Electronic advice

[kevin largeParticipant @kevinlarge76611]

I need a ceramic disc capacitor for a vfd the part no.
JD472MY1
I can only find them in China
My question is does anybody know if I could get one in the UK
Or recommend an equivalent

[kevin largeParticipant @kevinlarge76611]

[Anonymous]

Should be no problem getting one in the UK. I wouldn't worry about sourcing the exact code. The 472 is the easy bit, 4700pF. The M is a tolerance, should be +/-20%. Voltage is more of an issue. A picture and an idea of where it is in the circuit will help. It will also help to know the physical size of the component.

Andrew

[John HaineParticipant @johnhaine32865]

4700 pF 250v ceramic disk. Try RS components, farnell, mouser etc.

It may be a film type rather than ceramic.

[John RuddParticipant @johnrudd16576]

question addressed..

Edited By John Rudd on 31/01/2019 20:36:21

[Michael GilliganParticipant @michaelgilligan61133]

Spec. : **LINK**

http://www.jecco.cn/en/product.php?sid=54

MichaelG.

[Anonymous]

Posted by Michael Gilligan on 31/01/2019 20:35:03:

Spec. : **LINK**

http://www.jecco.cn/en/product.php?sid=54

That's useful, it'll be easy peasy to get one in the UK. Any competent supplier will stock them. Just make sure it's rated to Y1 duty. Like this:

**LINK**

Andrew

[kevin largeParticipant @kevinlarge76611]

Thanks guys I’ve managed to upload some pics into my album hope they help

[The Novice EngineerParticipant @thenoviceengineer]

Try this

**LINK**

for more choice

**LINK**

[HughEParticipant @hughe]

Kevin,

Rapid electronics part 08-1560 £0.156 each MOQ 5

Hugh

[kevin largeParticipant @kevinlarge76611]

Thanks guys I’ve now ordered
But have now found more problems pics in album

[SillyOldDufferModerator @sillyoldduffer]

Which model Warco lathe is it Kevin?

I agree with Martin C (in the VFD / capacitor thread) that the white stuff on this photo is normal heat transfer paste.  I don't see anything suggesting a short to the heat-sink, fingers crossed:

Next is more sinister, the white marks on the terminal strip and black marks on the board bottom right near the blue mains filter capacitors look like heat damage. Can't read the label on the damaged end of the terminal, but I guess it's earth. What was the lathe doing when the electrics failed?

Can you take a few more focussed photos of the affected area from various angles, and of the other side of the board. With luck the fault is only that the capacitor shorted to earth and burned the track underneath away and that can be fixed by soldering a wire bridge across the gap. But that theory doesn't fit too well with the badly fried switch – whatever did that may have done a lot of damage to the VFD.

Do you have a circuit diagram?

If it's necessary to replace the VFD at least they're not as expensive as they used to be!

Dave

Edited By SillyOldDuffer on 02/02/2019 19:33:55

[kevin largeParticipant @kevinlarge76611]

Thanks Dave
The end terminal is earth
When it went I plugged it in the vfd came on then flicked the switch to start lathe and it flashed and that was it
It worked fine day before but was cold in garage and I think the speed was set quite high so don’t know if that’s what caused it

[kevin largeParticipant @kevinlarge76611]

Hi Dave I don’t have a circuit diagram
And in the first pic did you see the little bit burnt out on the thing with the white stuff on no 9 in from the left

[kevin largeParticipant @kevinlarge76611]

Have added some more pictures

[John HaineParticipant @johnhaine32865]

If lathe is cold oil is more viscous and motor has to work harder. My lathe certainly takes longer to run up to speed in this weather. On the other hand, if this is a real VFD (i.e. the motor is a 3 phase induction motor) it should have been designed and configured not to blow up on overload.

Was this original equipment on the lathe, and was it still under warranty? If it was you have clearly invalidated the warranty! IMHO the best advice, if this was original equipment and the motor is a VFD, is to junk it and buy a decent one properly rated for the motor; and with assistance from the forum configure it properly to shut down on overcurrent / stalling.

[SillyOldDufferModerator @sillyoldduffer]

Kevin pointing out the damage and his new photos aren't encouraging.

On first contact I thought all the damage was concentrated near the earth terminal and nearby mains filter capacitors. Not so!

I'm not familiar with the component I've guessed to be a single combined 'Rectifier and Controller Chip?'. But it appears to be heat damaged in the area circled in red. Also other heat damage, including what might be a bubbled track, in the areas circled in yellow. I think this is 'Beyond Economic Repair', ie cheaper to buy a new VFD than to diagnose and repair, even if you can get the parts.

The combined 'Rectifier and Controller Chip' shorting to earth via the heatsink would explain the damage to the board, but I don't understand what happened to the rotary switch, or how a short on the switch might have done the VFD in.

Might the root cause be the motor, perhaps a shorted winding pulling enough power to fry the rectifier and the switch? John's comment about the need to set the over-current protection correctly might explain all – possibly the VFD was been running in 'Damn the Torpedos' mode, which works very well until something goes wrong! What should Kevin do to confirm the motor is OK?

Dave

Edited By SillyOldDuffer on 03/02/2019 13:18:13

[not done it yetParticipant @notdoneityet]

‘Flicked the switch to start the lathe” may have some bearing on the failure. It is usually “pressing of a contact button” which ramps up the motor power/frequency.

If the OP has switched the three phase supply to the motor, that may well be sufficient to blow the VFD. Most smaller VFDs warn against switching on the three phase side.

So, is this the case?

Edited By not done it yet on 03/02/2019 13:36:44

[kevin largeParticipant @kevinlarge76611]

I turned on the power to vfd then flicked the start switch on the vfd via a remote pod

[kevin largeParticipant @kevinlarge76611]

Oh forgot to say lathe is running fine on another vfd

[SillyOldDufferModerator @sillyoldduffer]

Posted by kevin large on 03/02/2019 14:26:01:
Oh forgot to say lathe is running fine on another vfd

Best news so far – it means the motor is OK!

If it were mine I'd replace the VFD and move on.

Although I have the means to fix electronics I lack the patience to do it well and I don't enjoy working on SMD &/or multilayer boards. Also, because a few spare parts can easily cost more than a whole new unit, I feel repair isn't time well spent unless it's quick and easy. Others have enormous fun mending broken circuits, not me!

Cheers,

Dave

[John HaineParticipant @johnhaine32865]

Anyway, the fact that this one blew up suggests it isn't worth repairing anyway.

[Anonymous]

Posted by John Haine on 03/02/2019 16:38:05:

Anyway, the fact that this one blew up suggests it isn't worth repairing anyway.

+1

Bin it and buy a decent VFD.

Andrew

[kevin largeParticipant @kevinlarge76611]

Ok many thanks to all and especially Dave looks like I will have to go shopping again

[Author]

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