On the AM2 you just get a multimeter to use. There is a composite installation lighting, sockets, CH and solar, motor starter, fire alarm etc and you need to give the type of fault, Its location and rectification method.
I know about the half split method thats fine on radials but I just get a bit confused when it comes to more complicated circuit like the CH/ solar and the motor starter curcuit
I was lead to believe you only have access to a multimeter for the fault finding, but that wasn't the case (the AM2 documentation states that one of the intentions of the fault finding section is to ensure you are capable of using the most appropriate equipment). I had access to an AVI, an MFT, a phase rotation indicator and a data cable tester.
So if you've got a fault that reads "Problems were experienced taking insulation measurements", an insulation resistance tester is the most appropriate tool (I used the insulation test on an MFT for several faults).
You should remember that there are only certain types of faults... open circuit, short circuit, high resistance connection and mis-connection. So even if you do only have a multimeter available, you can identify these using the continuity (resistance) mode.
- Open circuit = No reading
- Short circuit = 0 (zero) reading
- High resistance = Reading above a few ohms
- Mis-connection = Continuity (0 or very low reading) between incorrect conductors (e.g. between L1/L2 at one end and L2/L1 at another with no connection between L1 and L2 at one end)
With regards to testing the heating system, you just need to think logically about it and learn a little about how the components work, like the connections on a motorised valve for example and what they do (Blue = Neutral to motor, Green/Yellow = Earth if present, Brown = Line to motor, Grey = Line to switch, Orange = Switched line return - So, to activate the valve the brown is connected to line, the motor runs up, opens the valve and at the end of travel closes the switch connecting Grey and Orange which will typically supply power to the demand input on the boiler/pump to engage the burners and start circulation).
So if for example you have a fault that suggests the heating circuit MCB trips when the heating program comes on, it's possibly a short circuit between line and neutral or line and earth on one of the components involved in that (room stat, programmer connections involved in heating, motorised valve, boiler and circulator). Just work through it logically one component at a time using the wiring diagram.
Hope this helps.
