Replacement transformer

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pavelmac

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#290195 26-Oct-2021 20:41

Hi All,

I have a range hood that has stoped working. Following the manufacturers trouble shooting I believe the issue is the transformer, voltage measured on input but nothing on output.

My issue is sourcing the the oem replacement. The transformer is a 120v to 12v 105w unit. This unit is only available in the US and none of the websites will ship internationally. I believe transformer is just for lights and controll panel.

So i can find "led" transformers, with at least that spec. Can i use one of these? Should i go for higher watts to allow for "Chinese labelling issues"?

Cheers

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#2801633 26-Oct-2021 21:12

Maybe you should add some more detail. Is this in use in NZ? Is it really a 120v unit?

SomeoneSomewhere

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#2801635 26-Oct-2021 21:19

Can we have some more information and pictures? It is highly unlikely that you need a 120V input transformer in NZ.

pavelmac

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#2801649 26-Oct-2021 21:55

Ok.

Range hood is a ge monogram zv750. The transformer appears to be part# wb17x10002.

I believe I measured 117v on the input side.

https://cdn.geekzone.co.nz/imagessubs/65110ef4b91bc874979f948eafb807c8.jpg

andrewNZ

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#2801666 26-Oct-2021 22:43

That must be doing something funky like running it in series with another item.

Is there more than one transformer. Is the fan rated 120v maybe.

pavelmac

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#2801676 26-Oct-2021 23:32

Just checked and the unit is plugged into the wall but then disappears behind the gib before re-emerging. I would guess that PO had a step down transformer installed there.

But I suppose what I what to know is are all transformers interachangeable, if the specs fit?

Here's the schematic:

gregmcc

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#2801682 27-Oct-2021 06:00

How do you know for sure that the transformer is faulty, did you disconnect the output load and check?

There are several transformer companies that will make/rewind/repair transformers.

You may be able to find one that is electrically correct but the mounting points and physical size may mean it wont fit.

pavelmac

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#2801717 27-Oct-2021 08:29

I simply used my multi-metet across the input & output terminals of the transformer, without removing the load wires. Is this a valid test of the transformer? My skills are limited to research, crude tests and replacing like with like
Any tips a to how to test the transformer?

I am worried that size will be an issue, so I'll look up those transformer companies

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pavelmac

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#2801784 27-Oct-2021 09:13

Doh.

I made the assumption that when the transformer dropped the voltage to 12V and converted to DC (subconscious connection with 12V with car batteries). But from double checking the schematic and testing with MM set to AC, it shows the transformer does convert the 118V to 12V as per spec.

So back to the trouble shooting.

Thanks.

Pav

Nate001

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#2801791 27-Oct-2021 09:40

I'm a bit confused how you're getting 118V input... Is there a hidden step down transformer somewhere going 240-120V?

hsvhel

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#2801794 27-Oct-2021 09:44

What part is not working, whole thing? or just motor/lights

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pavelmac

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#2801797 27-Oct-2021 09:51

- I think there is a stepdown transformer in the wall.

- It was whole thing not working, no lights, no control panel, no motor.

But I hope I've just solved it. I've found a blown fuse! I don't have a spare, but it should be hard to find a replacement.

Fingers crossed that will solve my issue.

DonH

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#2801800 27-Oct-2021 09:56

It's almost certainly a US market range hood. Clues are the 120 volt markings and the colours of the mains input wires. There will almost certainly be a stepdown transformer in the wall.

If you're set on replacing the transformer, look at 240 volt to 24 volt transformers.

Edit: Hopefully the fuse has just died of old age.

People hear what they see. - Doris Day

Nate001

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#2801809 27-Oct-2021 10:20

DonH:

If you're set on replacing the transformer, look at 240 volt to 24 volt transformers.

That will only fix the PCB/Control of the unit. The schematic shows the motor does not use the transformer so won't be happy with 240V 50Hz vs 120V 60Hz.

For simplicity I would replace with a 240V rangehood if possible, seems troublesome having extra complexity.

Maybe the fuse has blown because of old age, or there could some other fault?

pavelmac

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#2801819 27-Oct-2021 10:42

Will try the fuse and hope that it's just old age.

I guess previous owner had an eye for a bargain or something as he's made number of odd decisions in his renovation choices.

Anyway, if fuse doesn't fix it I'll probably looking for a simpler solution going forward i.e. 240V

Thanks for help & comments.

DonH

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#2801827 27-Oct-2021 10:52

Nate001:

DonH:

If you're set on replacing the transformer, look at 240 volt to 24 volt transformers.

That will only fix the PCB/Control of the unit. The schematic shows the motor does not use the transformer so won't be happy with 240V 50Hz vs 120V 60Hz.

...

True, but not relevant in this case.

People hear what they see. - Doris Day

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