Washing machine Shock not switched on????-NOW FIXED WITH PIC

[chaban48699]

Hi,
Very strange situation today wondering if anyone could shed some light please. My CANDY washing machine was not draining well, took apart the top to access drain pipe inside machine.

Found blockage, removed, and started reassembly. Accidently touched live connection inside and OUCH shock on my finger, tested with Neon screwdriver (i know only thing I had to hand!!) and low and behold lit up!!!

Now heres the thing the machine WAS plugged in but switched OFF at double socket, switched it on at socket and the tester did NOT light but machine works perfect??!!

Stumped me, any ideas??!!!

 

[Steve]

Probably residual charge. Capacitors on circuit boards etc can hold a substantial jolt.

 

[chaban48699]

right ok, makes sense it was on standby for some hours before i took it apart. thanks

 

[HarryM1BYT]

Could be due to several problems, but it needs to be properly checked out...

1. A poor or no earth meant the casing was live.

2. The switch at the socket was faulty - live all the time.

3. L and N were swapped over at the back of the socket, meaning the N would have been turned off, but not the L.

When working on things - do not rely on the switch to make it safe, always pull the plug.

 

[chaban48699]

my initial thought was swapped wires in the socket I will check this now. update in a bit.

 

[chaban48699]

oh dear here is the prob-all now fixed and dunno what the red tape on neutrals are all about all now sorted.

Thanks View media item 20114

 

[mfarrow]

3. L and N were swapped over at the back of the socket, meaning the N would have been turned off, but not the L.

Sounds plausible to me, any live wire in the machine would be live when off at the socket, but isolated when not!

If no luck there, check elsewhere (other sockets etc). A friend's electrician's mate once wired a consumer unit up with the neutral and live tails mixed up, so the only thing protecting the installation was the cut-out.

 

[HarryM1BYT]

Well done

It might be worth your while checking the rest of the sockets, especially the ones directly adjacent to that one in the ring circuit.

 

[chaban48699]

thanks harry. I have been running the washing machine with this setup for over 3 yrs and it has worked perfectly would it not have any adverse effects on the machine???

 

[Steve]

thanks harry. I have been running the washing machine with this setup for over 3 yrs and it has worked perfectly would it not have any adverse effects on the machine???

No. Many houses have reversed polarity at the mains intake!

Whilst its not right, It doesnt harm appliances. AC appliances are inherently designed to run on either polarity. The direction of current changes 100 times a second, so it doesnt make an iota of difference. The only difference between live and neutral is that the neutral is tied down to earth. Only the live carries a dangerous potential, but it goes from +320v to -320v (or thereabouts) 100 times a second.

Just look at many foreign plugs and sockets - many aren't polarised. You can insert the plug either way and it'll work.

 

[HarryM1BYT]

thanks harry. I have been running the washing machine with this setup for over 3 yrs and it has worked perfectly would it not have any adverse effects on the machine???

The machine does not care which way round it is connected, it works fine either way, but you will. Neutral is at earth or ground potential and connected to ground either at your cut out or at the sub-station. In the UK the switches only switch off the Live, so if polarity is reversed, the Neutral will be switched - but still leave the live applied (as you recently found). It is the Live which bites.

 

[Monkeh]

In the UK the switches only switch off the Live, so if polarity is reversed, the Neutral will be switched

You can get these fantastic things called double-pole switches these days.

 

[Spark123]

One issue with the UK system and this is the plugtop fuse is always in the line conductor (what a lot of people call the live).
If there is an earth fault in the appliance then it will need to clear the fuse back at the consumer unit (30A?) as opposed to the 13A in the plugtop in your case.

 

[333rocky333]

Now heres the thing the machine WAS plugged in but switched OFF at double socket, switched it on at socket and the tester did NOT light but machine works perfect??!!

I assume the neon lit on the neutral.
Sounds more to me that your neon was picking up a voltage on the actual neutral.
If it was inadvertently connected to the live, it would also have been live with the socket on.


As for the blue/ brown crossed, I would check with a proper tester, they may have not been conversant with the new colours at the time and the Blue may have been used as Live, why else would they mark it Red
You may have now actually reversed polarity by changing it.

 

[ban-all-sheds]

PROBLEM: My CANDY washing machine...

SOLUTION: Miele, Bosch, Siemens...