Author Topic: Bridgeport 2 speed motor wiring  (Read 36665 times)

Offline mebilloz1

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Bridgeport 2 speed motor wiring
« on: October 06, 2023, 07:00:14 PM »
Hi all

I was going to reply to an old thread (Bridgeport J Head Pancake Motor) but the robot said better with a new one.  Suspect "awemawson" might have this answer close to hand.
So I just acquired an old Bridgeport by adcock-shipley.  Went to power it all up and the drive motor sent out the magic smoke before tripping the fuses.  Pulled in apart and the flying leads from the windings to the 2 speed rotary switch have the insulation literally falling off them - All wires were the same colour, and the few markings that were on them, fell off as it was disconnected from the rotary switch.

The copper windings are find based off the impedance readings.
I have attached 2 pieces of '3 core flex' to the windings and created the table of resistances across the various connections.
My question: Can anyone suggest which wire corresponds to what original label (A2, A3 etc)

Bill (from Australia)


Offline awemawson

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Re: Bridgeport 2 speed motor wiring
« Reply #1 on: October 07, 2023, 02:54:57 AM »
Bill I’ll see what I can find, but my head’s not in a good place at the moment. (Had a nasty bout of shingles and not come out of the far end yet) Not been able to do anything in the workshop for a couple of months.
Andrew Mawson
East Sussex

Offline John Rudd

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Re: Bridgeport 2 speed motor wiring
« Reply #2 on: October 07, 2023, 06:19:51 AM »
The 2 speed motors are based on a Dhalander scheme…

The low speed is given by all the coils in series and high speed in parallel.

Identify each phase, you should have 3 wires for each, 9 in total… for a motor running off a 3 ph 415 supply…
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Offline ddmckee54

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Re: Bridgeport 2 speed motor wiring
« Reply #3 on: December 20, 2023, 05:55:13 PM »

Did you ever get this figured out?

From what I can figure out from my old Allen Bradley industrial controls catalog, you're going to have to get some motor info to be able to figure out how to connect this.

How many wires did you have going to the 2-speed switch, it looks like it should have been 6 wires.

There are a couple of different motor configurations that could account for the winding resistances that you measured.

Those readings suggest that you do not have a 2-speed separate winding motor, but rather a 2-speed consequent pole motor.  The problem is that a consequent pole motor looks like it can be configured for constant torque, or variable torque, or constant horsepower.

Too many irons, not enough fire.