Does this magnetic starter look worth saving

This starter came with my Hendey lathe sn 26251 that I have another thred describing the tear down and cleaning. This might not be a realistic question to ask since your going by a couple of pictures but it's an Allen Bradley switch that looks mechanically sound. There is definitely a little rusted and corroded. The whole set up starts at a RPC to a AB push button (forward, reverse, stop) switch to the starter, to a drum switch, to the motor. The motor is 1 horsepower, 3 phase. Thanks for any advise.

I have some old ones, but not that old. That is a reversing starter.
Joe

I have a rotary phase converter and a reversing magnetic starter with push buttons on my Clausing lathe. It all works very well. It is an old solution that works as well now as when new, but my equipment was all new when I installed it around 1989. This is expensive stuff to buy new and a 110V single phase input VFD would be a better solution if starting over. You can still use your drum switch to run the low voltage Fwd-Off-Rev control logic on a VFD, plus you can have variable speed.

I can't say whether your starter can be restored, but it would be worth trying if you don't need to buy parts for it.

Larry

Not much to check out on a starter like that. Clean all the crap from it, check the contacts for wear, check the contact springs, check the mechanical interlock to make sure it works (free to move, locks out one side when the other is engaged) also the electrical interlocks on the side of the contactors and lastly, that the coil/magnet system works. Very likely the magnet faces will be rusted and hence noisy. Clean the pole faces with emery just enough to clean them. Do not file, grind or otherwise change the pole faces or you will never get them to be quiet. Rub the two haves together to kind of lap them in. Spray them with a light oil like WD-40 but NOT heavy oil or grease.

Tom

To add to TDegenhard's comment, put the emery cloth on a very flat surface, and move the steel across it with the grain of the laminations. If you go across, you will smear the laminations and then you will have problems.
Joe

That's a lot of switchgear for a 1hp motor. The pushbuttons should control the magnetic starter. At a guess, it failed at some point and someone has added the drum switch. I can't see why you would want both. I suspect the mag starter is the original, and I would try and keep it that way. If the coils work, some cleaning and it should work just fine. If the coils don't work, you can probably buy replacements, but they might be a tad hard to find.

Thanks to all for the helpful replies. I will take some more pics and Then disassemble to clean. It will be a bit before I'm ready to power it up but I will let you all know the results. Again, thanks.

Jeff

jnov36 said:

This starter came with my Hendey lathe sn 26251 that I have another thred describing the tear down and cleaning. This might not be a realistic question to ask since your going by a couple of pictures but it's an Allen Bradley switch that looks mechanically sound. There is definitely a little rusted and corroded. The whole set up starts at a RPC to a AB push button (forward, reverse, stop) switch to the starter, to a drum switch, to the motor. The motor is 1 horsepower, 3 phase. Thanks for any advise.

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Your description of the circut is a little vage - As I read it, the double contacts start a RPC - rotary phase converter.
Two AB push starts at the RPC- that sounds like the magnetic starters.
To an AB push start F/R/S - that sounds like a three button switch for motor reversing (cranes, garage doors, tools etc).
From the RPC circut it sounds like you go to a rotary switch on the lathe and drive its primary motor.

Thats a bit odd, because there is no reason to reverse a phase converter, however, I can think of a reason to use something that looks like this in a RPC circut.
We will go out on a limb and guess. Does one contact tie a start capacitor to the RPC and another pull in a run capacitor? Both the F and R push buttons would be normaly open, and only fire one coil at a time. Push F, and the start cap pulls in and gets the converter turning. If the normaly closed stop switch is not wired to the first coil, all you have to do is release it and it falls out. Then you push the "R" and the run cap pulls in and the stop (normaly closed) is wired to that circut and the switch keeps the second interlock engaged. That would be an OK way to do and RPC and would explain twin relays that are intelocked. A simple home built RPC rig might have a start button and a run button on the RPC, and the labels were never changed by the builder. Trick is you cant hold the run switch in very long or you let the smoke out of the start cap.

The drum switch makes sense for forward and reverse on the lathe motor becasue the loads are small. Just be sure you have proper overload protection (heaters or fuses).

