Earth Leakage?

[flukeyspark]

Hi all,

Hope you can help..? Here goes... I split a kitchen/garage ring final and added 2 sockets, all end to end tests are fine, IR test >299 on megger so thats fine..The board is an old MK Sentry with 80A 30mA RCD as main switch. The circuit is fine until the washer is pulled in, then it trips, I've tried the washer on another circuit and again it trips...So im thinking its the washer? The customer says the washer never tripped the RCD before? I've tried to test the RCD but as soon as I plug my meter in it trips, same when trying to get a Zs reading. I've taken the kitchen/garage circuit off the board completely and still can not get a RCD or Zs reading due to tripping..So now im thinking its a dodgy RCD?
The customer has today called me to say a washing machine engineer has been out to look at the washer and told him its not either the washer or the RCD! He has told the customer he thinks its a problem with the circuit? As i said earlier all test for the circuit were fine... Anyone out there got any ideas? I've spoken to the NICEIC and they think is due to combined earth leakage and advised to put a meter on and test but doesn't a ramp test do the same thing?
Any help on this would be really appreciated

Thanks in advance

 

[Knobhead]

Was it OK before you played about with it? Afterwards?

 

[flukeyspark]

Hi all,

Just wanted to let everyone that replied to my post that it is now solved! The problem was a faulty RCD. I got there this morning and ramped tested the RCD at the board with all the circuits switched off and got a reading of 15mA. I changed over the RCD, ramp test that and got 27mA
Got disconnection times of 28.8 x1 and 9.7 x5 and a Zs of 0.48. Obviously all appliances are staying on too, so customer can have washer and dishwasher running at the same time, all good!
Just a quick question - do you guys do a full installation test before you start any alterations? In hindsight this would probably spotted the problem before I started any work and I am now considering doing full testing before hand!
Thanks for your help on this subject everyone!

 

[Bonner]

This type of issues coming usually in the appliances so first switched off and also plugged off the appliances then do the RCD test it will show problem wherein appliances or earth leakage.

 

[Engineer54]

Hi all,

Just wanted to let everyone that replied to my post that it is now solved! The problem was a faulty RCD. I got there this morning and ramped tested the RCD at the board with all the circuits switched off and got a reading of 15mA. I changed over the RCD, ramp test that and got 27mA
Got disconnection times of 28.8 x1 and 9.7 x5 and a Zs of 0.48. Obviously all appliances are staying on too, so customer can have washer and dishwasher running at the same time, all good!
Just a quick question - do you guys do a full installation test before you start any alterations? In hindsight this would probably spotted the problem before I started any work and I am now considering doing full testing before hand!
Thanks for your help on this subject everyone!

So if everything was OK before you added these two extra sockets, then it was probably your IR testing that buggered the RCD then!!
By the way, the correct method of ''confirmation'' testing a RCD/RCBO is at the unit itself within the CU/DB, not downstream.