# Need New Contactors



## dynastymsports (Feb 15, 2019)

Hi All-newbie here, rescued an older ENCO 12 X 36 from its rusting place on an exposed loading dock of a business nearby.  I replaced all of the buggered gears, shafts and bearings and wired it up to 220v single phase.  There was a purple (maybe blue) wire left loose in the motor hookup box and long story short, I managed to get it against the black lead coming in (110v line) and welded the contacts in not one, but both of the contactors. So now I need to replace the Riken RAB-18N units which seem to be obsolete with something more up to date.  Anybody want to take a stab at where I should try?  The motor ran fine in forward and reverse via the drum switch until I stepped in the kaka. The thing that throws me a little is the terminal markings which are on the top:    R/1  S/3  T/5   7

                                                                                                                  bottom:    U/2  V/4  W/6  8 

There are two other wires connected to top back left marked 7 and bottom right front marked 2

I believe it is a 3-pole with 110v coil but I've got to figure out if "normally closed" and "normally open" means contacts are either open or closed with an energized coil. I'm assuming "normally closed" means contacts are closed with the coils unenergized, but you know what you make when you assume something, right? Anyhow, any insight would be welcome and appreciated.


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## markba633csi (Feb 15, 2019)

Yes NC and NO means with coils unenergized, usually.
3 pole contactors with 120 volt coils should not be too hard to find- you may not be able to find the exact size or mounting holes though since those machines were made quite a while ago
Mark
ps here is some Enco stuff which may be helpful:


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## mksj (Feb 15, 2019)

Typically the motor terminals are NO, there is usually an extra set of terminals the are NC which are used for the interlock for the solenoid (i.e. when one is energized it prevents the other contactor from operating). The terminals for the input power are R, S, T, the 1,3, 5 are just the numbers for those terminals. The motor terminals are U, V, W, the numbers are 2, 4, 6 are the terminal. There should also be a motor overload relay attached to one of the contactors, but maybe not in these older lathes. There are many configurations for the contactors as far as terminals and NO/NC and you may have additional terminals for single phase. You might take some photos so we can provide further comment.


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## dynastymsports (Feb 15, 2019)

Thanks to you both for your input-now I'll have to digest some of this.  This is a mid-eighties machine so there is, in fact, no third relay for overload.  And I do believe MKSJ is correct about the NC being the interlock as I could hear one contactor clicking and then the other when I shifted the motor control/barrel switch from forward to reverse. (This was, obviously, before I welded the contacts together)  I'll post some photos as soon as I figure out how to get them onto my computer (it's been awhile).  Thanks again.


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## markba633csi (Feb 16, 2019)

It would be good to find out where that purple (or blue) wire is- there shouldn't be any loose wires
How much electrical experience do you have?  Do you own a multimeter of some kind?
M
ps if you remove any wires be sure to label them


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## dynastymsports (Feb 16, 2019)

markba633csi said:


> It would be good to find out where that purple (or blue) wire is- there shouldn't be any loose wires
> How much electrical experience do you have?  Do you own a multimeter of some kind?
> M
> ps if you remove any wires be sure to label them


I know enough not to stick a fork in an outlet while standing barefoot in a bathtub full of water...no, seriously, I've got a reasonable idea of how electrical devices work and how current flows.  I just did a dumb thing with that one wire, which, according to a schematic I later got from either Grizzly or Jet, for a machine pretty much like mine, the purple/blue wire is supposed to be terminated and not attached.  Because this wire had a ring terminal on it, I thought it was supposed to be hooked to something.  I got the lathe in disrepair and disassembled, so I was fishing around with it and proceeded to do a little welding.  I've located two new Chinese contactors that I think will solve the issue.  I do have a DVOM and I've got a reasonable idea about how to check things out. I've taken pictures of each of the contactors and how the wires run to them as well as made a rough sketch of the schematic so, hopefully I won't make any more mistakes. Thanks for your input


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## markba633csi (Feb 16, 2019)

OK sounds good


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