I see a green tinge at some of the screws. Thats typical of copper oxidizing. Figure you will need to replace the wires, especialy if they are mult strand.

Before putting a lot of effort into this unit check the coil voltage and the amperage of the heaters. If the size is wrong for the voltage you want to operate the machine at, its probaly not worth the effort to find replacements, just get a newer set of starters thats up to code.

Looking at this again I think the starter is set up for 440v. That is what's labelled on the coil. I'll start looking for a vfd.

Ahall I'll try to explain the set up a little better. I am no electrician buy any stretch of the imagination. Also none of this was connected and running when I bought the lathe so I'm not 100% how it was connected. Incoming power goes into the starter box. Also connected to the top of the switch is the 3 button f/r/s switch, pictured below. It is the orange painted conduit coming out of the top of the box in pic 2. Separately there is a 3 position drum switch connected to the motor and old style Lima drive. I don't have a good pic but here is one of the motor/gearbox. It's hard to see but there a an orange conduit off the motor box, that is where the dorm switch is.

jnov36 said:

Looking at this again I think the starter is set up for 440v. That is what's labelled on the coil. I'll start looking for a vfd.

Ahall I'll try to explain the set up a little better. I am no electrician buy any stretch of the imagination. Also none of this was connected and running when I bought the lathe so I'm not 100% how it was connected. Incoming power goes into the starter box. Also connected to the top of the switch is the 3 button f/r/s switch, pictured below. It is the orange painted conduit coming out of the top of the box in pic 2. Separately there is a 3 position drum switch connected to the motor and old style Lima drive. I don't have a good pic but here is one of the motor/gearbox. It's hard to see but there a an orange conduit off the motor box, that is where the dorm switch is.

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Yep, I see the 440V call out in you photos on the coils. Thats as good a reason as any to stop on a motor starter that is marginal.
You can use a transformer to change the supply voltage for the coils, but the heaters are likely to be an issue and finding replacements will be a chalenge. So, if you have to use it, or just want to, you can.

If you decide to junk the starter, take some time to disect it and get a full understanding of the circut. Its worth understanding these divices should you become infected with old iron disease. I also usualy salvage the heater elements from starters. They dont take up a lot of space and Once in a while they come in handy on a new aquisition, but I still use a RPC to power my shop.



Now on to the fun- lets get that motor spinning

Start at the Lima drive. How is it wired, 220 or 440? Look at the little tag above the hole the wires come in. It looks like a wireing diagram.
I will assume you need 220, so wire the motor for 220 and bring out three good leads big enough for the amperage of the motor.


Then test the motor an make sure its not toast. Use your multimeter to verify simple stuff like no connections between the windings and frame and the winding resistance is about the same between the 3 input taps. Assuming that checks out, Put the Lima drive in high gear, wrap a string around the pulley and get the motor spinning with no juce. Be sure the string pulls free of the motor. With it spinning, hit it with 220V single phase and she should go ahead and spin up. It will be noisy and shut it down in after your satisfied she is up to speed. I have never tried this test with a gear drive in place so your reasults may very but it is a very convienent way to verify a motor is good before spending time, money and effort on junk. Its wise to work on the floor or clamp the motor down on the bench when doing this. Some like to walk.

Sounds like you thinking about the VFD route to 3 phase power. If so, follow the instructions that come with the VFD and set up some nice controls that are easy to use.

With a VFD the motor starters and drum switch go to the parts bin or junk. You wont need them to start the motor or switch directions.

We'll I went out to take another closer look at this and also a mind to check the motor out. The motor was wired for 220v. The starter looks like it was set up for 440v. Like you said Ahall, something doesn't sound right. I wonder if the lathe was was set up to run 440 when it was rebuilt during the war. The push button switch has 1944 on it and the lathe has a wartime production tag on it. Then at sometime later someone wanted to run it off 220v and bypassed the starter and added the drum switch.
I got some screwed up reading on the meter, was trying to check resistance but the wire connection were rusted up pretty bad so I think I'm going to cut the wires back a bit and recheck.
I have to say it's never boring rebuilding a 80 some year old machine. At some point I'll get this lathe to run.