Coolant pump

[FMESParticipant @fmes]

As the pump seems to be running at approximately 2/3 of rated speed could a phase winding in the pump motor have failed? I'm not an electrician but it seems a logical idea.

[Les Jones 1Participant @lesjones1]

Hi Rob,
Am I correct in assuming that you are just trying to run just the 0.1 Hp (About 80watt) motor from the 3.7 KW converter with no other load (ie a motor of more than 1.0 HP) ? If this is the case then the reactance of the capacitors will be so low they will produce hardly any phase shift with such a light load. From your voltage readings I am surprised the motor runs at all.

Les.

Edited By Les Jones 1 on 10/11/2013 20:27:42

[Sub MandrelParticipant @submandrel]

I think Les is probably right, and the voltage readings reflect this.

You may be able to run it by wiring the normal 240V mains across two of the phases and using a suitable capacitor (say 4uf-ish >240V rated) from one of those two phases to the third one.

I found some excellent advice on this HERE:

Neil

[Les Jones 1Participant @lesjones1]

Hi Neil,
Your idea may work but the motor would be running on only 240 volts instead of its rated voltage of about 400. A step up transformer would solve this problem. Another solution would be to dismantle the motor and find the star point and run it from 240 volts between the star point and and direct to one phase with the capacitor between this phase and one of the other phases. (The third phase not connected to anything.)

Les.

[RobonthemoorParticipant @robonthemoor]

Yes this is the problem, I did not see the . Before the 1 very sorry all for the confusion. Al kept on saying to me 1 hp sounds a bit big for a coolant pump, sometimes we just get our head in the sand. Thanks for all your input & gens.

Rob

final say, should be 0.1 hp

[jonathan heppelParticipant @jonathanheppel43280]

You'll definitely need a pilot motor. I'm still a little confused since I thought you're discussing a grinder- do you mean the grinder spindle has its own inverter? Anyway, try wiring a 1hp-2hp motor in parallel. Best way is wire it directly on the converter output so it's running already before you try the suds pump. Ps check the pilot's still star wired, and not delta for an inverter.

Edited By jonathan heppel on 11/11/2013 18:32:43

Edited By jonathan heppel on 11/11/2013 18:37:44

Edited By jonathan heppel on 11/11/2013 18:42:24

[John Stevenson 1Participant @johnstevenson1]

Posted by Robonthemoor on 09/11/2013 21:58:38:

Posted by Robonthemoor on 09/11/2013 21:48:00: this is the pump in action, as you can see fluid is pouring out the drive shaft turret below is the pump above is the motor, I have only put water in it so the inlet at the bottom of the pump is covered, the blades on the pump are good & a good gasket seal was found so no problem there. Do you recognise this type of pump, British made.

If coolant is coming out of the shaft turret then the seals are knackered, nothing should come out the shaft housing.

[RobonthemoorParticipant @robonthemoor]

No seals in there, if I get chance tomorrow night I will take a photo.

rob

[John Stevenson 1Participant @johnstevenson1]

Usually has a PTFE bush in there to support the shaft and act as a seal.

If it's missing it won't allow pressure to build up and throw the coolant out the connection.

[RobonthemoorParticipant @robonthemoor]

Rob, as Dave says above, the pump housing must be fully immersed in the fluid being pumped, most run with fluid covering the pump by a good couple of inches.

Most of these pumps (that I've seen) do pour out a fair bit of fluid from the shaft housing when running, this is to prevent cavitation (and the noise that ensues) when the pump outlet is stopped off and also helps to maintain a good mix of coolant fluid.

Edited By Lofty76 on 09/11/2013 22:43:41

[RobonthemoorParticipant @robonthemoor]

sorry to state the most obvious but is the rotation correct. Yes a gap in the housing to shaft is normal to allow the outlet on the discharge to be throttled and release the excess flow back to the tank.

Is the converter variable speed

Eric

[RobonthemoorParticipant @robonthemoor]

I've fitted a fair few bearing & seals in my time, and I'm almost sure no seal was in that housing, but I can imagine some do have seals, I must say I would expect to see one, but" as the text above says,, pressure has to escape when the tap is off, & not a relief valve in sight .

rob

[WALLACEParticipant @wallace]

It does look similar to the suds pump in my l5a. I persuaded that to run on 240 volts single phase with a capacitor that very conveniently fitted in its terminal box.

It did sound a bit sluggish so finding the star point as Les suggested would probably give it a bit more get up and go !

I gave up using it to be honest after a few weeks as the tools and other bits and pieces that seemed to accumulate in the drip tray would end up floating in a pool of suds …

So I currently use a cheapo trigger plant spray with the nozzle set to produce a solid jet of coolant.

W.

[FMESParticipant @fmes]

If coolant is coming out of the shaft turret then the seals are knackered, nothing should come out the shaft housing.

Not so John, as I said before, and wandering around the machine shop at work yesterday, all of the Colchesters and Harrison pumps that were in use were venting from the slot in the drive shaft housing.

One pump that was out for cleaning had no provision for any seal nor any bearing in the pump housing and had a fairly large clearance around the pump shaft.

Even at 2000 Rev/min Robs pump should be more than able to lift a meter or so with a good flow PROVIDED the pump housing is fully immersed, I think my single phase pump runs at about 1500?

And it vents up the shaft.

[WALLACEParticipant @wallace]

Lofty’s comment about immersion of the pump rings a bell (it’s a bit hazy as it was when I first bought it about in 1995).
I seem to remember firing it up and nothing coming out even though the motor was running. So I added another gallon or so of suds and away it went.

If I can, I’ll try and take a photo but may not be able to as a car without much in the way of running gear is fairly hard up against the lathe at the moment.

W.

[John Stevenson 1Participant @johnstevenson1]

OK I stand corrected.

I'm far more used to working on a higher class of pump than fitted to Colchesters and Harrisons

As my daily job is doing a lot of repair work for the motor rewinding companies I do get to see all different kinds of pumps. However I usually only get to see part and not whole units.

Some do have PTFE seal in as I keep it in flat and bar form just for these jobs.

[FMESParticipant @fmes]

Posted by John Stevenson on 12/11/2013 09:13:44:

OK I stand corrected.

I'm far more used to working on a higher class of pump than fitted to Colchesters and Harrisons

I would also affirm that the Colchester pump is more a 'stirrer with attitude' than a pump per se.

[RobonthemoorParticipant @robonthemoor]

All done and working as it should, once we established it was .3 hp not 3hp, Al204 gave me his small converter he no longer uses and bigo 2800rpm and pumps like a good-en.

thanks all for you help, could not have done it with out you.

Rob

[Les Jones 1Participant @lesjones1]

0.3 HP ???? Yet another figure. I thought it was decided it was 0.1 HP as marked on the plate. Accurate information to start with would have caused less confusion.

Les.

[RobonthemoorParticipant @robonthemoor]

This iPhone and big finger don't go well,

0.1 hp is correct,. Sorry

rob

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