Electric tumble dryer bipolar switch question

[Tim Downie]

My mother's Candy tumble dryer broke down the other day. That is, the power switch doesn't "latch" and as soon as you release the button, the drum stops.

I assumed that it was the power switch that had broken and ordered one of these.

I didn't read the product discription properly as I was expecting a latching switch. This seems to be a simple "push to make contact" switch so I'm a bit puzzled by the description of "bipolar". I assumed that it would have stable "on" and "off" position.

I haven't had a chance to have a closer look at my mother's dryer so I can't be sure where the fault is and I suspect that the switch may never have been the mechanically latching variety.

Can anyone confirm how this switch should work, where the "latching" occurs (electronic or mechanical) and what "bipolar" means in this context? I'm a bit puzzled.

Tim

[Andy Cap]

Don't know personally, but whilst you wait for a possible answer here, why not go to the bottom of the page and ask a question of the espares staff?

HTH

[Dave Liquorice]

Or click the link on the page that says what Candy driers the switch fits, assuming that your browser understands the javascript otherwise it's a broken page. Reading the description it seems pretty obvious that there are significant variations in this switch...

[Tim Downie]

It is, according to the model number, the right switch. More than anything, I'm just puzzled by it's description as "bipolar". I haven't made enquiries through the website as I haven't had a chance to strip down the dryer yet (it's 40 miles and one week away from being accessible). It may be all become obvious when I look inside. Until then, I'm just curious.

Certainly the new one isn't alternately giggling and sobbing so I'm not sure in what sense its bipolar. ;-)

Tim

[Baz]

> Well, I didn't read the product discription properly as I was expecting a

You need something with a Relay.

I found this

from the reviews.

Our Hoover tumble dryer was on the blink - the push in button would not start the machine unless it was held in and then there was a buzzing sound. Dismantled it and guessed that the relay board was malfunctioning. Thought it was worth a gamble so purchased this replacement. Result! Well over two hundred pounds saved on having otherwise to buy a new dryer. Easy enough to fit the PCB, but a bit of dismantling is required, hence three stars for ease of fitting.

Baz

[Tim Downie]

>>> Well, I didn't read the product discription properly as I was

That may well be right but it doesn't answer my question.

Tim

[Dave Plowman (News)]

Well, I didn't read the product discription properly as I was expecting

Surely bipolar is just a bad translation meaning double pole - as all these sort of switches are.

It wouldn't surprise me to find an on/off switch which wasn't a self contained latching type - it might be expected to trip because of an overload or whatever.

[Andy Cap]

Only the picture suggests it isn't double pole! I *think* it's to do with a bipolar transistor, which *could* be providing some kind of locking function but I don't *know*.

Andy C

[Tim Downie]

I'm pretty certain that it's a simple single pole, push to make contact type switch.

I realise that I've probably boobed ordering this switch as now that I know it's a PTMC type, it's almost certain that the problem lies elsewhere. I'm just a bit peeved because I would have realised this earlier if the switch had been more acurately descibed.

Tim

[Andy Wade]

Yep, mechanical interlock with door and/or airflow sensor to stop the machine if the door's open or the fluff filter's blocked (IME, YMMV).

[Tim Downie]

>>> Well, I didn't read the product discription properly as I was

This was indeed the solution. I realised early on I had been a bit hasty in my diagnosis as once I found out that this switch was a simple push to make contact, it was obvious that the fault *couldn't* lie with the switch as the drum would turn as long as the switch was held down.

espares were fine about refunding my money for the switch (and providing free return postage) so other than the product description, I can't complain about their service. (I did let them know about my reservations about their description of the switch so maybe they'll change it - though I won't be holding my breath. )

Tim