Capacitors for HIGGS motor.

[Guineafowl]

I can’t see it starting up with one winding, as there would be no phase shift/torque.

I wonder if there’s a dicky thermal switch in there?

 

[Brad93]

I said it couldn't be a cap start, cap run motor when i saw the caps were wired together and you stated the caps were the same value.

 

[HSGB]

I said it couldn't be a cap start, cap run motor when i saw the caps were wired together and you stated the caps were the same value.

Well, I am knackered now and can hardly keep my eyes open. I do not know how the condensers are meant to be wired up. All I know is, is that it has run fine for me for about thirty years, ever since I was kid and dragged it out of the brambles, on a farm. What are the condensers for then? Yes there art two and they both have the exact same specifications, as the photo I posted. It was running fine before I changed the bearings.

I thought, once I managed to get inside, that it was in very good condition internally. I have now changed the bearings, after trying for the third time and have put it back as I found it. It rotates very smooth and starts without any odd noises, it just won't carry on running. I have this tiny half of a rivet but cannot find the other half or, where it came from in the first place. I knew nothing about this motor but after taking it apart, it is very basic in there so, this stupid piece of rivet hasn't got that many places it could come from. All I know is, is that I cannot find out where. Is it why it won't run now? I have studied the switch and that's pretty basic as well so, what can go wrong with it? I cannot see any damage to the switch and it seemd to operate smoothly. I was really careful with everything.

No, I can see no thermal switch. All I can see is the huge stator windings, the main shaft with the rotor on it, the centrifugal switch, the junction box and the two condensers.

I will have some more investigations tommorrow. and see what I can find.

 

[HSGB]

If I understand what's happening you switch on, the motor runs a bit, then stops.
1) does it reach full speed or thereabouts?
2) how long does it run for?
3) after it slows down and stops is it humming or buzzing?
4) do you have to wait for a while before it will repeat this cycle?
5) was there any sign of a thermal switch or cutout?

I'll take a look tomorrow.

 

[eddie49]

The run winding should be permanently connected. The capacitor on the start winding gives a current lead through the winding to start its rotation correctly, then is disconnected.

As Seadog said, there should always be continuity between the Live and Neutral pins of the mains plug, across the Run winding. Can you check this, using the Ohms range of a test meter?

 

[HSGB]

As Seadog said, there should always be continuity between the Live and Neutral pins of the mains plug, across the Run winding. Can you check this, using the Ohms range of a test meter?

Yes, I can check that. I wired it up years ago with a 16 amp plug.

 

[500e]

 

[HSGB]

That video is what I was reading about a couple of nights ago. How the switch acts to divert power to the run winding at a certain speed. But, it has been said, on this very thread, that that's not correct, what is it to be, then?

I checked continuity at these points. Once at the junction box terminals and, to check the actual cable, at the plug. Both had continuity and seemed fine. Whether it means anything to anyone, the continuity held even if I manually opened the switch.

Here is a clearer photo of the junction box wiring. I never altered any of this. All I have done is removed the two condensers but, I marked their connections and reconnected them exactly as I first found them but, with a couple of new, round post crimps.

I do not know what those those other thicker wires, at the bottom connect to, but they must be permanently live. Is it the feed for the main run windings and that's why they are so thick?

Do I remove the switch again and see if I can find the source of the rivet? I know I will find nothing though as I have already scrutinised it.

It has to be the switch not working right but, I cannot see anything wrong with it.

 

[Brad93]

Can you tell us the resistance of the two windings?

 

[eddie49]

Yes, I can check that. I wired it up years ago with a 16 amp plug.

The blue 16A connector in your photo is not a plug, it is a socket. If it is connected to the motor, this implies that you supply it from a loose plug with live 230v mains on the exposed pins?

 

[HSGB]

Yes, but it is on a DP isolator, on the wall. But yes, I see what you mean. If the isolator is left on the pins are live with no cover. I shall swap them around so that the socket is coming from the isolator and the plug is on the trailing lead on the motor. Good spot! It's been like that for thirty years!

Can you tell us the resistance of the two windings?

