RAS motor help.....may have screwed myself

[Matt Hutchinson]

Well, I managed to overlook something when recently purchasing a Rockwell/Delta 14" RAS. I thought everything was good to go. I checked the moving parts, the phase (it's 3 ph), and the voltage. I thought I was in the clear.

But now I am afraid I made a mistake. I don't know what happens if a motor is rebuilt, but I am concerned that the once dual voltage motor (220v/440v) is actually only 440v. I looked at the plate, and it had wiring diagrams for both 220 and 440, but in the dark lighting I neglected to see that further down, in the amperage info, the 220v numbers and amperage had been stamped with XXXXX. I was planning on getting a phase converter, but if it's 440v I am out of luck.

I thought I checked all the details, but now I think I may have an unusable tool that will be tough to sell. Is there a way to confirm if it's dual voltage or only 440V? Thanks.

Yours truly bummed out,

Hutch

[Tom Veatch]

You may evaluate my comments in the light that my experience with 3 phase equipment is about the same as my experience with walking on the moon.

With that in mind:

Are all the leads shown in the wiring diagram available in the junction box and identified. If so, I would assume, maybe incorrectly, that they can be connected/reconnected per the wiring diagram. If the only available leads are for the line connections, then I'd agree that it's probably a single voltage motor.

[Rob Russell]

At 440v, it's gonna be a 3-phase machine.

Based on the assumption that you have 220v 3-phase power available, you can use a buck/boost transformer to take the 220v 3-phase and bump it up to 440v 3-phase. Note that the amperage requirements at 220v 3-phase will be double what 440v 3-phase needs.

[Matt Hutchinson]

There was never any doubt as to the motor's phase. I knew it was 3 phase, and my plan was to get a rotary converter for the RAS in the short term, and then buy other 3 PH tools down the road. I just had no idea there could be different voltage markings in two different places occupying the same information plate. I just assumed that once I saw 220v/440v, that's what I was getting.

Now here's the most confusing part. The plate has the 220v and amps stamped out, yet there are only 3 leads to connect to. According to the wiring diagram on the plate, a 3 lead connection setup is only used for 220v. What the heck is going on? Is it even possible to connect a motor to 440v with only 3 leads? (I am using the word "leads", but that may not be accurate. There are 3 wires in the motor wiring box. As to what those 3 wires are connected to and what is going on inside the motor housing I don't know.)

I am so bewildered.

Hutch

[Chris Rosenberger]

Matt,
Could you post a picture of the plate, wiring diagrams & the wires in the junction box? The motor could have been rewound at some point.

[Jeff Duncan]

I've switched the wiring for several motors in my shop and having done so I can say fairly comfortably.... I know very little about motor wiring:D
Soooo, I would recommend pulling the motor and swinging it by your local motor shop, if you have several near you go for the oldest, dirtiest, crustiest, of the bunch. They'll be able to get you on the right track and if it indeed is only 440v can give you a price to re-wire it to 220v.
The other option as mentioned would be to use a transformer to get the voltage difference, may be cheaper than a re-wire.

good luck,
JeffD

[Rod Sheridan]

A single voltage 3 phase motor only requires three leads. (Phase A, Phase B, Phase C).

Dual voltage 3 phase motors would require 9 wires at a minimum. This would allow you to put the 240 volt windings in parallel for 240 volt operation, or in series for 480 volt operation.

Regards, Rod.

[Matt Hutchinson]

I can't believe I did this. Armed with what I thought was enough knowledge, I went out and spent money on an unusable tool. I just can't believe it.

I didn't realize that the plate was probably massed produced for every stinkin' motor, whether 220v, 440v, or dual voltage, and that the wiring diagram was not indicative of the motor's actual voltage. I am so embarassed.

Like they say, a little knowledge is dangerous. At least I will never make this mistake again. My only fear now is that I won't be able to re-sell it. I imagine that most every local woodworking place using 440v already has what they need. This sucks.

