Delta Lathe switch Question

[owen bowen]

Have had a Delta 1440 Ironbed for years (I'll upgrade some day) that has the plastic switch above the motor. After babying it , it finally broke. Went out and got a 20 amp on/off switch and wired it up (white/white...black/black...green/green). Runs the motor but will pop the breaker when switching on. (it will run motor if plugged in with switch on).I have a limited knowledge of electricity (that stuff is sneeky...can't see it, hear it , smell it) so i'm not to comfortable moving wires around. Any ideas ??

[Dennis Ford]

You need a switch that is rated for motors (they are usually rated by HP). Starting (and especially stopping) motors is very hard on switches.

[Dave Wagner]

Normally you use a "Motor" start switch, they are heavy contacts and Higher amperage. You wire them them from side to side. usually the white and black hook to one side (source) and white and black to the other side (load). It probably has higher resistance in the contacts when switching, the motor start type switches are normally a faster make/break switch.

I just removed one from my table saw and put in a Safety Switch with a large paddle stop button. Nice improvement!

They are usually a bit more expensive ($20-40). but worth it.

[Bill Bukovec]

I have the same lathe and had the same problem.

Is the motor wired for 110 volts or 220 volts?

Mine is wired for 120.

I bought a regular switch that one would use for turning on and off your lights.

This switch has two screw terminals.

I connected the white wires to each other with a wire nut.

Then one black wire goes to one screw, the other black to the other screw.

If this doesn't make sense, let me know.

I will see if I can post a wiring diagram.

Bill

[Greg Just]

I replaced mine after a couple of years with a switch I purchased on sale at Rockler. It has been working fine for over 3 years.

[Bill Boehme]

... I have a limited knowledge of electricity ..... Any ideas ??

Yes, please don't mess with electricity if you do not understand what you are doing. You could electrocute yourself or someone else.

Now that you have been properly chastised, I would say that you wired the switch up wrong. The green wire should not have been touched -- it is a safety ground and does not connect to the switch -- it only connects to the metal frame. Since you bought a different type of switch than the original, you need to make certain that you are switching the motor leads to the line and not doing something else like throwing a dead short across the line. It is not good for the switch and not good for the circuit breaker.

One thing that is confusing me is that you said that you connected black to black and white to white -- surely you did not mean that you connected those wires directly together, did you? If you really did connect the black to black at the same switch lug and white to white at the same switch lug then I strongly suspect that when you are turning the switch ON, you are actually throwing a dead short across the line. This would explain why the breaker pops when you use the switch and runs fine when you just plug the lathe into the wall socket with the switch OFF. If your switch has two lugs, then the white wires should not be connected to the switch -- only to each other -- and the two black leads would go to the two lugs.


Normally you use a "Motor" start switch, they are heavy contacts and Higher amperage. You wire them them from side to side. usually the white and black hook to one side (source) and white and black to the other side (load). It probably has higher resistance in the contacts when switching, the motor start type switches are normally a faster make/break switch.

I just removed one from my table saw and put in a Safety Switch with a large paddle stop button. Nice improvement!

They are usually a bit more expensive ($20-40). but worth it.

I think that you mean a motor rated switch which will specify a horsepower rating in addition to the ampacity. A motor start switch is an entirely different animal. What you say is correct, but a toggle switch rated at 20A will probably work just fine if it has a snap action. In general, the HP rating of a switch is rated for half the current rating of a resistive load switch. The motor on the Delta lathe draws a FLC of about 9.8 A.

I would not make any assumptions about the internal connections based on the physical arrangement of the lugs on the switch -- what you stated might be the case most of hte time, but not necessarily all the time.


I have the same lathe and had the same problem.

Is the motor wired for 110 volts or 220 volts?

Mine is wired for 120.

I bought a regular switch that one would use for turning on and off your lights.

This switch has two screw terminals.

I connected the white wires to each other with a wire nut.

Then one black wire goes to one screw, the other black to the other screw.

If this doesn't make sense, let me know.

I will see if I can post a wiring diagram.

Bill

I agree with what you say. My Delta 1440 is 2004 vintage and only ran on 120 VAC. FWIW, I went inside the motor and brought out leads so that it could be run in either direction. It seemed like a good idea at the time, but I actually never do run it in reverse so basically I did it just because it could be done.

The original switch on my lathe gave up the ghost after about a year, but the replacement is still working.