Drum switch on 220v lathe motor.

Jonwick · Aug 21, 2020

I want to replace all of the contactors and other electrical stuff that I can’t even name, with a simple drum switch. Please look at the pics and tell me if i would be making a mistake or recommend a good drum switch.

On the motor connection, i show the wires that have 220v while lathe is running. When lathe is idle, all three have 120v. No numbers on wires from motor.

dalmatiangirl61 · Aug 21, 2020

Jonwick said:
I want to replace all of the contactors and other electrical stuff that I can’t even name, with a simple drum switch. Please look at the pics and tell me if i would be making a mistake or recommend a good drum switch.

On the motor connection, i show the wires that have 220v while lathe is running. When lathe is idle, all three have 120v. No numbers on wires from motor.
View attachment 297370 View attachment 297371 View attachment 297372

I think you are opening a can of worms by replacing contactors with a drum switch, especially if you are not too electrically savvy. I ran your part# and not seeing a match by P# in my inventory, or anyone else's on ebay. If you can provide dimensions, specs and coil voltage I can take a look and see if there is anything compatible in my inventory.

Homebrewblob · Aug 21, 2020

That’s a single phase motor.
So at minimum if you did use a drum switch the motor won’t actually reverse unless you let it spin down to a stop first also your second pic made my head so I would NOT be able to give you much advice

atomarc · Aug 21, 2020

If you gut the system and go with the drum switch don't forget you're going to need motor overload protection. Your current system shows a O/L relay which will gone if you dump all that stuff.

Why are you thinking about doing this?

Stuart

Jonwick · Aug 21, 2020

atomarc said:
If you gut the system and go with the drum switch don't forget you're going to need motor overload protection. Your current system shows a O/L relay which will gone if you dump all that stuff.

Why are you thinking about doing this?

Stuart

Because i cannot find a contactor to replace bad one.

Jonwick · Aug 21, 2020

Homebrewblob said:
That’s a single phase motor.
So at minimum if you did use a drum switch the motor won’t actually reverse unless you let it spin down to a stop first also your second pic made my head so I would NOT be able to give you much advice

Yes, the lathe is like that now. When i go from reverse to forward, if i did not let chuck stop, it keeps going same direction.

atomarc · Aug 21, 2020

Jonwick said:
Because i cannot find a contactor to replace bad one.

Have you checked eBay..you should be able to find a nice IEC reversing contactor with overloads that you could stick in there. That would be a better route than a drum switch. Having said that, if you can rig up some overloads for the motor then the drum switch would be a viable solution..but you must protect the motor.

Stuart

Newman109 · Aug 21, 2020

atomarc said:
Have you checked eBay..you should be able to find a nice IEC reversing contactor with overloads that you could stick in there. That would be a better route than a drum switch. Having said that, if you can rig up some overloads for the motor then the drum switch would be a viable solution..but you must protect the motor.

Stuart

i needed replacement contractors for my no-name 13 X 40 lathe when the control transformer burned up. I found everything that I needed on Amazon. I used a contactor for forward and another for reverse. It was set up that way originally.
Besides using a drum switch to control the motor and losing motor protection, the OP would be running al of the motor current through the drum switch, I'd use contactors that are controlled by the drum switch instead.

SomeoneSomewhere · Aug 21, 2020

Contactors are entirely a commodity part. As long as you know:

Coil voltage
Number of poles and type (e.g. some have auxiliary NO or NC for controls and interlocking)
Current/power rating

... you can replace it with a new part from probably 10+ reputable manufacturers.

Pull it out and get us some good pictures and we should be able to find something.

jim rozen · Aug 23, 2020

Not for nothing but that looks like an awful lot of control electrics for a half hp single phase motor.

Jonwick · Aug 23, 2020

jim rozen said:
Not for nothing but that looks like an awful lot of control electrics for a half hp single phase motor.

Look closer, 1-1/2hp, but i agree, it looks like a lot. I figure, the contactor that is bad turns on electric. The other two are forward and reverse.

Jonwick · Aug 23, 2020

SomeoneSomewhere said:
Contactors are entirely a commodity part. As long as you know:

Coil voltage

Number of poles and type (e.g. some have auxiliary NO or NC for controls and interlocking)

Current/power rating

... you can replace it with a new part from probably 10+ reputable manufacturers.

Pull it out and get us some good pictures and we should be able to find something.

View attachment 297525

SomeoneSomewhere · Aug 23, 2020

OK, you need 3 poles, all normally open, sized for switching a 1.5HP 240V single phase motor, 24VAC coil voltage.

This is an IEC style one: https://www.automationdirect.com/ad...tactors_(3-pole)/12_amp_(ac3)/cwc012-10-30v04

It looks like it is a pretty close match size-wise, although it's unlikely for the bolts to match up. You also get a fourth contact that you can leave empty.

Jonwick · Aug 23, 2020

SomeoneSomewhere said:
OK, you need 3 poles, all normally open, sized for switching a 1.5HP 240V single phase motor, 24VAC coil voltage.

This is an IEC style one: https://www.automationdirect.com/ad...tactors_(3-pole)/12_amp_(ac3)/cwc012-10-30v04

It looks like it is a pretty close match size-wise, although it's unlikely for the bolts to match up. You also get a fourth contact that you can leave empty.

Mine has 4 rows of contacts plus the 2 contacts on the bottom, one each on two opposing corners. You can see the red wire jumping from a top contact to a lower one in pic. The lower ones are the contacts coming out of the 24 volt coil.

Jonwick · Aug 23, 2020

Newman109 said:
i needed replacement contractors for my no-name 13 X 40 lathe when the control transformer burned up. I found everything that I needed on Amazon. I used a contactor for forward and another for reverse. It was set up that way originally.
Besides using a drum switch to control the motor and losing motor protection, the OP would be running al of the motor current through the drum switch, I'd use contactors that are controlled by the drum switch instead.

I guess the big problem is me. If I can’t find the exact replacement, i do not know how to wire it.

Newman109 · Aug 23, 2020

My entire electrical panel burned up do to a failed control transformer. It sent 240 V to all of the 120 V contactor coils and left me with a smoking mess. My lathe used 240 V for the motor and 120 V for the contactor coils.

Wiring diagrams for lathe electrical panels are common on the Internet. I found a number of them. I don't dare ask you for the brand of your lathe, but if you look around on the 'Net, help is available.

Generally speaking, assuming that you are using a 120 V control transformer, the 120 V goes through the drum switch to operate the forward or reverse contactor. They would be interlocked as a set to prevent accidental simultaneous operation. That would switch the 240V to the motor as needed. There would also be a 120V on-off contactor and possibly a jog contactor, but that's really not needed.

jim rozen · Aug 23, 2020

looking *very* close here, it says "1/2 HP" on the nameplate.

SomeoneSomewhere · Aug 24, 2020

Jonwick said:
Mine has 4 rows of contacts plus the 2 contacts on the bottom, one each on two opposing corners. You can see the red wire jumping from a top contact to a lower one in pic. The lower ones are the contacts coming out of the 24 volt coil.

I think the top terminals for that are just used as a junction. The only difference with this new one is that the red wire is inside the contactor body, not outside it. You can ignore it.

Drum switch on 220v lathe motor.

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