I suppose that if I can't sell it I could save up to get the motor rewired, but that's probably rediculously expensive. :(

Hutch

P.S. I am still a little confused though. I don't know why the wiring diagram doesn't show a configuration of only 3 leads for a 440v motor. I shows that only the 220v uses 3 leads, but it sounds like either voltage can use only 3.

[Rod Sheridan]

Matt, how many wires are in the terminal box?

It sounds like it was rewound for 480 volt.

You can use it with a phase converter, a 240/480V autotransformer should be fairly small and inexpensive if you really have a 480 V only motor.

If you let me know what the nameplate current is for 480V I'll let you know what size transformer you would need.

Regards, Rod.

[Ralph Barhorst]

Matt,

You only need three leads to connect the saw to either 220 Volts or 440 Volts. However, if it is a dual voltage motor, then the three leads must be connected internally to other leads and you must change those internal connections when changing from one voltage to another.

In order to determine if the motor is single voltage or dual voltage, you will need to remove the plate or cover from the motor.

Here is a diagram that shows the normal connection for a dual voltage three phase motor.


http://www.homemetalshopclub.org/news/may05/schematic.gif

Let me know if you have any other questions.

[Matt Hutchinson]

It is definitely a single voltage motor. I opened it all up, just to make sure, and there are 3 and only 3 connectors. I can't imagine it would be only 220v. It most likely is 440v, and the wiring may even be original, cuz the leads are insulated with a woven material, not rubbery plastic.

Also, it has an electric braking system added on to it, and these electric boxes are attached to the base.

Hutch

[Matt Hutchinson]

Sounds like I might be able to get this motor converted to 220V. Assuming that they have no problems, theshop I talked with should be able to re-lead the motor for around $200. This is by far the most economical solution. Unfortunately, if they windings don't cooperate, I may end up spending around $500 in order to get is rewound. I am keeping my fingers crossed.

Next Question: When a RAS arm locks at 45 and 90 degrees should I expect to have a smidge of play, like about 1/64th, or should it 'snap' into place and not move period? I took the turret arm off to look at the condition of the replaceable notched inserts, as well at the locking pin/plunger assembly. There is the slightest compression in the metal, and this may be causing the problem. Does your RAS have zero play? Thanks.

Hutch

P.S. I finally figured out what model it is.....old. :) It's an old style model 40-CL. The "L" means it has a longer turret arm than the model 40C, giving it a rip capacity of over 36". All of the replacement part are available, which makes me even happier about this purchase.

[Joe Jensen]

I have this version of the Dewalt, it's a 14". I a tiny amount of play that I could not eliminate entirely. Given the fence system I wanted to use couldn't handle anything but 90 degrees, I got mine perfect, and tightened the screws that adjust the column diameter...joe
http://i174.photobucket.com/albums/w99/AZEngineer/_NIK1423.jpg

[Greg Sznajdruk]

. Does your RAS have zero play?
.

Matt:

I think you have hit the single biggest frustration with RAS. I have a 1956 Dewalt and it will go out of calibration just sitting in the shop or so it seems.

I've been tempted to set it at 90 degrees and then braze the d%^$ thing.

If you want another RAS you can have this one for $100. It's just 500 miles from you.

http://sawmillcreek.org/showthread.php?t=86527

Greg

[Joe Jensen]

Matt:

I think you have hit the single biggest frustration with RAS. I have a 1956 Dewalt and it will go out of calibration just sitting in the shop or so it seems.

I've been tempted to set it at 90 degrees and then braze the d%^$ thing.

If you want another RAS you can have this one for $100. It's just 500 miles from you.

http://sawmillcreek.org/showthread.php?t=86527

Greg

Greg, my column base (the part the column slides up and down, and side to side in) has bolts that I can tighten to take the play out of the column. I just tightened mine all the way to make the diameter smaller so the column won't slide up and down, or side to side. I set mine 15 years ago and it's still perfect today...joe

[Rick Potter]

Even after moving, I just had to give my DeWalt 12" a little slap and retighten the arm...the movers used it as a handle. I check it with a square every once in a while and it is rock solid.

Rick Potter