If you tell me from which terminals to go across,I will get the resistance. I have just noticed that there are three black wires at the bottom of the junction box. Actually four, I think! But only going to two terminals.

 

[Guineafowl]

Your run winding (4 black wires, bottom) is split in two for the dual voltage. In parallel here for the 240V. Maybe one of those is open circuit?

I guess red 5 goes to green 3 via the centrifugal switch.

Red wires marked Z1 Z2 are start winding.

You’ll have to separate the wires and measure to confirm.

 

[Seadog]

Brook Crompton, but might be of help.

 

[eddie49]

The continuity test that you did indicates that the Run winding is intact and correctly wired across the mains input.
As @Martin-Sy asked in question 3 of Post #58, when the motor comes to a halt after the initial run-up, does it hum or buzz?
It should, because the Run winding is there across the mains, even if it cannot self-start correctly.

Before the capacitor-start/centrifugal-switch idea, induction motors only had a Run winding, and they had to be started manually by "pulling on the belt". If you temporarily removed the metal bridge linking terminals 4 and 1 at the left side of the junction box that would disconnect the capacitors, the Start winding, and the centrifugal switch, leaving only the Run winding across the AC mains.
[Actually, Run windings, because there are two in parallel when this motor is configured for low voltage operation.]

If you plug in and power up after removing that link and tightening down the existing wires, the motor should not spin, but just sit there buzzing. You could try to spin it manually, with a gloved hand, in either direction. Alternatively, switch off, spin it up manually, and apply mains power whilst it is still rotating. It should keep turning and run up to full speed. If it does, there is something weird happening in the start circuit. If it does not, the run winding is failing.

 

[HSGB]

Right, I have these, after disconnecting them.

Between Z1-Z2: 3.9 Ohms

Between A3-A4: 1.6 Ohms. Black wires at bottom

Between A1-A2: 1.6 Ohms. Black wires at bottom

Between the green and red: 0 ohms. If I manually open the switch the meter goes 'OL' out of range.


I don't see why the windings should suddenly fail, I reckon it's something to do with this tiny, half piece of rivet. Do I reassemble it and try it again to get a better account of what's happening during power up or, do I have the switch off again?

 

[HSGB]

The continuity test that you did indicates that the Run winding is intact and correctly wired across the mains input.
As @Martin-Sy asked in question 3 of Post #58, when the motor comes to a halt after the initial run-up, does it hum or buzz?
It should, because the Run winding is there across the mains, even if it cannot self-start correctly.

I would have to put it back together to check better. When I fired it up last time because I knerw something wasn't right I turned the power off, sharpish. Is it alright to leave it sat there humming?

 

[eddie49]

No, without rotation it will overheat. Just do a quick On/hum-or-no-hum/then Off again.

..... It should keep turning and run up to full speed. If it does, there is something weird happening in the start circuit. If it does not, the run winding is failing.

For example, maybe the start and end of one of the two parallel Run windings has been reversed in relation to the other......

 

[HSGB]

For example, maybe the start and end of one of the two parallel Run windings has been reversed in relation to the other......

Why though, as none of it has been touched or meddled with? All I did was pulled the bearings off and drifted two new Koyos on. Everything went very smoothly other than this tiny, half rivet falling from somewhere.

 

[Guineafowl]

Right, I have these, after disconnecting them.

Between Z1-Z2: 3.9 Ohms

Between A3-A4: 1.6 Ohms. Black wires at bottom

Between A1-A2: 1.6 Ohms. Black wires at bottom

Between the green and red: 0 ohms. If I manually open the switch the meter goes 'OL' out of range.


I don't see why the windings should suddenly fail, I reckon it's something to do with this tiny, half piece of rivet. Do I reassemble it and try it again to get a better account of what's happening during power up or, do I have the switch off again?

Check for any continuity to earth, while you’re in there.

 

[eddie49]

If the half-rivet is related to the problem, it would only be in relation to the centrifugal switch, and thus the Start circuit.
The test that I suggested in Post #74 eliminates all that.

Thank you for the resistance values. They look reasonable.