Power transformer equivalent

[Theblackbox]

Hi all got a promecam Pressbrake with Hurco autobend 7 cnc control unit. Keeps powering off completely eventually I can get it to switch on again only for it to switch off again

I’ve spoken with an engineer that I know and they suggested the control transformer is probably faulty.

I’ve opened the cabinet and sure enough it’s red hot to touch so that’s potentially the cause so was going to swap for a new one and hope that solves it if not I’ll have to call an engineer in to look at it

Just wondered if anyone can suggest a direct replacement for it I’d prefer a good quality unit as this is used quite a lot.

Thanks everyone for their help.

 

[daleyd]

Can you see what current it’s pulling on the secondary side, use a clamp meter if you have one suitable? I would determine whether the transformer is actually faulty before you start thinking of replacing. It could be something on the secondary side that’s gone faulty and is pulling too much current or even if something has been added at a later date and not been considered.

 

[Matrixx]

I would think at 43VAC its going to be difficult to find an off the shelf one.

Could try these guys we used to get custom TX's made for us all sizes.

Carroll & Meynell Transformers Ltd
Guiseley Way
Durham Lane Industrial Park
Eaglescliffe
Stockton-on-Tees
GB-TS16 0RF

Tel: +44 (0)1642 617406
Fax: +44 (0)1642 614178

 

[MoreWellie]

It is the 300va that will make it difficult as there are a number of 22v-0-22v transformers around which will give 44v across the outside which is probably acceptable but I would agree with @daleyd and check the load first

Edit: they are available a quick search gave https://www.toroidal-transformer.co...0va/95/2x-22v-toroidal-transformer-300va.html

 

[Theblackbox]

Thanks everyone I don’t have a clamp meter but I’ll pick one up as it will come in handy.

I let it cool down gave some of the wiring a jiggle and it’s stayed on for quite some time and hasn’t switched off so will see how it works out tomorrow could be that it’s got a bit too hot or poor connection.

 

[Martin-Sy]

Lots of good advice given so far and yes, check the output current with a clamp ammeter.
300VA at 43V would correspond to a secondary current of about 7A.
There should be some margin in the design so it should be less than that.

Silly question - It's got a tapped primary for 120 or 240 volt operation so somewhere there will be a means of setting this - Is it set for 240 ????

If you can do it, disconnect the load and see if it still gets hot.
That would point to a 'shorted turn' where one of the windings has become shorted to the same winding one or more turns later.
The effect is that the output voltage will change a little, but the shorted windings get very hot due to current circulating within them.
If that's the case it's a new transformer.

Good luck.

 

[awemawson]

These people custom wound me a very high quality transformer when I was adding a CNC 4th axis to my Beaver Mill:

JMS infoTEC Ltd

Tel: 01733 760000

Fax: 01733 760004

20 Ivatt Way,

Westwood Business Park,

Peterborough,

PE3 7PG.

 

[Theblackbox]

Thanks everyone for their input given me a couple of things to check and test. I’ve had this machine for a couple of years and it’s been fine until recently so will be set correctly for 240 and also nothing has been added

I’ll pick up a clamp meter tomorrow will this be suitable

Kewtech AC Digital Clamp Meter 400A

Order online at Screwfix.com. Measures AC current to 400A and AC voltage up to 600V, plus resistance to 40KΩ. Click on the PDF instruction manual below for full specification. FREE next day delivery available, free collection in 5 minutes.

www.screwfix.com

Refreshing to know there are still companies in uk able to make transformers.

 

[Anguz]

Think you can still buy wind your own from rs?

 

[Theblackbox]

Picked up a clamp meter this morning it’s drawing about 3a on the secondary side that’s with no motors running but I need a second person to check the amps with it running but I think they have their own supply but not fully sure!

Looks like it switched off overnight as I came into it fully on (was left on standby) with the jobs list showing and both axis wanting to calibrate. So looks like I need to disconnect the load and see if it’s still getting hot as suggested by @Martin-Sy

Thanks all for your help much appreciated