2330 Practical question

Navbloke · Jun 18, 2009

I could really do with some help from a qualified spark who hopefully knows testing inside out or anyone who has passed the test.

I have got my practical exam coming up and due to reasons too many to go into i have a major question about the test board i am going to be using and I can't seem to get a straight answer from my college or get it straight in my head.

The main testing of rings, lights, radials etc I am ok with, but there is going to be a pretend garage fed from the main motherboard with SWA to a 2 way cons. unit with an edison screw lamp holder and switch and single radial socket.

My question is how do I go about testing the garage side. I know the ZE and PFC and bonding will be done form the main motherboard. I assume the polarity, CPC and Insulation resistance test will have to be done from both as well as the live tests. But what test, if any, do i do on the RCD from the main board for the SWA link to the garage? Thanks.

spraymate1 · Jun 18, 2009

Hi navbloke,
treat all the circuits the same, the swa to the second cu, just treat as a radial from the main board. when you do your ZS on this circuit, that reading will be your ze for the second board. (Don't forget you will have a seperate test sheet for the garage cu.)
As for your rcd test, just do the same as you would on the main cu, the test might trip the rcd on the main board as well, so don't forget to reset both. GOOD LUCK

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Navbloke · Jun 18, 2009

Many many thanks for the reply. Sorry to seem dumb, but I just want to get this straight. I treat the SWA as a circuit, doing the same tests as I do on a socket, switch, spur circuit etc. My continuity, CPC, RCD test etc are all done across the incoming Busbars in the second consumer unit?

spraymate1 · Jun 18, 2009

Yes mate, if you want you can disconnect the tails into the main switch, therefore you have a radial. then record your results for that circuit on the test sheet for the main board. then when all your dead tests are done on the main cu, then go to your garage cu, and repeat the dead tests for the rest of the circuits, when you energise the circuit for your live testing, make sure your main switch/rcd is off, as well as the mcb on the second cu.

Navbloke · Jun 18, 2009

Thanks very much, I really appreciate your answers. I feel a bit more confident going into the exam now. Just a pity I couldn't get a clear answer like this from the college or get to practice on a 17th edition board before the exam, instead of the 16th they have had us practicing on all year with a completely different installation. Cheers.