Need help wiring a new switch in my Enco 9x20

ferlum

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Hi all. Hoping someone smarter than me can help me out here. The spindle switch in my Enco 9x20 had been giving my problems for a while so I decided it was time to replace it. I ordered a new switch from Grizzly hoping it would be the same. Turns out maybe it's not. At the least, their 9x20 is wired differently in that it has two capacitors where my lathe has one.

I attempted to duplicate the wiring of the original switch, but when I tried to turn the lathe on it tripped the circuit breaker so clearly I'm doing it wrong.

I'm not electronically inclined so figure it's time to get help.

I'll add some pictures here of the old switch connections (one wire is broken off the old switch as shown in the "old switch rev side" image (which is why the switch was failing, the plastic was falling apart. When I took the old switch out it fell apart completely).

I drew a diagram of how the old switch was wired ("old switch wiring").

Also adding pictures of the wiring diagram inside the lathe, the diagram from the Grizzly manual, and the new switch connections.

I'm sure this is very simple for someone who knows what they're doing. If you could tell me which wire to attach to which terminal on the new switch I'd be grateful.

If more information is needed please let me know.

THANKS!!!

diagram.jpg

grizzly wiring.JPG

new fwd side.jpg

new rev side.jpg

old fwd side.jpg

old rev side.jpg

OLD SWITCH WIRING.JPG
 
The old and new switches might not be connected the same internally. You are going to have to sit down with a multimeter and map both switches to make learn what the internal connections look like as you run the switches through their positions.
 
The old and new switches might not be connected the same internally. You are going to have to sit down with a multimeter and map both switches to make learn what the internal connections look like as you run the switches through their positions.

I can do that. Although I'm not sure how to map/learn the contact that's broken off the old switch. I was hoping someone smart could look at the Grizzly wiring, which uses this switch, and apply it to my lathe. I think I could come close, but that extra capacitor in the Grizzly diagram confuses me.

I'm mechanically inclined but electronically incompetent. :grin:

I even thought about sitting down with the new switch, a small dc motor and power supply and mapping it out that way. But then I wouldn't know what to do with the capacitor.
 
I prefer a drum switch myself.
https://www.grainger.com/product/DAYTON-Maintained-Reversing-Plastic-2X441
https://www.ebay.com/itm/60-A-Drum-...e=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649
Neither is that expensive, relative to the metal cased ones that show up in the used markets. This type of switch works for single or poly-phase motors. The rotary switches vary from switch to switch. Confusing, even to me and I've been in the field for more than 50 years. BTW, it's electrical, not electronics. There's a world of difference in the two.

The motor has two windings. One a run winding, the other a start winding. Reversing the connections of one or the other, doesn't matter which, will start the motor reversed. You must not reverse both, and reversing takes place only at or near zero speed. Reversing at speed (plugging) dosn't work on single phase motors.

According to the first drawing, showing factory connections, there are four leads. An ohmmeter is the easiest to use. A test light will work as well. Find a pair of wires that show continuity. One pair will show stable, the other pair a tapering over time. That pair is the start winding with a capacitor and the centrifugal switch. I would bet on the pair 2 and 3 (5 & V) being the start winding. Don't hold me to it for a power up test, though. Measure it!!!

Next, you want to find the switch contacts that reverse. They connect one way forward, the same contacts swap in reverse. Again, you'll need the ohmmeter to see this. And a paper to write down the results. One pair will make up in either direction. There are two others that will swap on direction. Once you have these points, just go by the drawings you have posted.

I don't like the colour file (Nr 2), personally I do better with a ladder diagram. But then I'm old and don't follow Japanese or Chinese diagrams that well. Nor like them. The first one is the most useful. Sorry... ... The coloured wires will also vary from machine to machine. Hope I helped you a little getting your machine back up.

Bill Hudson​
 
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One difference I see right off the bat: the old switch is strapped differently than the Grizzly drawing. Do you have access to the original diagram for your machine?
Don't worry about the extra cap. A minor detail.
mark
 
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Also, when you wired in the new switch did you strap it like your old one? I'm thinking Jim is correct and the two switches are different internally-
not to worry we can figure it out
On the first diagram (your original motor) it looks like 5 and 6 are the start leg (with the start cap in series) and U and V are the run winding.
I'll need to study the Grizzly drawing for a while to match that with your original.
mark
edit: I found a diagram that might help: It has more terminals than your switch but the principle should be the same:
rotarysw1x.jpg
 
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So first thing is to determine if this truth table matches your new switch or not: put switch in forward and see which terminals connect. Then put switch in reverse and do the same. Redraw the truth table if necessary. Then most of the battle is won.
mark
 
Thanks Bill and Mark!

Bill: When you say "One pair will show stable, the other pair a tapering over time", do you mean a drop in resistance?

Mark: Yes, I did strap it like the old one. I used short wires with crimped terminals in place of the straps. It does seem to be different internally. Looking at the Grizzly diagram now, it seems like terminals 1, 5, 9 are strapped; and terminals 3, 7, and 11 are strapped. Am I reading that correctly? That should be showing the switch I have, as it's the part number called out in that manual.

The diagram for my machine is the first picture above ("diagram").

When I get home tonight I'm going to take a look to determine if I have a run cap or a start cap, in case that matters. I should be able to tell by the labeled values.

I will check the new switch against that table. I'm assuming "X" means closed. So in the example above, with the switch in "FWD", I'd have continuity between terminal 1 and every terminal with an X? Just want to make sure I'm reading that correctly too.

Sorry for the dumb questions. Appreciate your help!
 
No dumb questions here- I believe the switch won't match the truth table and I also believe it's a custom Grizzly switch. BUT, I believe we can still use it.
Yes the X means closed. Let me know what you find with your continuity test. I think we will end up strapping across the power side of the switch like the Grizzly G4000 and we will also add two straps or wires on the motor side of the switch. Then it should work. Fingers crossed LOL
mark
ps 5 and 6 from the motor should show a tapering resistance (from low to high) like Bill mentioned, that indicates the start leg. Reverse your test leads and you should see it each time.
pss Oh and, the X means (or should mean) only continuity on that pair. Like for example 1 and 2 only, 5 and 6 only, etc.
psss You might also see a pair(s) which has continuity both forward and reverse. Take careful notes, double check your results.
 
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Hi Guys,

Is it possible that the switch is simply rotated by 90 degrees ?
 
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