Wiring assistance needed

[682bear]

I have just purchased an old Smith & Mills 20" shaper.

It has two motors on it... the main motor is a 5hp GE 220/440 3 phase. The smaller motor is a 1hp Howell Electric 220/440 3 phase... the smaller motor only drives the rapid traverse on the cross slide.

There are two Allen-Bradley contactors... I would assume one powers the main motor and keeps it running until it is turned off... the other powers the rapid motor and is a momentary switch. Both contactors appear to be identical.

Question 1: on the tags on the contactors the block labeled 'control voltage' is blank... the block labeled 'voltage' has 220 stamped in it. The block labeled 'amps' is also blank. Both have N36 thermal elements. What should the control voltage be, 220v?

Question 2: the seller told me that the machine was wired for 440v... but just looking at the diagrams on both motors, I'm not sure about that. I can't find any numbers on the wires, but looking at this tag...

...it looks like the lower voltage would have 4 sets of 3 wires connected, while the high voltage would have 6 sets of 2 wires connected. The diagrams for both motors are the same, and both motors have 4 sets of 3 wires connected... am I assuming too much?

Question 3: would this machine be too much to run on a 7-½hp RPC?

Question 4: are the thermal elements (heaters?) adequate for 220v service? The main motor tag states 13.7 FLA at 220v... the rapid motor tag says 3.18 amps at 220v...

Thanks- Bear

 

[rabler]

...it looks like the lower voltage would have 4 sets of 3 wires connected, while the high voltage would have 6 sets of 2 wires connected. The diagrams for both motors are the same, and both motors have 4 sets of 3 wires connected... am I assuming too much?

Envious. A shaper is on my list. As are too many other things.

That certainly sounds like it's wired for 220. Did the seller have it running when sold? Or was it sitting like it had been disconnected for a while? If you want to be certain, you could ohm out the windings, although not likely to give you more info. The rightmost image is the winding configuration. High voltage the three extra pieces are connected to extend the center Y. Low voltage the three extra (outer) windings are connected to form a second Y.

The normal recommendation for an RPC is 2x the motor HP so that may be a bit undersized, but there is some variation in that based on whether it is a hard starting load. You could try running it on that RPC and see how it does, motor startup is usually the issue.
Pictures of the contactors and associated wiring would probably be helpful in answering some of the other questions. Is there a transformer in the cabinet? Typically older machines used line voltage for the coils. N36 sounds like the right ballpark for a 5HP motor, but is seriously oversized for the rapids.

One of the guys more experienced with motor controls may have some better comments.

 

[markba633csi]

From your description it sure sounds like the motors are configured for 220v
You could probably get away with a 7.5 HP RPC- do you have that already or are you planning to buy one?
-Mark

 

[Nogoingback]

OK, all this flim flam about wiring is great, but where are the pics of the shaper?

 

[projectnut]

From your description I would also think the motors are wired for 220V. The N36 heaters can handle a maximum amperage draw of between 15.1 amps and 19.1 amps depending on the size starter they are used in. 15.1 amps is about the maximum draw for a 5 hp 3 phase motor wired for 220. Wired for 440 v it should draw half that amount. Since the heaters protect against excessive current draw the motor would long be toast before the heaters tripped if it was wired 440V

 

[benmychree]

OK, all this flim flam about wiring is great, but where are the pics of the shaper?

Yeah, without pictures, it does not exist. I think the 7.5 HP convertor would work, seeing as there is no hard starting load.

 

[682bear]

Envious. A shaper is on my list. As are too many other things.

That certainly sounds like it's wired for 220. Did the seller have it running when sold? Or was it sitting like it had been disconnected for a while?

The ad said it was under power, but had been disconnected and moved out before I arrived to pick it up. It obviously hadn't been operated in some time from the dust on the ways.

Pictures of the contactors and associated wiring would probably be helpful in answering some of the other questions. Is there a transformer in the cabinet? Typically older machines used line voltage for the coils. N36 sounds like the right ballpark for a 5HP motor, but is seriously oversized for the rapids.

One of the guys more experienced with motor controls may have some better comments.

There is no transformer in the cabinet...





Just 2 contactors...

From your description it sure sounds like the motors are configured for 220v
You could probably get away with a 7.5 HP RPC- do you have that already or are you planning to buy one?
-Mark

I already have the 7.5 hp RPC... I'd rather not upgrade unless I have to...

Here is the shaper...



Thanks!- Bear

 

[rabler]

Looks like a nice machine.

Pretty sure you’re working with a 220 machine, pretty much plug it in to the RPC and try it out. As I mentioned you probably want to downsize the heater on the rapids contactor.

 

[projectnut]

Looking at the picture of the starter it’s definitely wired for 220/230 volts. The coil is labeled 230 volts. If it was wired 440 the coils would burn out in seconds. Smaller heaters would be ok if you don’t plan to work it to it’s maximum capability

 

[markba633csi]

Looking at those contactor connections I would definitely re-do some of them; strip the wire back and re-attach the flakeyest ones
-M