Testing - practical exam coming up

[shocksl]

Hello good people

I haven't worked in the industry and I have DIY experience.

I am studying the course at York college.

I have a practical exam coming up. So i just want to get some practice in beforehand. Got a couple of months left yet.

I've made or should I say attempted to make a little sketch of the board will be.

The consumer unit will have RCD protection although this board doesn't seem to have it.

Can someone please kindly walk through how to do some of the tests. Especially on rlthe ring circuit.

Ofcourse once the safe isolation is done... I've turned off everything. Etc etc.

I'll perform the dead tests and then move onto live tests.

My idea is start off with continuity . Link
Cpc to live at breaker. Check all lightings etc sperarely switch lamp. Then move onto the heater .

Repeat with line and neutral.. how would i do the ring and bonding and the metal tray? ? Would it be long lead method?

Then once that's done. Move onto Insularion resistance at 500v. 3 tests on each circuit.

Then live and rcd. I've not really done this before. I'll need to read more on this one.

Any help would greatly be appreciated.

Thank you

 

[westward10]

Guidance Note 3 has step by step guides to these tests.

 

[Dan]

Moved to courses forum.

 

[shocksl]

I live in a flat. It says its protected by and RCD.. but I can't see the button . I'm assuming it'll be in the main consumer unit for the block ?

Judging by just looking at CU opened . It seems the kitchen sockets and the general sockets have 2 seperate rings as they have 2 sets of lines and neutrals coming into the MCB. And correct me if I'm wrong the larger neutral wires coming into the back of the MCB from the RCD ???

I might do some continuity checks tomorrow.

 

[shocksl]

So I've been playing about with it today! Did some continuity on the ring

My results were for the ring circuit.
r1. 0.65
rn. 0.65
r2 1.06

Sockets. I was getting in the range of 0.31 ohms and 0.33. I had to open the sockets up to check with positive abd negative probe. I'm sure my tutor said I could use the plug that is supplied with my MFT 1720 tester. But that wouldn't do it. Kept getting great than 999 with that.. so hence why I opened it up.

r1 +rn /4 ..indicates the results may be ok?

However when I did the cpc and line check with the probes at the socket. I'm getting 0.71 ohms. Not sure if this is correct?

P.s I have the switches on position

 

[PS Electrics]

I live in a flat. It says its protected by and RCD.. but I can't see the button . I'm assuming it'll be in the main consumer unit for the block ?

Judging by just looking at CU opened . It seems the kitchen sockets and the general sockets have 2 seperate rings as they have 2 sets of lines and neutrals coming into the MCB. And correct me if I'm wrong the larger neutral wires coming into the back of the MCB from the RCD ???

Test button is at the bottom of the RCBO with the T on it

 

[shocksl]

Thanks

 

[Jock from the north]

Yes this was throwing me off abit.

So in the consumer unit. I'm assuming there's going to be 2 links made?
Incoming line and outgoing neutral.
Outgoing line and incoming neutral.

For the ring circuit?

Yes but remember you also have to do the same with your R1+R2 ,now your earth might be smaller it just depends .these booths are crap beyond belief, they have students in every day so what tends to happen is the stranded singles get shorter and shorter every day and loose cores so you may not get the reading you expect, you never do.but the inspecter is only looking to make sure you have a grip /understanding on the sequence and varied results

 

[westward10]

The OP is using the correct terminology (r1 and r2) can we not confuse by incorrectly using R1 and R2.

 

[Jock from the north]

Yes this was throwing me off abit.

So in the consumer unit. I'm assuming there's going to be 2 links made?
Incoming line and outgoing neutral.
Outgoing line and incoming neutral.

The OP is using the correct terminology (r1 and r2) can we not confuse by incorrectly using R1 and R2.

Yes sorry