VFD Help! Myford 3 Phase Brook Crompton Parkinson motor.

[Weston MWParticipant @westonmw]

Hello Model Engineers,

I'm looking for some advice regarding a 3 Phase Brook Crompton Motor. The motor is from a Myford ML7RB on an Industrial Cabinet.

I recently purchased a Weg CFW300 VFD and have successfully set it up running a Tec 3 Phase Motor for an emco machine. However the Brook Compton motor i would like to use on the myford (see attached) has a terminal setup im not familiar with. In my (limited) experience, I have set up Tec Motors that are configurable to Star or Delta using the connecting bars in the terminal housing. But this motor does not have that setup.(See Pics Below)

MMB534BS1F282BV

W 370

RPM 1425

V 380/440 – 220/250

A 1.2 2.1

PH 3 HZ 50 RTG.CR

INS.CL F AMB *C Max

BS5000/11

If anyone could offer any advice on the following:

A) is this motor suitable for a VFD?

B) What configuration is this motor, Star or Delta? I will be running the VFD from household single phase supply.

C) How would i go about configuring it to Delta, will it require the motor end sheild fan cover to be removed?

Many thanks in advance for your help.

Paul (Long time subscriber to MEW, not a Model Engineer….yet!)

Edited By Weston MW on 31/05/2022 12:40:50

[Weston MWParticipant @westonmw]

[peak4Participant @peak4]

I think I can see the shadows of two other wires on the N terminal.
If that is the case, have a look at This Post on Mad Modder
https://www.madmodder.net/index.php?topic=3420.0

Bill

[Clive FosterParticipant @clivefoster55965]

These are copies of the Brook Gryphon connection diagrams from an official data sheet. Publication 9 / 100M / 2 / 70, reprint date 1970.

Sorry about the yuck green colour, presumably chosen to make copying difficult on then current photocopiers.

Its likely that the extra connections needed for 220 V, delta, operation are on the underside of the connection plate. Many years ago I encountered several motors made that way but I cant recall the breed. Presumably engineered to avoid having to re-design the motor bell housing to accommodate more screw tags and linking bars in modern fashion.

Clive

[Ian ParkinParticipant @ianparkin39383]

As bill said above there looks to be 3 wires on the N terminal one at 12 and one at 11 o’clock

remove the 3 wires from the N terminal and wire as the diagram above on the right hand diagram

[peak4Participant @peak4]

Just chucked a quick diagram together in Visio, based on the cover plate's photo in that link in the earlier post..
If anyone else has any useful diagrams, the album is available for member uploads

Bill

Edited By peak4 on 31/05/2022 13:40:13

[peak4Participant @peak4]

Posted by Ian Parkin on 31/05/2022 13:28:44:

As bill said above there looks to be 3 wires on the N terminal one at 12 and one at 11 o’clock

remove the 3 wires from the N terminal and wire as the diagram above on the right hand diagram

If you're going to do that, just make sure you buzz them out and label what came from where, as it's possible to reverse a single winding.
This isn't the same as reversing a phase feed in to reverse the motor's rotation.

Bill

[Weston MWParticipant @westonmw]

This Forum is incredible!

Thanks all so much for the quick replies. Im at work now but will digest this info this eve and respond fully.

Thanks so much for the help..

Paul.

[Ian ParkinParticipant @ianparkin39383]

Generally on those brook motors the colours for the sets of windings are the same colours so a1 and a2 will be red b1 and 2 will be cream(yellow) and c1 and 2 will be blue

Edited By Ian Parkin on 31/05/2022 14:43:12

[Morgan SweetParticipant @morgansweet]

Paul, I have the same motor running from the same vfd on my Myford 7 and have wired it for delta/mesh as shown above by Bill Peak4 with a protective earth connected to the motor terminal earth with continuity to all metal parts of the lathe and all is ok.  

I also added a potentiometer with on/off and fwd/rev switches as per the easy start guide.

Easy Start Guide – WEG CFW300 Frequency Inverter (inverterdrive.com)

Edited By Morgan Sweet on 31/05/2022 15:00:47

[Weston MWParticipant @westonmw]

This is starting to make a lot more sense. With the diagrams and links posted and the information provided I feel confident i can tackle this safely now and also happy i dont have to purchase a new motor!

I seem to have a growing collection of Single Phase Motors as I switch everything out to VFD!

I'll drop some detailed progress pictures in this thread over the coming week or so for anyone in the future who may stumble across this needing the same advice.

Can't thank you all enough.

Paul.

[Paul WestonParticipant @paulweston75534]

[Paul WestonParticipant @paulweston75534]

Many thanks for all the help. Managed to get it wired up to the VFD and it works perfectly.

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