipment the cabinets are a bunch of piece of metal bolted together. It is possible that there is enough rust around the screws and nuts. It would not hurt to one by one loosen then up a turn and then tighten then backup.
And on the hight resistance scale, and with the unit unplugged measured between the hot and the metal and between the neutral and the metal.
And go back and check the connections on the wiring ground wire include making sure that it is tight at each terminal and the wire nuts are tight.
"I sometimes get a very slight electrical tingle from metal surfaces."
I have also noticed sometimes I have metal splinter in my finger or a rough edge on the metal that gives me a "tingle like" feeling but find that it is a nerve response and not from the power.
William the Geezer, the sequel to Billy the Kid - Shoe
There's definitely continuity from all metal surfaces including the table to the ground of the plug. There is no neutral wire since it's a 240V machine. The tingle is noticeable at different locations on the machine, but not consistently. I sure hope there's no ground issue with the house, it's only 9 years old.Pete
Edited 1/28/2009 5:35 pm ET by PeteBradley
> I sure hope there's no ground issue with the house, it's only 9 years old.
The age of the house tells you nothing. Lots of homes get wired wrong from the start.
The modern conservative is engaged in one of man's oldest exercises in moral philosophy; that is, the search for a superior moral justification for selfishness. -John Kenneth Galbraith
From either leg of the outlet (an L6-20R), I get 120 when compared to ground. FWIW, there's also continuity between the ground slot and the plumbing.Pete
Any chance it's static related since it only happens when the machine is running? I wonder if you ran a grounding strap from a bolt on the worktop to a ground what would happen?PaulB
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Great point.
When I ran one of my shapers with dust collection, I got shocked from the air moving through the hose.
It's possible that the tingle is due to voltage from something else and the shaper is just providing the ground.
It's also possible that you have a bad ground connection in the house wiring.
Ditch the old motor, it likely has bad/deteriorated insulation. Could just be a leaky start capacitor also with the leaky electrolyte providing a path to case.
Have never felt a 'tingle' from static, always a little single jolt occasionally.
R/I motors don't have caps. They use a wound rotor with a shorting device that turns it into an induction-type rotor at running speed. I just rebuilt the motor and the wires were in near-mint condition. Ditching it is undesirable for a number of reasons besides the considerable cost.The zing is gone, which lends some credence to the static theory. I do measure a voltage from table to ground, but my suspicion is it's a ghost voltage. I have a much better multimeter on the way, I'll do more checks when I get it.
Edited 1/29/2009 5:00 pm ET by PeteBradley
"I do measure a voltage from table to ground, but my suspicion is it's a ghost voltage."Now much voltage and under what conditions?And where you using a digital voltmeter?A ghost or phantom voltage requires an open circuit..
William the Geezer, the sequel to Billy the Kid - Shoe
I disconnected the ground at the machine and then read voltage between the machine and the ground. With power applied but starter not engaged it reads 14 volts, with the starter engaged and motor running it reads about 2. What I was trying to measure was leakage to ground, but I wondered if the readings might just be a capacitative ghost voltage. It occurs to me that measuring amps would probably be better.Pete
Edited 1/29/2009 5:40 pm ET by PeteBradley
Yes, with the ground open all you are measure is capacitivy coupling or phantom voltage..
William the Geezer, the sequel to Billy the Kid - Shoe