Testing RCD on shower circuit

[voltage]

This is a picture i've taken of my megger and test leads connected to do the RCD test on my mk dual RCD board

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Obviously i have not put the busbar in yet but u get the drift.

Main switch on MCBs off RCD ON then test load side of RCD line to earth for that particular RCD or like not so clever pointed out if the RCD side you are testing has a circuit using socket outlets then just use the plug on the megger and test at socket outlet.
first test 1/2 then 1 then 180 wave then 5 then 180 wave record two highest results. The 1/2 test should not trip this is a test to gauge how sensitive the RCD might be ?
Then finally test the manual button on the RCD to see if it works.

 

[IQ Electrical]

Looks fine, you do your tests right there on that RCD and the results will apply to the 4 circuits protected by that RCD.

 

[voltage]

yeah thanks then ill repeat the same test for the second RCD and that will take into account the 3 circuits on that RCD.
Thanks for fast reply volt.

 

[telectrix]

personally, i just plug in to the nearest socket outlet, with loads removed. problem with using probes is breaking a connection when resetting the RCD. it's rare to find a RCD without at least 1 socket circuit on it. ( RCBOs excepted )

 

[richy3333]

And finally... complete your ramp test

 

[Amp David]

It's a 2-lead test on the 1553.

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Thank god for that. Just read the post saying use 3 leads a started thinking i've been doing it wrong using the Megger.

 

[jamminuk]

Hi,

Sorry to jump in on this one but, something i come accross the other day, old style re-wirable fuse board with a completely separate rcd for the shower, the pull cord switch went in the bathroom so i just replaced it like for like, the rcd was operating mechanically but how would i test it at the shower/pull switch? (I've disconnected it for the time being). Can i just connect the leads at the pull switch? just seems a bit unsafe doing it this way as obviously it's a live test?

Thanks

Ben

 

[malcolmsanford]

You can do it there or at the the RCD itself. Better at the RCD itself as you won't have to test on a switch which is over head.

 

[telectrix]

test at the CU. it's easier. switch off all MCBs on the RCD you are testing. clip to earth bar, probe to L on load side of RCD. ( mft set to RCDauto ). switch on RCD, press test button on MFT. reset RCD each time it trips. read off and record trip times. enter the higher of each on schedule of test results. press test button on RCD to confirm operation. ramp test if required. done.

 

[jamminuk]

Still not sure as it's on re-wireable fuse board, shower circuit doesn't even go through the main fuse board, it's located separately mounted below. I thought rcd was live test?