Crompton Motor Wiring Help

[John Mitchell 9Participant @johnmitchell9]

Hello,

Can anyone help me wire up a motor please?

 

Here's some pictures of the bottom of the motor and a table that came with it.

 

This is to power an old Fobco pillar drill with original rotary switch.

 

I just need to know if I need a capacitor (or two and what specs?) and where I need to hook up Live, Neutral and Earth. Just one direction please, nothing else.

 

Thanks a million.

Photos:

1

2

3

 

Edited By John Mitchell 9 on 19/12/2019 19:46:38

[John Mitchell 9Participant @johnmitchell9]

[noel shelleyParticipant @noelshelley55608]

U1 and U2 are the run windings and need to be connected across the line (brown) and neutral(blue). S and Z2 are the start windings and dictate which way the motor will run. To reverse the direction swap S and Z2. The picture of the motor shows links U2 /Z2 and S /U1 This will work, But if rotating in the wrong way then link U2/S and U1/Z2. You ask about capacitors ! Are none fitted ? is there any sign there where any fitted ?

Happy Shristmas Noel

[Phil WhitleyParticipant @philwhitley94135]

You have two windings, start, and run, the run winding is U1 andU2, and the start winding is Z1 and Z2 both windings are connected across live and neutral, with the centrifugal switch in series with the start winding. Those copper links look wrong! First, remove the yellow wire from the terminal and test between the yellow wire and Z2, you should get continuity, indicating that the yellow is Z1. Next you need to find which terminals the centrifugal switch are across, so you will need to be able to open and close the switch by poking it with a screwdriver, or sliding the bob weight mechanism to the open position. It looks like Z2 may be one end of the switch, but you can confirm this with a multimeter. Once you have found the switch, you connect the live to U1 and Z1 and the neutral to U2 and one end of the switch, the other end of the switch is connected to Z2, Try the motor, it should run up to speed and run quietly. if it buzzes, but runs up to speed if you spin the shaft, it may need a capacitor, but if there is no signs of one ever being fitted, it is probably designed to be self starting. If it runs off load, but will not start on the drill, try a 4mf cap in series with the start winding and switch. Like this, but you will not need a run capacitor, and you may not need one at all. Hope this helps, and MAKE SURE IT IS EARTHED!!!

Phil.

[noel shelleyParticipant @noelshelley55608]

AND, the earth should be connected to a clean, sound point on the motor. Possibly one of the cover securing screws or bolts.

[Phil WhitleyParticipant @philwhitley94135]

Noel beat me to it, to reverse just swap Z1 and Z2 which changes the polarity of the start winding, and gives the rotor a push in the opposite direction. Good luck!

Phil

[noel shelleyParticipant @noelshelley55608]

From the diagram No3 your motor uses S instead of Z1 and the links on this basis are right. N

[Phil WhitleyParticipant @philwhitley94135]

I agree Noel, but I always check unknown connections , those links are definitely none standard, and you never know what has been messed about with! Having looked again at the links in their present position, the switch appears to be out of circuit?

Phil.

Edited By Phil Whitley on 19/12/2019 20:53:03

[Pete RimmerParticipant @peterimmer30576]

My Brook Crompton wiring sticker says swap blue and yellow to reverse. I guess it would have the same effect.

John, putting live and neutral to U2 and U1 will make it run. Doesn't matter which way round. To reverse the direction swap blue and yellow. Basically the copper links are in place of a reversing switch.

Edited By Pete Rimmer on 19/12/2019 21:01:11

[EmgeeParticipant @emgee]

Posted by Pete Rimmer on 19/12/2019 20:54:41:

My Brook Crompton wiring sticker says swap blue and yellow to reverse. I guess it would have the same effect.

Edited By Pete Rimmer on 19/12/2019 20:55:09

Correct, blue and yellow are the ends of the start winding.

Emgee

[Phil WhitleyParticipant @philwhitley94135]

If the yellow is Z2, then the switch is out of circuit. and connecting with the links in these positions will rapidly burn out the start winding. If the yellow is a link to the switch (S=switch?), and Z2 is connected to the other side of the switch behind the terminal plate, then the links are correct, but what are R and P for? would not be happy connecting this up without confirming the circuit with a multimeter!!

[Pete RimmerParticipant @peterimmer30576]

The switch and the start winding are in series so when the switch opens the circuit is broken regardless of which way round it's connected.

[Phil WhitleyParticipant @philwhitley94135]

So you are saying that the yellow is not Z2, but is a link to the C switch?

[Pete RimmerParticipant @peterimmer30576]

Yes, yellow is a link to the switch.

https://cdn.instructables.com/FBK/BW6B/HF23M68P/FBKBW6BHF23M68P.LARGE.jpg

Edited By Pete Rimmer on 19/12/2019 21:53:40

[Phil WhitleyParticipant @philwhitley94135]

Gotcha! It is right, I always err on the side of caution when I am advising someone else!

Phil

[John Mitchell 9Participant @johnmitchell9]

Gentlemen,

I thank you all for the excellent input. I had to read a few times to take it in but I can now confirm that the motor is wired up and works as it should. A few things I went through:

– I measured continuity between yellow wire and blue post. Indeed there was continuity.

– I removed the copper links as they didn't appear factory. I had to put them back as the motor would buzz but not spin, even after helping it wit manually spinning the pulley.

– Pete Rimmer, you are dead on with your suggestion. It is a reverse rotation linkage. I figured it after removing it first and comparing to the diagram. Not that others provided a lesser input. I am glad people take time to explain things rather than just give a shortcut. Now that I "get it", all makes perfect sense.

It's all there gents, but as usual, put in simple terms by people "who's been there done that" made it clear and easy to understand.

Again, many thanks. I'm very pleased I have a working drill again.

PS: No capacitors came with the motor. It doesn't seem to need them.

J

[John Mitchell 9Participant @johnmitchell9]

As my luck would have it, soon after wiring the motor up it started to bog down even under minor load. It appears to start and spin to only half of its intended speed of 2800rpm. Could running capacitor die prematurely or am I looking at something more serious here? I've not opened the cover to replace the cap because of its awkward location but will try to have a look Monday. Unless the board tells me otherwise? The motor was bought online and is one of the Far Eastern made units, supplied by a local business. It's probably only 2 months old. Again, any ideas are welcome and highly appreicated!

J

[noel shelleyParticipant @noelshelley55608]

IF it worked ok to start with but has now started to play up Do you have any garrantee ? If yes then return it to the supplier. If no garrantee then Remove the motor and note all wiring . Then if you have the luxury of a good multimeter with a capacitor function it's simple to read off the value and check the plate value. These will often be 20% tolerance. If reading is below spec then replace BUT note the voltage, may be 440v Before working on capacitors DO discharge it, ideally with a resistor. There may be 2 one for starting and another for run.

Noel

[Author]

Posts