new washing machine trips rcd

[ian1511]

washing machine trips rcd when turned on or off? this is on a newly installed ring on a recent job.as work had all been tested and no problems, job signed off and walked away. machine was 5-6years old recommended they get it looked at by an engineer, but they instead bought a new one.this still trips rcd when turned on or off.i have since been back and tried to pinpoint what is causing this but have hit a brick wall.it is only a washing machine that causes this have had dryer,extractor,undercabinet lights,2kw oil filled radiator,hoover,power tools,used on circuit and no problems.any one got any thoughts,thanks.

 

[oldtimer]

This might be a silly question but did you "PAT" test the washing machine the reason I ask is I had a problem like this when the customer switched the WM on via the FCU above the worktop I tested the WM and it was fine so before I started to scratch my head I tested the socket fed off the FCU and found the problem was that the screw had nicked the neutral behind the socket

 

[ian1511]

i pat tested there old machine and it did pass leakage was little high but pass.i have retested all my work and changed over face plates in case one was faulty, everything fine.customer can be hard work and didnt believe me so i by-passed all my work and ran a brand new extension lead and hard wired to mcb.this still trips rcd when turned on or off.have ramp tested rcd and also fine.

 

[scotsparky]

you tested all aplliances and totaled earth leakage? If WM is high it may bush rcd uper limits. also Ramp test rcd see whats its tripping at

 

[ian1511]

ramp test trips at 26mA, there is also a cooker cct and lighting cct fed from this rcd db and everything can be on including all other appliances, only when a wm is used this problem occurs.

 

[i=p/u]

which would incline to me its taking it over the limit... stick washing machine on rcbo or separate rcd or wire it in fp200 type cable... hopefuly jobs a gooden

 

[Edd]

I had this about 6 months ago sparks was called re RCD tripping, all tested out fine,,but would trip when W/M used they had brought a new W/M and it still tripped,, I was called and tested everthing. full load kettle, tumbledryer, shower all on together no trip! I/R all >200M ohm. I did a timmer test and at x1 the RCD was tripping at 7ms.. I thought this was quick but dismissed it as everything else worked and didnt cause tripping, I also thought W/M. But just as a last ditch effort swoped over the RCD.. new RCD time 36ms@ x1 and now no W/M tripping!! hope this helps....

 

[ian1511]

wm trips rcd when nothing else is connected to the cct, i' am going to replace rcd on friday to see if this helps even though all tests seem fine and then after that have no more ideas.even if i try and pull in new cct i think problem will remain as i tried this with extension like mentioned before.

 

[wildgoose]

Does the washing machine still trip the RCD when plugged into another socket ? Use an extension cord to try it elsewhere.

If there's another house ring, then does it trip the RCD in that circuit too?

 

[ian1511]

plugged wm into cooker point via extension and it tripped rcd, the cooker is a 5kw and been working fine at full whack since job was finished. rest of house isnt protected by rcd so they are currently running a lead from front room so they can use there wm.

 

[Richard]

To take a punt, I think changing your RCD could well clear the problem. I hate to say it, but it might just be one of those things!

 

[steve50]

has the wm got an inverter some of the new ones are now fitted with

 

[Marvo]

Sounds to me like you'll need to get down and dirty and localise the fault within the washing machine with your mega tester. I've had earth leakage faults that were caused by the noise supression filters on an appliance and they only showed a fault with a mega tester when using 250volts test voltage and not at 500 or 1000 volts. At 250 volts it read approx 1.5meg ohm but at 500v it read >15 meg ohms. I have a very old analogue tester that has a 200volt mega test and that showed a reading of 0.2 megaohms.

 

[Engineer54]

Sounds to me like you'll need to get down and dirty and localise the fault within the washing machine with your mega tester. I've had earth leakage faults that were caused by the noise supression filters on an appliance and they only showed a fault with a mega tester when using 250volts test voltage and not at 500 or 1000 volts. At 250 volts it read approx 1.5meg ohm but at 500v it read >15 meg ohms. I have a very old analogue tester that has a 200volt mega test and that showed a reading of 0.2 megaohms.

This is just one of the very good reasons, why most modern high end IR testers and MFT's have 100/250/500/1000 volt ranges... Sometimes less is better for realistic or accurate values!! lol!!!

 

[ian1511]

changed rcd today and it held,thank god.very unusal but at least its now sorted and i no if i ever cross this type of problem again.