Bridgeport spindle motor still ok ?

Hello,
perhaps you can help me. I am from germany and i have bought a textron bridgeport milling machine of 1976 with german writings on the plates. So it seems to be a conversion for germany. Misfortunately all the electic components were removed from the machine. Everything seems to be complete and in good condition but i dont know if there are electric defects.
So first i wanted to check the spindle motor if it is still ok. On the motor nameplate there is written normand electrical co. ltd. london, 380/420 Volts, 3 Phase 50 Hz,Frame 7, 2,0/1,0 HP, 3,8/2 amps, 2700/1420 RPM, rating cont ins, type sc e.
3 blue and 3 black wires hang out of the motor. None of them has conductivity with the housing, thats good. I found 3 pairs of a blue and a black cable which seem to be connected together inside. I think these are the 3 coils u,v,w, thats also good. So everything seems to be ok up to now and so I expected that this motor is a 3 phase asynchron motor but then the trouble started: 2 of the 3 coils have 7,6 ohm but the third coil has 13,4 ohm this seems strange to me. And all of the 6 cables have conductivity to the other cables which also seems to be strange to me.
I have only little experience with electiric motors, can anybody tell me if this motor is still ok or does it have a electrical defect inside?
All help is welcome, thank you in advance. Best regards Paul

Hello again,
a guy now told me that motors of milling machines usually are connected in the dahlander way?? or are dahlander motors?? or something like that with the keyword dahlander. This dahlander thing gives the possibility to operate the motor at two speeds and the higher speed is the lower speed x 2. A bridgeport milling machine has these two motor speeds where the higher speed = 2x lower speed.

What do you think and do you know how i can check my dahlander???? motor if it is still ok or if it has an electrical damage?

Regards paul

Take a look this should help explain it:
Dahlander pole changing motor - Wikipedia

Do not be inclined to think this is a two speed motor. IT IS NOT a two speed. There is the control labeled HIGH and LOW, what that means is the two speed back gears will turn the spindle reverse direction if you do not switch the control to LOW, meaning low gears are being used and the motor needs to turn in the reverse direction for the spindle to turn in the correct forward direction.

I short HIGH and LOW only reverse the motor direction, rpm is the same.

No numbers on those wires, look inside the junction box at the motor to see in the motor wires are numbered. Then mark the leads accordingly.

the OP's first post says the motor plate lists the motor at two different RPM's. I would tend to think it is a 2 speed motor. I can't help with the wiring, but you'll need a drum switch, for low fwd, hi fwd, low rev and hi rev.

The OP doesn't know it, but there is a BP forum.
JR

greggv said:

the OP's first post says the motor plate lists the motor at two different RPM's. I would tend to think it is a 2 speed motor. I can't help with the wiring, but you'll need a drum switch, for low fwd, hi fwd, low rev and hi rev.

Click to expand...

Another clue is two winding sets with two different resistance readings. That seems to describe a two speed motor.
So too, six leads..

It is a two speed motor. Very common on non-USA BP's, and on many USA clones. I've seen a few BP's in the USA with two speed motors also. Dahlanger motors do not simply switch between two different winging sets. You need the specific switch to switch both the speeds and direction.

Hello and thank you for your replies. Misfortunately i did not see that there is a bridgeport forum, otherwise i would have postet it there.

At least for european readers this could be interesting because here allmost all lathes, milling machines, drillpresses etc.) have a 2 speed motor. It is not just a normal 3 thase asynchron motor as i first thought, it is always a dahlander motor which is triangle double star connected.

There are dahlander switches but i think you can use other switches with 0,1,2 position, too. But you have to connect it to the dalander motor in triangle double star connection.

Misfortunately i have not enough time because of family, work....and there is nothing useful written on the german www about this theme but i will continue and hopefully i can soon post all the necessary knowledge about this mystherious theme on the bridgeport forum.