I was wondering if someone who has done this exam would be able to tell me what certain faults will have on the test results. I don't have a job and have to do this exam in a couple of weeks and while I know how to test I am feeling very unprepared for it.
I know that doing CPC check will find all the breaks in the circuit but I'm worried that i'll get the reading and not know what to say for the fault.. just wondering if someone on here would be able to give me a few tips about what to expect (obviously can't tell me what faults i'll get) but some tips that might be able to help me along!
I can't explain things very well and I haven't taken the exam myself yet, but I'll give it a go.
You'll be told there's a fault on this circuit, and the RCD won't reset (just an example). Let's say it's a lighting circuit. You'd do an IR test, and probably find a low reading between L & E. Remember you're not expected to start taking the board to pieces, so you can't narrow it down to anything. You'll be asked to explain it ("this is an earth fault, the reading indicates continuity between L & E so whenever the circuit is energised the RCD will trip. To rectify I'd check the insulation hasn't been knicked by the screws in the accessory, and if that's fine then I'd start disconnecting parts of the circuit to find which piece of cable the fault is on, and replace it"). As I said, I'm much better in practice than explaining it so if anyone wants to correct me feel free!
You'll repeat a lot of your answers!
Edit to add more.
Is your board going to be live when you do it? If so you might be given an RCD fault. To find this you'd do a ramp test; it either won't trip, or will be too sensitive and trip too soon. To rectify this you'd replace the RCD/RCBO.
You might be given a motor. The fault with this will be either A) in the wiring to the contactor, or B) the wiring of the contactor itself. You should (I don't know if it's the same at all colleges) be given a wiring diagram for the contactor, and it's as simple as making sure it's connected up correctly. If this is OK then the fault will be on the wiring to the contactor. Apparently they'll energise the board and show you what the motor is doing to give you an indication of what/where the fault is.
Broken conductors, simple enough. The answer is "replace this bit of cable" after pinpointing the faulty length.
You might be given wrong polarity on an Edison screw, again this is simple enough.
