Electrical hookup / motor questions (P&W 3c mill)

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SteveM
Posts: 7763
Joined: Mon Jun 27, 2005 6:18 pm
Location: Wisconsin

Electrical hookup / motor questions (P&W 3c mill)

Post by SteveM »

I finally got around to setting up the P&W on the new bench that I got.

This bench came with another 3C that I sold (to Jim Rozen). I kept the power switch (one of the reasons I bought the mill). It was wired to the motor, so I color-coded all the wires so that I could put it all back together.

The motor dates back to at least the late 1960's, as I found a wiring diagram inside the mill that was so dated. It was probably an old motor when it was put in.

Well, I got it all back together, and all I got from the motor was hum. When I turned the motor, it turned, but at a slow speed with no torque. Reversing the switch makes the motor reverse, but the same symptoms.

The switch is complex, with two rows of seven contacts each side. The switch is designed to run a three-phase , two-speed motor in forward and reverse. My setup has only a single-speed, single-phase motor. The switch has limiters so that it only goes to the first position in each direction. The manual has no information about hooking up the switch.

There is a two-conductor wire that goes to the motor, into a box on the side, which looks like the power to the motor. The other wire is a four-conductor that goes to four wires that come out of the end of the motor.

I can't read the plate on the end of the motor - it's too scratched up. It's a capacitor-start motor, as there is a big can on the side.

I have other motors, but none has connections like this one.

So, where do I go from here? If this motor is repairable (is the cap bad?), I could do that, but is it worth saving?

I could use another motor, but I'd have to figure out how to hook it up.

Steve
hammermill
Posts: 2938
Joined: Sun Jun 27, 2010 10:43 pm
Location: pendleton or

Re: Electrical hookup / motor questions (P&W 3c mill)

Post by hammermill »

here are a few diadrams in a fact sheet that are pretty standard for single and 3 phase aplications



http://www.conveyorsolutions.com/images ... ing105.pdf


hope this helps
SteveM
Posts: 7763
Joined: Mon Jun 27, 2005 6:18 pm
Location: Wisconsin

Re: Electrical hookup / motor questions (P&W 3c mill)

Post by SteveM »

That's an good reference. I saved that for some drum switches I have.

The motor I'm likely to use has only connections of L1 and L2, not T1 through T8. I found the wiring diagram inside the cover, and there are red and green wires that connect to L1 and L2, and if you reverse those, the motor reverses.

If I connect the red and green back to the switch through the four-conductor wire and back to the motor where they would connect, then connect L1 and L2 to the power, that may do it, but I just need to figure out which wire goes where.

Steve
hammermill
Posts: 2938
Joined: Sun Jun 27, 2010 10:43 pm
Location: pendleton or

Re: Electrical hookup / motor questions (P&W 3c mill)

Post by hammermill »

look over the contact diagram for the drum switch and remenber 5 an8 are reversed in relation to the l1 l2 conection and you will be all right maybe lay out with colored pens would help
jim rozen
Posts: 410
Joined: Sun Nov 18, 2007 12:46 am
Location: peekskill, ny

Re: Electrical hookup / motor questions (P&W 3c mill)

Post by jim rozen »

How odd, Steve. I just got done wiring up the machine you sold me, with a 3/4 hp
three phase motor, and a Teco VFD. At the moment it's driven direct from the motor
to the spindle pulley, no countershaft. I'm a bit short on vises (still to be purchased)
but the machine cut its first metal in the basement shop last night!

It's a really sweet machine, I'll put some photos of the drive setup here soon.
Next up is an arm for the end of the overarm support.

Best - Jim
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