Advice regarding coolant pump please

[CaptainPugwash]

Hi, the 3 phase coolant pump on my recently acquired early 80s Boxford lathe doesn't work, does anyone have any tips what to investigate first/ common problems?

The switch will turn and click into various positions without a dicky bird from the pump, which is more of a rotating plastic paddle.

Tried it with lathe on and off, anf in and out of the tank.

Got new coolant sat ready!


Thanks for any pointers

 

[CaptainPugwash]

 

[CaptainPugwash]

 

[Martin-Sy]

Check for blown/tripped fuses/breakers if it has them.
Do you have a test meter? .....
Then check that the switch has continuity when on.(and not when off)
If all those OK, Take the cover off the motor and check for lose/broken connections.
Check that none of the motor windings are open circuit.

Does it hum when on? - May be mechanically seized.
Are you on mains 3 phase or running on an inverter/converter?

 

[CaptainPugwash]

Check for blown/tripped fuses/breakers if it has them.
Do you have a test meter? .....
Then check that the switch has continuity when on.(and not when off)
If all those OK, Take the cover off the motor and check for lose/broken connections.
Check that none of the motor windings are open circuit.

Does it hum when on? - May be mechanically seized.
Are you on mains 3 phase or running on an inverter/converter?

Thanks

3 phase mains, no inverter

It isn't humming, and I don't think it's mechanically seized

The fuses i can see aren't blown
I have reset the breaker

Going to take the cover off the motor now and need to get a battery for my tester but just found a loose wire,
Think I'll have to get a wiring diagram, I only have the general 'know your boxford' book

 

[m_c]

Coolant pumps aren't exactly complicated in terms of wiring.
Check you're getting power to switch. Power out of switch. Power in/out of whatever if any protection fitted, and power to the actual pump.

 

[Matrixx]

does the contactor pull in? have you reset the overload device?

 

[Agroshield]

Disconnect the cable at the switch end (leave the pump end connected). Wire into a red four pin plug. Plug in. Switch on. If it runs, it is something uphill of the pump. If not, the pump is NS.

 

[500e]

Remember 3 phase is 440 volts AC not good if you get across 2 phases.
If you feel confident and have a 1/2 decent meter with sensible leads, 1 probe to earth the other check phase wires 1,2,3, you should have a nominal 230V on each .
Be careful

 

[Wedg1e]

I'd be wondering whether that Kraus & Naimer-style switch is wired correctly, their terminal designations can be confusing.
Of course if it's original wiring and never been touched, it shouldn't be a problem...

The 'rotating plastic paddle' design is common to coolant pumps.

 

[addjunkie]

Take terminal cover off at the pump, switch on check for volts. If yes motor, if no follow back towards the supply. Check simple things first

 

[CaptainPugwash]

Remember 3 phase is 440 volts AC not good if you get across 2 phases.
If you feel confident and have a 1/2 decent meter with sensible leads, 1 probe to earth the other check phase wires 1,2,3, you should have a nominal 230V on each .
Be careful

Hmmm I seem to be getting 16v on everything, including the motor

Haven't found a wiring diagram yet
Haven't tried wiring a plug direct from the pump motor yet

 

[m_c]

Hmmm I seem to be getting 16v on everything, including the motor

Haven't found a wiring diagram yet
Haven't tried wiring a plug direct from the pump motor yet

What voltage do you get measuring between phases?

 

[500e]

I presume the main motor runs if so measure the incoming phases to earth
You do have a good don't you
Or between phases 440 volts or there about any 2 should give this sort of voltage, if that shows OK trace the pump wires back to SW check both sides of it again, earth to phase 240ish accros any 2 430 ish.
16v sounds like poor earth
As a check just follow the wires from pump
Just a thought there are no safety lick switches you have have opened on cabinet doors

 

[CaptainPugwash]

What voltage do you get measuring between phases?

0


Cheers

 

[CaptainPugwash]

I presume the main motor runs if so measure the incoming phases to earth
You do have a good don't you
Or between phases 440 volts or there about any 2 should give this sort of voltage, if that shows OK trace the pump wires back to SW check both sides of it again, earth to phase 240ish accros any 2 430 ish.
16v sounds like poor earth
As a check just follow the wires from pump
Just a thought there are no safety lick switches you have have opened on cabinet doors

The motor runs and will reverse

I found a loose wire but think I'll need a wiring diagram but doubt I will find one for this set up...
The earth isn't loose though

There were no safety cut offs I can see/ followed the wires around



Thanks

 

[500e]

Some where the 3 phases going to the motor no longer have voltage on them where does the loose wire go. Remember 3 phase can kill you no problem

 

[RichardM]

Loose wire.
Check the connector block to see which screw is loose.
If the bundle with the two reds, G/Y and three black go to the motor enclosure I would guess it's next to the other incoming red wire and is from the motor cover interlock which someone has made redundant.
Red on Boxfords used to be the control circuit colour, look at your transformer output / interlocks to check.

Looking at your photos I would say the suds pump which is supplied by the Brown, Blue and Black wires going to the switch, as said above check where these come from and the switch output. If these check out OK take the cover plate off the motor and check the connections there.

Before all that though does the switch rotate all the way round, or is it two or three position?, according to your second photo the knob/switch is upside down to the panel, has it turned in the panel or the forward/reverse switch and someone has swapped the switches.

 

[Matrixx]

The motor runs and will reverse

I found a loose wire but think I'll need a wiring diagram but doubt I will find one for this set up...
The earth isn't loose though

There were no safety cut offs I can see/ followed the wires around



ThanksView attachment 382036View attachment 382037

so its fixed now?

 

[CaptainPugwash]

so its fixed now?

Nope