domestic fault diagnosis

[reedsinthewater]

Hi

I'm currently coming to the end of my three years training and due to take my inspecting and testing exam and my fault diagnosis exam. I'm fine with the inspect and test but we have hardly touched upon fault diagnosis , I was hoping you lovely people could put forward some domestic fault scenarios and then the stages of diagnosis that would be attached to these faults

Q. An example being, testing for R1 and R2, no reading at lighting point. A. Test cpc and neutral at point to see if cross polarity exists, if no then do insulation resistance test to see what conductor has open circuit

Any help would really be appreciated

Thanks.

 

[mattmoo1974]

Flick the switch to the ON!

 

[ezzzekiel]

if no reading on R1 R2 beetween s/l and earth check fom loop and earth (to miss out switch) if still no reading but all lights in property are on then you have lost cpc.

either drop each fitting and search for it, or find last light with a reading and between there and the next light is the break

 

[Deleted member 9648]

Hi

I'm currently coming to the end of my three years training and due to take my inspecting and testing exam and my fault diagnosis exam. I'm fine with the inspect and test but we have hardly touched upon fault diagnosis , I was hoping you lovely people could put forward some domestic fault scenarios and then the stages of diagnosis that would be attached to these faults

Q. An example being, testing for R1 and R2, no reading at lighting point. A. Test cpc and neutral at point to see if cross polarity exists, if no then do insulation resistance test to see what conductor has open circuit

Any help would really be appreciated

Thanks.

An insulation resistance test is not going to help you find a break in continuity....do that with an low range continuity tester.
When you have found and rectified the break in continuity THEN carry out an IR test to confirm satisfactory insulation resistance.

 

[jakeb]

An insulation resistance test is not going to help you find a break in continuity....do that with an low range continuity tester.
When you have found and rectified the break in continuity THEN carry out an IR test to confirm satisfactory insulation resistance.

hi, i was wondering if you someone may also be able to help with a question.

-state the possible cause for total loss of supply but c.b's and rcd's have not operated

-the rcd protecting the garage trips?

homework questions

thanks

 

[telectrix]

-state the possible cause for total loss of supply but c.b's and rcd's have not operated . ​power cut

 

[Top Cat]

First rule of fault finding:- check the easiest thing first (fuse, switch) and work your way up to the hardest fault you could ever imagine. 9 times out of 10 it's the easiest! Also ask questions to the customer and he will give you all the clues you need (unless he is lying to save face!)

 

[jakeb]

what tests should i carry out?

 

[jakeb]

i thought so, just wanted to make sure.

Also another silly question, state the possible cause for a number of appliances on the downstairs ring cct have been damaged simultaneously??

sorry about the silly questions, just fault diagnosis is a weak subject

 

[telectrix]

i thought so, just wanted to make sure.

Also another silly question, state the possible cause for a number of appliances on the downstairs ring cct have been damaged simultaneously?? lightning? dodgy IR test

sorry about the silly questions, just fault diagnosis is a weak subject[/QUOTE

my suggestion in red

 

[Guitarist]

Fault-finding is an art which takes years of practice. Someone here telling you the answers will not hone your skills.
During my apprenticeship, one of the senior engineers would recreate a fault on a machine which wasn't needed for production, then get me to work out where the fault was. Sometimes he would break a conductor inside the insulation, sometimes just fit a blown fuse. Whatever the fault was, I spent many an hour scratching my head with a multimeter in my hand.