10ER Motor Cleaning and Wiring

[Chriss]

In a separate thread I asked some questions including about cleaning the motor. I took your advice and blew it out this morning. I got a fair amount of saw dust out, and it looks pretty clean in there now, at least on the one end with vents. The shaft spins well and is smooth, so I suspect it is fine. Is there anything else I should do to it before plugging it in and powering it up?

My other question related to the motor is about the wiring. Looking at the switch and plug, I feel like I should rewire this thing. I'm assuming the switch, cord, and plug are original, but I don't really know. I read somewhere about someone putting in a new grounded cord and 3 prong plug. Seems like a good idea. Thoughts?

Plug and Switch

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Plug end view and Switch

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[JPG]

YES it is a good idea!!!

I recommend getting a heavy duty extension cord for the plug, wire to the switch AND from the switch to the motor. The receptacle end of the cord is surplus.

Are you comfortable with doing that?

[Chriss]

Yes, I am comfortable doing that. I rewired my entire previous house, removing all the knob & Tube and replacing it all with modern wiring (permitted of course). So this is a piece of cake.

Where do I wire the ground? I haven't pulled the tape off the switch to get a better view of the back side, but I assume there is nowhere to attach a ground. How about in the motor?

[everettdavis]

Find a place to ground the green wire to one of the motor screws where the wire makes the best contact with the motor housing. If the motor shorts internally to the case, that will trip the breaker. I try to use CFCI (ground fault circuits) where possible.

Sounds like you have a handle on things pretty well already.

Everett

[Chriss]

Ok, I'll pick up an extension cord and use it to rewire. Just bypass the switch with the ground wire?

It'll be on a GFCI protected circuit in the garage. So no problem there.

[jsburger]

Yes, replace the wiring with a three wire cord and plug. The three wire cord goes to the switch and I run the ground wire to the motor mount. You can just run a 2 wire cord from the switch to the motor. I use #12 stranded wire for all my rewires.

BTW, your switch does not appear to be original but that is not a bad thing.

[Chriss]

Ok, that makes sense. Looks like a good easy spot to run the ground to.

I suppose a 65 year old switch might not be so desireable, so if this isn't original that's fine.

Was there originally some sort of strain releif on the power cord? Mine just runs right up to the back or the switch with no strain relief. That doesn't seem like the best plan. It seems like a wire clamp on the motor mount would be good.

[everettdavis]

Yes. Early switches used Double Pole connections and in later years in the Mark V line they finally moved to switching just the hot (black) leg. They now bond the whites near the motor with the ground and run a segment up to the switch with the live wire.

Since the 10E/10ER have exposed wiring, I would use a segment of the extension cord up and back, and switch both sides, cutting the ground at the switch and heat shrink the wires breaking out at both ends. The motor mount bars will ground the case and you can more easily remove, service the motor or replace the bearings later without disturbing the wiring. Every wire that goes to the motor would be part of that new extension cord.

I would use #12 wire for the extension cord even if you find they used 14 originally.

Everett

[everettdavis]

If you can place a strain relief it would be advisable always.

Everett

[jsburger]

Ok, that makes sense. Looks like a good easy spot to run the ground to.

I suppose a 65 year old switch might not be so desireable, so if this isn't original that's fine.

Was there originally some sort of strain releif on the power cord? Mine just runs right up to the back or the switch with no strain relief. That doesn't seem like the best plan. It seems like a wire clamp on the motor mount would be good.

I don't think there was any strain relief originally since the Model 10's were sold without a motor. It was up to the user. However a strain relief is absolutely a good idea. It is a bit hard to see in the picture but I just use a zip tie to the motor mount.