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Motor issues

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John Milligan21/11/2015 21:26:37
59 forum posts
3 photos

hi guys, just collected a new, to me, Centec 2A, with vertical quill head and I have a motor question (am mechanical not electrical minded)! It has a Crompton Parkinson 0.25 Hp motor which is different colour to machine so assume it's not original. Vertical head was fitted to it and needs the overhead arm finished, so I assume only the vertical head was being used. Reading the lathes.co website it mentions the spindle will turn in wrong direction on one of the heads if there is no reversing switch fitted. Question is, can I fit a reverse drum switch to the motor if there are only three terminals on the motor? When I took the terminal plate off there was original sticker inside saying direction can be reversed by swapping terminals, so motor can run both ways, but is this an either or option? Thanks

Emgee21/11/2015 21:44:19
2610 forum posts
312 photos

Hi John

3 wires suggests a 3 phase motor which would be reversible by swapping over a pair of wires, are any details of motor voltage and current on the motor plate ?

Emgee

D.A.Godley21/11/2015 22:38:28
143 forum posts
41 photos

John,

I have a Centec 2B horizontal machine , to which I added the Vertical head , and I love it.

Since I have No knowledge of electrics, my ( late and much missed ) friend kindly wired a reversing switch, purchased from eBay , and sourced from China, to my motor which is single phase.

So, yes it can be done , just ensure a competent person does it for you.

David.

Edited By D.A.G. on 21/11/2015 22:39:20

John Rudd21/11/2015 22:47:48
1479 forum posts
1 photos

John, could you post up a picture of the motor or its data plate please?

Then a potential solution may be forthcoming....

T.B22/11/2015 02:26:46
54 forum posts
21 photos

I'm happy to be corrected, but from my experience i think you will find a 1/4HP motor significantly lacking in power on a Centec mill.

I'd look at this first as to be honest i think you will need another motor.

Congratulations on your purchase though , i have a Centec as well and think there great machines.

John Milligan22/11/2015 08:40:05
59 forum posts
3 photos

Thanks for replies, will try to take some photos and add later, but have to tidy house first as there are boxes of bits everywhere! TB I think I agree with you as lathes.co mentions 3/4hp three phase? Will have a word with second hand mc dealer I got it from and see if they have any history on motor etc, thanks John

Ivan Prince22/11/2015 08:41:59
6 forum posts

John

If you have 3 wires and your instructions are telling you you need to swap over two connections to change rotation , then you will have a 3 phase motor fitted to your machine

Have you 3 phase in your workshop.

Regards

Ivan

Robbo22/11/2015 09:19:56
1504 forum posts
142 photos

Sounds very much like a single voltage (400-415 volts) 3-phase motor, in which case you have several options:

Replace it with a single phase.

Buy a phase converter or 440 volt inverter and run it through that - Expensive

Do some surgery on the motor windings to convert it to dual-voltage and buy a 240 volt Inverter to run it. About the same cost as a new single phase motor.

More modern 3-phase motors are usually dual-voltage, 400/240 volt but still need a 3-phase supply.

The surgery necessary to convert the motor to dual voltage has recently been covered in this thread: **LINK**

It may of course turn out to be a peculiar single phase motor, but will not be reversible with just 3 connections.

Check on the motor plate, the phase type will be shown there.

BTW, the colour of the motor being different from that of the machine is of no significance, this is quite normal.

 

Edited By Robbo on 22/11/2015 09:22:26

john fletcher 122/11/2015 09:32:30
893 forum posts

You said the motor is a Crompton Parkinson single phase motor. I have just had a look at my motor note book and it says a split phase or capacitor start motor can be reversed by changing over wires BLACK and BLUE. I made a picture of the terminal block and there was three terminals A, Z and AZ. To make a split phase into a cap start remove the link between A and AZ and its place fit the capacitor. Others more knowledgeable than me on the Centec machine suggest you need a larger motor, so it maybe time to fit an inverter and three phase motor. John

David Clark 122/11/2015 09:37:41
avatar
3357 forum posts
112 photos
10 articles

A 1/4hp motor will probably be fine for the size of cutters you would use on a Centec. I thought the reversing switch was usually on the lower front of the machine but it has been nearly forty years since I used one. The switch reversed the direction of rotation by flicking the lever. This was a three phase machine.

Edited By David Clark 1 on 22/11/2015 09:41:15

Ajohnw22/11/2015 11:31:11
3631 forum posts
160 photos

According to lathes co uk it should be fitted with a 1/2 to 3/4 hp motor either 1400 or 2800 rpm. The higher speed motor might only relate to more recent versions. I would have said that even with morse 2 a 1/2hp motor is preferable.

Personally with a 6 speed gearbox built in I wouldn't bother going to 3 phase and an inverter but would wonder about fitting a single phase 2800rpm motor and would stick with 1400 rpm.

It's possible to buy fwd / off / rev switches. For instance

**LINK**

Really there should be a no volts release switch in circuit before these to meet modern safety standards however there will be older machines about where people have to remember to use the switch to turn it off if there is a power supply interruption.

The 3/4hp option is probably for when a 2,800 rpm motor is fitted. Lathes co aren't clear on that point.

John

-

Edited By John W1 on 22/11/2015 11:31:50

Edited By John W1 on 22/11/2015 11:37:16

john fletcher 122/11/2015 12:07:31
893 forum posts

Just seen an advert for BECO washing machines, its says now fitted with an inverter powered motor. Might be an idea to look out for a scrap one in say 5 years time. It would be interesting to see a circuit diagram and find out if it would be possible to re program the inverter for workshop use. Keep your eye open. John

John Milligan22/11/2015 17:08:21
59 forum posts
3 photos

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ImageFromAlbumInsertData|---%3Ca%20href%3D%22/sites/7/images/member_albums/150534/636326.jpg%22%3E%3Cimg%20src%3D%22/sites/7/images/member_albums/150534/636326.jpg%22%20alt%3D%22dsc_0113.jpg%22%20title%3D%22dsc_0113.jpg%22%20/%3E%3C/a%3E---|ImageFromAlbumInsertData

dsc_0111.jpgImageFromAlbumInsertData|---%3Ca%20href%3D%22/sites/7/images/member_albums/150534/636325.jpg%22%3E%3Cimg%20src%3D%22/sites/7/images/member_albums/150534/636325.jpg%22%20alt%3D%22dsc_0111.jpg%22%20title%3D%22dsc_0111.jpg%22%20/%3E%3C/a%3E---|ImageFromAlbumInsertDatadsc_0109.jpgHi guys, have created an album as required and here are the photos, many thanks for your help so far.

PS had to take the 1/3 hp motor off the Super 7 to get it home and it weighs at least twice this one!

Ivan Prince22/11/2015 17:56:15
6 forum posts

John

Thats a single phase motor you have so you should be able to reverse it you just need the connection diagram for the drum switch

Ivan

Emgee22/11/2015 18:00:36
2610 forum posts
312 photos

John

I think I can see a Blue conductor going to the Z terminal and certainly a Yellow conductor on AZ, to reverse the motor change these over. (Yellow to Z and Blue to AZ)

Emgee

Edited By Emgee on 22/11/2015 18:01:53

Ajohnw22/11/2015 18:15:13
3631 forum posts
160 photos

This page goes through the various option for wiring one of these for fwd/off/rev.

**LINK**

The same is true of other makes as well but the labelling can differ.

John

-

John Milligan29/11/2015 10:25:19
59 forum posts
3 photos

Thanks for the link, looking at your motor you have four terminals whereas I only have three so I think I can only reverse the motor direction by swapping wires each time rather than with a switch?

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