electric testing

[werner starbuck]

[h=1]Identify one item that needs to be disconnected prior to carrying out insulation resistance tests?[/h]here is another question that i'm not sure about. you can't disconnect the main earth as it is the resistance your testing, or ami wrong here.

 

[brman]

Given the wording I assume this is a 2391/5 question. So you are doing a full L-N, L-CPC, N-CPC test?

You need to think about what would happen to equipment connected to the circuit. Both in terms of how it might affect the result and what 500V might do to equipment.

 

[malcolmsanford]

Identify one item that needs to be disconnected prior to carrying out insulation resistance tests?

here is another question that i'm not sure about. you can't disconnect the main earth as it is the resistance your testing, or ami wrong here. Is that a another question or part of the what can I disconnect question

Why are you shouting?

 

[tony mc]

Have another good look at GN3 and then you will get it clear in your own mind !!

 

[MarkieSparkie]

Why are you shouting?

Insulation Resistance test blew-up his hearing aid!:lol:

 

[werner starbuck]

there are only four possible answers to the question.
1 sockets
2 switches
3 lamps
4 main earth

i have researched through all the study material and the only possible answer i can find is in the inspection and testing manual p74 411.3.11 onwards. it states that: 'insulation resistance tests should be made on electrically isolated circuits with any electronic equipment which might be damaged by applicationof the test voltage disconnected or only a measure to protective earth, with the line and neutral connected together.'

so based on this i think it should be lamps.

 

[malcolmsanford]

Your getting there son ............... now think what also could be on, lets say a light circuit that could be damaged by an IR test

 

[werner starbuck]

thanks for your help on this. i think i have it. if the sockets are disconnected and the switches on you would eb able to carry out the ir test without the risk of damaging any vunarable equipment.

 

[telectrix]

not only plug in equipment , but as malc. has said, any lighting with electronics, ballasts etc., can be damaged. if in doubt, link L to N and test to E.

 

[i=p/u]

and reduce to 250vdc for method 2

 

[trev]

Smoke alarms sometimes don't like 500V up em.

 

[tony mc]

250 v method 2 ?

 

[i=p/u]

ok talking poo, i knew somone was talking/telling me poo when saying that other night... he must of been looking at selv or something... forgive my blunder