RCD Test

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Mr_syrup

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Greetings to you all.

I am about to take my 2391 practical, tomorrow actually and Ive hit a brick wall..

Im pretty okay with everything (he says) except the RCD test.

Am I correct in thinking that the test is made across the phase on the RCD to CPC?

I have 3 leads, do I utilise the neutral or connect in to the CPC lead as in continuity testing?

My tester has an auto test function which tests at 50% 100% and 500% so almost everything is done for me.

Any help would be much appreciated.

I'll even buy the doughnuts!!

 

Flying Scotsman

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you have to put the earth clip to cpc

live probe on the live conductor

neutral probe on neutral conductor

hope that helps.

obvously that is at the other side of the rcd ie the actual circuit being tested ie end of the lighting circuit or equiv

 

Mr_syrup

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Lovely job. Thanks for that.

I thought that was the case but having tried it out on my installation at home it wasnt doing what it ought to have done.

Amazing what you find at home.

Like what you believe to be a ring main has no phase or neutral continuity and is actually 2 radial circuits from the same MCB. Quality!

Thanks again

 

M107

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All the best with the 2391

I'm sure you do the rcd test at a socket outlet on the 2391 course, use the plug lead if so.

 
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All the best with the 2391I'm sure you do the rcd test at a socket outlet on the 2391 course, use the plug lead if so.
But with Rcbo's being utilised a lot more you have to know how to test with leads. Don't make the mistake i do often and put the leads on the feed side of the Rcd, then wonder why it hasn't tripped :8}

 
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you have to put the earth clip to cpclive probe on the live conductor

neutral probe on neutral conductor
You sure ??? On my megger I only connect to neutral when trying not to trip RCD ie doing Zs on RCD protected circuits. All I use is clip to cpc and probe to phase/live/line whatever the nasty electric supply bit is called these days:D. The idea is to provide an imblance (ie leakage to earth) to trip RCD.

Good luck with the test.

 
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You sure ??? On my megger I only connect to neutral when trying not to trip RCD ie doing Zs on RCD protected circuits. All I use is clip to cpc and probe to phase/live/line whatever the nasty electric supply bit is called these days:D. The idea is to provide an imblance (ie leakage to earth) to trip RCD.Good luck with the test.
The new megger can do Zs on RCD cct without a neutral connection. However; I understand that we`re talking RCD testing, not EFL.

GN3; and the various courses and other info I have, all want all three conections to be on the meter.

Plus, the fluke has "idiot lights", which tell you which connections to make for each test. The fluke won`t perform the test without a neutral connection.

 

steptoe

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I would personally connect all 3 leads if your meter has them,

just check your on the load side,

sounds obvious but sometimes its the simple things you can miss.

also remember to press the T button after testing your trip times,

ALWAYS push the button last, NOT first. its your 5th test.

oh,

and GOOD LUCK,, :)

 

Mr_syrup

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Loads to go on, it seems that with my tester all i need to do is 'Auto RCD' plug the lead into a socket, 'start' and away it goes.

Any major fault such as failing to trip on 100% then the device will stop immediately and await my expert diagnosis. Ahem!

Thanks for all your help. Whos for doughnuts?

 
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The new megger can do Zs on RCD cct without a neutral connection. However; I understand that we`re talking RCD testing, not EFL.
My megger is far from new, the new beast can do Zs without a neutral on an RCD protected circuit and has auto RCD test, but for testing the RCD itself only uses two leads. Can't rememer what GN3 says. Generally speaking I use the test plug, but the obvious answer to the problem is read the manual that came with your test gear because they're not all the same - I'm just off to double check mine? :| .

 
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