Home Test Records for MFT - Confused!

chrisgc · Jul 10, 2010

Hi

I am in the process of keeping test records for my megger1553 and have a checkbox which does the continuity and insulation tests BUT when it comes to doing the LOOP and RCD tests do I do the following (as some of the answers in previous post have confuddled me a bit):-

1) Choose 1 socket at home to do the loop and rcd tests. BUT does it have to be a dedicated socket or do you choose one socket which is currently on your normal household socket circuit?

2) For the loop and rcd tests does that socket you decide to always use, does it have to be RCD protected? (as someone informed me I should choose a dedicated socket but as long as its NOT rcd protected - which confused me)?

Yor answers would be most appreciated to clarify this point.

Chris

Sparky Ninja · Jul 10, 2010

Off the top of my head I believe you carry out the zs test at chosen socket, the applying the checkbox will allow the option to introduce a set increased resistance, from which your tester should then retest the socket and include exactly that amount of resistance..

Eg, you measure your zs as 0.47, then on the self checker it will introduce 1ohm, so you retest and it should be close to 1.47. Any deviation will make you aware of any irregularity.

Regarding the RCD testing, if you don't use a socket that's not on an RCD then it is likely that the circuit RCD will trip when carrying out the self check.

JUD · Jul 10, 2010

Hi Chris.

Choose a socket on any circuit and designate that socket as you "Test Socket". Using this socket each time to test your loop and RCD should give you around the same reading each time. If your reading starts to differ dramatically then you know your tester needs calibrating.

If the socket is RCD protected then you will only be able to test your loop on the No-Trip setting as the Hi setting will trip the RCD and you won't get a proper reading.

chrisgc · Jul 10, 2010

JUD said:
Hi Chris.

Choose a socket on any circuit and designate that socket as you "Test Socket". Using this socket each time to test your loop and RCD should give you around the same reading each time. If your reading starts to differ dramatically then you know your tester needs calibrating.

If the socket is RCD protected then you will only be able to test your loop on the No-Trip setting as the Hi setting will trip the RCD and you won't get a proper reading.

Hey JUD

How comes someone suggested when I asked about the loop and rcd test - suggested it be done on a non RCD socket?

Chris

JUD · Jul 10, 2010

chrisgc said:
Hey JUD

How comes someone suggested when I asked about the loop and rcd test - suggested it be done on a non RCD socket?

Chris

You would need a non-rcd socket to test the Hi loop test. As for RCD, how can you test that on a non RCD socket. I use a plug in type RCD to test mine as I'm still on a rewirable fuse board.

robskiing · Jul 10, 2010

Hey Jud if you ever need a price for your fuse board upgrade give us a shout lol

JUD · Jul 10, 2010

robskiing said:
Hey Jud if you ever need a price for your fuse board upgrade give us a shout lol

Thanks, but I was thinking about getting these guys to do it.

BBC - Watchdog: Our friends British Electric

Heard they're quite cheap

chrisgc · Jul 10, 2010

JUD said:
You would need a non-rcd socket to test the Hi loop test. As for RCD, how can you test that on a non RCD socket. I use a plug in type RCD to test mine as I'm still on a rewirable fuse board.

Jud,

So I am right in saying that to do loop test for my monthly checks on my MEGGER 1553 I just put the Loop dial onto NON-TRIP??

Also when doing my tests for the RCD I just put the dial onto 30mA as thats what it is on CU and then is doing the 1x and the 5x good enough or should I also include result for the 1/2x??

Chris

JUD · Jul 10, 2010

chrisgc said:
Jud,

So I am right in saying that to do loop test for my monthly checks on my MEGGER 1553 I just put the Loop dial onto NON-TRIP??

Correct

Also when doing my tests for the RCD I just put the dial onto 30mA as thats what it is on CU and then is doing the 1x and the 5x good enough or should I also include result for the 1/2x??

Just 1x and 5x. You shouldn't get a reading at ½x. If you do then the RCD is too sensitive.

Chris