Fault finding helpppppp

[Bradley6969]

Hi, did much AM2 a few weeks back and failed on fault finding, the test centre don’t give you much indication what you failed on but rang them up and was pretty close with 4/7 faults and you need 5/7 to pass, the faults I had were these,
Data - just plug in tester
Bonding - open circuit
16A socket - short circuit between L1-N
Socket ring - high resistance neutral on my spur socket

The ones I didn’t get were these,
Lighting - 2 way and intermediate works but not as it should do? Strappers wrong way round perm live and switch?
DOL - was open circuit on incoming L2 to top of DOL starter I messed up and put open circuit but also put needs new DOL which they couldn’t give me any marks
Heating - boiler and pump run constantly? Heating or hot water valve?

Wondering if anyone could give me any answers to what I could of done to solve these as I pretty close and gutted about as I passed everything else, I know the faults change next time but would give me more understanding
Thanks

 

[DPG]

Lighting - 2 way and intermediate works but not as it should do? Strappers wrong way round perm live and switch?
DOL - was open circuit on incoming L2 to top of DOL starter I messed up and put open circuit but also put needs new DOL which they couldn’t give me any marks
Heating - boiler and pump run constantly? Heating or hot water valve?
Thanks

Lighting wiring incorrect - should be able to confirm correct connections of strappers visually at the switches

DOL starter - sounds like you got this one right, just not sure why you also put that it needed a new switch?

Heating - check voltage feeding pump and see what is causing it to be permanently on, eg. wiring fault, short circuit, stuck valve, etc.??

 

[The Ghost]

It's kinda hard to answer your question(s) For instance what about the thermostat causing the problem on heating? the lighting could be something else like supply at wrong terminal or terminated incorrectly or cable fallen out, switch defective. But of course this is just speculation. When you say the two way lighting is not working as it should what do you mean? And how did you approach the investigation?
or as @DPG has said for heating. Does sound like you went too far in saying new switch for DOL. If it is (the circuit supply) open that is the problem.
Sounds like you were feeling rushed and did not have time to think it through. Seems as if you were almost there sorry you just missed. I expect next time you will fly through.

 

[Wilko]

A common fault in HW/CH is a valve sticking, perhaps simulated as the microswitch either perm open (no heating) or perm closed (boiler runs outside timer settings). Good hunting

 

[Bradley6969]

Lighting wiring incorrect - should be able to confirm correct connections of strappers visually at the switches

DOL starter - sounds like you got this one right, just not sure why you also put that it needed a new switch?

Heating - check voltage feeding pump and see what is causing it to be permanently on, eg. wiring fault, short circuit, stuck valve, etc.??

Yeah I think on my lighting they had a strapper and common swapped
DOL starter I was rushed for time and made a stupid mistake
Heating your only allowed a low ohm meter so will just have to bell everything out making sure no open or short circuits I suppose

 

[Bradley6969]

It's kinda hard to answer your question(s) For instance what about the thermostat causing the problem on heating? the lighting could be something else like supply at wrong terminal or terminated incorrectly or cable fallen out, switch defective. But of course this is just speculation. When you say the two way lighting is not working as it should what do you mean? And how did you approach the investigation?
or as @DPG has said for heating. Does sound like you went too far in saying new switch for DOL. If it is (the circuit supply) open that is the problem.
Sounds like you were feeling rushed and did not have time to think it through. Seems as if you were almost there sorry you just missed. I expect next time you will fly through.

I think on the lighting it worked but not as a 2 way and intermediate which would make me think yes it was incorrectly wired but I was rushed for time and didn’t get it right
Yes I went to far with DOL i should of just said open circuit on L2 of incoming supply from board to DOL replace with new cable and retest and thanks hopefully will pass it next time

 

[Bradley6969]

A common fault in HW/CH is a valve sticking, perhaps simulated as the microswitch either perm open (no heating) or perm closed (boiler runs outside timer settings). Good hunting

Thank you never done heating system before but I’ll hopefully get it

 

[Strima]

On the test boards there are only wiring faults, not accessories. So your heating fault would be a short between the conductors feeding the switch, which would be repair or replace as required.

 

[DPG]

Oy, 'M Aung' - why the dumb rating for my post?

 

[HandySparks]

Oy, 'M Aung' - why the dumb rating for my post?

It's a bit odd. A few times recently, the 'Dumb' button has been pressed by various members with minimal posts. I think the button should be removed.

 

[I2C]

I found that they can be really specific on some points:

Lighting - 2-Way / Intermediate
- If the strappers are the wrong way round, were the light-switches in the 'off' position when the lamp was off?
I was picked up on this, the top part of all the light-switches should be depressed when the lights are turned off. Also, just to make sure, check reversed-polarity between line & neutral just in-case (the lamp will still work but not to regulations)

DOLS - Direct On-Line Starter
- I was nearly fooled by this during my assesment! In my case, the "stop/off" button was mechanically faulty (the plastic pin between the physical button and the switch-mechanism had snapped and din't function / too short). Otherwise, perform all tests as normal to check continuity etc.

Heating / Hot Water
- What type of heating/hot-water system is it? A faulty 2-port valve would likely be stuck in one position, possibly caused by the limit-switch? If the motor has gone, depending on the type of motor, check the coils for continuity maybe. Hard to say without seeing it myself.
- I'm not 100% sure, but perhaps check the switched-line and permanent-line to see if they have been reversed. I'm not completely sure, but worth checking.

Other Notes:
- The examiners are very particular about wording regarding faults. Make sure your terminology is correct, such as:
- Open-Circuit between (line-neutral)
- Short-circuit with negligible impedance between line-neutral
- Earth-Fault with negligible impedance between (line-earth, neutral-earth)
- Examiners seem to dislike the word "faulty", they say that if it's faulty then you need to fault-find. If you've found the fault and a piece of equipment is not functioning - it's damaged/broken (not faulty because you've found the fault).

 

[ry12345]

Lighting wiring incorrect - should be able to confirm correct connections of strappers visually at the switches

DOL starter - sounds like you got this one right, just not sure why you also put that it needed a new switch?

Heating - check voltage feeding pump and see what is causing it to be permanently on, eg. wiring fault, short circuit, stuck valve, etc.??

It’s all dead tests nothing is live and no loose connections…

 

[DPG]

It’s all dead tests nothing is live and no loose connections…

Err, not even sure what I was replying to - it was 4+ years ago.

 

[7029 dave]

Err, not even sure what I was replying to - it was 4+ years ago.

Bump maybe lol

 

[i=p/u]

Il jump in anyway, As for heating staying on, if I remember right, it is a short between perm live and switched live, keeping heating on..