Iwd7145 Door Switch Cable Core Identification

[fergus45]

Hi Guys,

I am having some difficulty with a Metalflex ZV 446 door switch on a Indesit IWD7145. I found the plug on the switch completely melted the other day and the washing machine had tripped the household electrics. I've got a new switch now & I don't know which terminals of the switch the wires are supposed to go to. There are three cables, two brown and one red, the switch terminals are 2,3 & 4. When I measure the voltages, I get 10V DC switching on one of the brown cores when I try to start the program and the other brown has 240V AC, the red seems to be neutral to earth. Any help greatly appreciated.

[Whitegoodshelp (Andy)]

To work out how a door interlock is wired up you need to understand how they work which is why I wrote this article how does a door interlock work?

[fergus45]

It's a really good article, and it makes perfect sense, I assume that you could effectively short out all three wires live neutral an common and the machine would think the door is locked? only thing with my machine is that I have a 10VDC supply switching when i start/stop the program on what i suspect is the neutral wire. I am starting to think there is a short on the neutral or the board. Is 10vdc enough to heat the bimetalic strip to expansion/bend point?

[Whitegoodshelp (Andy)]

If you shorted out all three wires it would blow up. Live and neutral must never be connected. The neutral is only there to allow the bimetal coil to work so if a door interlock was to be bypassed the neutral would just not be used.

I'm not aware of any door interlock that works on low-voltage. As far as I know they are all mains voltage though there would be nothing to stop the manufacturer making components to run on lower voltage if they wanted though I can't think of any advantage in doing so.