Contactor advice please

[fizzy]

Trying to get my powered knee on the xyz3000 to work.
Nothing happens when I turn the switch. Switch seems fine. Checked continuity and no problems.
Limit switches also fine.
Motor runs perfectly if I press down on the contactors.
Any ideas?
K31 controls up and K32 down.

 

[sparkysy]

Sounds like the contactor coil is at fault form what you describe, although worth also checking you have continuity to the negative of the coil wiring just in case!

 

[Robotstar5]

Are you getting power across A1 - A2 (coil connections) when you operate the key?, if yes, suspect coil, but as it happens on 2 contactors I would suspect a wiring problem on the control circuit.

 

[minimutly]

You can't fault find by continuity Vince, you need a meter on volts - check supply to the switch and out of it in both "directions".
If you have supply go to the A1 on the coils, if you have supply there, test A2. If you have supply there then you have indeed lost Ov. If you've lost Ov look for a broken or dislodged wire.
The machine has an e-stop system? That would prevent it running....

 

[fizzy]

You can't fault find by continuity Vince, you need a meter on volts - check supply to the switch and out of it in both "directions".
If you have supply go to the A1 on the coils, if you have supply there, test A2. If you have supply there then you have indeed lost Ov. If you've lost Ov look for a broken or dislodged wire.
The machine has an e-stop system? That would prevent it running....

I will over the weekend. E stop must be ok because everything else works.
Int40 certainly a lot beefier than a Bridgeport R8.

 

[DAPPH]

Fizzy do you have a decent multi meter ? If not I have one & should I find where I've left it will bring it in with me on Saturday .

 

[Hotstuff]

Is this a new piece of equipment to you that’s not working or has it just failed in operation?

The fact that neither the up or down contractors are working makes me think that it’s not the coils.

The problem with a basic continuity test is that they may indicate continuity but that continuity may not be sufficient to flow enough current to operate a coil.

Without a circuit diagram it’s tricky to diagnose but assuming the contractor coils are good, I would be looking upstream to the master contractor.

Are all the contractor overloads set just encase the volt free contacts are in use?

Are all three phase voltages present? Just encase the controls are 400 Volt but the motors are 230 Volt.

If the motors are 230 Volt, check if you have a neutral to the control panel.

 

[Matrixx]

meassure across A1 & A2 with a voltmeter when it should be on.

 

[prepman]

Total guess. but it sounds like a protection circuit fault e.g. limit switch. Coils usually get a bit stinky. But only way to determine it is to meter across coil with key operated.
Circuit diagram?

 

[arther dailey]

as above, power to coil or coil fault .

 

[fizzy]

Is this a new piece of equipment to you that’s not working or has it just failed in operation?

The fact that neither the up or down contractors are working makes me think that it’s not the coils.

The problem with a basic continuity test is that they may indicate continuity but that continuity may not be sufficient to flow enough current to operate a coil.

Without a circuit diagram it’s tricky to diagnose but assuming the contractor coils are good, I would be looking upstream to the master contractor.

Are all the contractor overloads set just encase the volt free contacts are in use?

Are all three phase voltages present? Just encase the controls are 400 Volt but the motors are 230 Volt.

If the motors are 230 Volt, check if you have a neutral to the control panel.

I just acquired it.
The belt was missing off the motor. Looks like it had been like that for a very very long time. DRO scales had to be removed to get at it.
Motor is 3 phase 400v.

 

[fizzy]

Fizzy do you have a decent multi meter ? If not I have one & should I find where I've left it will bring it in with me on Saturday .

I have several thanks.

 

[fizzy]

The limit switch on the winding handle works - contactors trip out if you leave the handle attached.
I will have to check the up/down limit switches next. When I opened the box up it was full of what looked like green sawdust
Blew it out with compressed air they actually look fine. Will test when I get a helper.

 

[fizzy]

Are you getting power across A1 - A2 (coil connections) when you operate the key?, if yes, suspect coil, but as it happens on 2 contactors I would suspect a wiring problem on the control circuit.

What are those fancy looking gadgets for attached to the right on some of the contactors?

 

[scottmk1]

What are those fancy looking gadgets for attached to the right on some of the contactors?

Overload trips

 

[daleyd]

These? They are overloads, will trip out if the current set on them is exceeded.

 

[Matrixx]

What are those fancy looking gadgets for attached to the right on some of the contactors?

Thermal overloads, the coil control circuit will pass through these.

 

[minimutly]

These? They are overloads, will trip out if the current set on them is exceeded.

View attachment 437836

Have you tried pressing the red t*t?