Basic Testing Procedures

[ejmoore]

Excellent thread! Got my 302 on wednesday ferifies what I have learned in class.

With regards to the ze test being 1st, we dont get taught this in class but my tutor always performs this test 1st, as she beleive's if its done later then you have not really confirmed continuity of cpc as the main earth has been disconnected for the ze test after the continuity of protective conductors. How can ya really be sure that it has been connected back satisfactory or not least forgot to connect it back( cuppa time maybe).

 

[bugsy]

let's hope posters actually bother to read this before asking silly question's and before anybody replies saying there are no silly question's well i'm sorry but there have been thank you sintra,

 

[ejmoore]

Sorry Bugsy but was my post silly!!

 

[bugsy]

Sorry Bugsy but was my post silly!!

NO and I dont wish to offend anyone ( especially those who post on this site to further their knoledge ) however in the past certain members have asked some questions which by looking through the sticky threads posted by Lenny Sintra and Acat would have answered their questions in depth, just makes me cross when someone goes to a lot of trouble and time to list these threads and people can't be bothered to do a bit of fishing- rant over

 

[ejmoore]

No offence taken, was thinking maybe I should take my self back to the kitchen sink for a while thou, lol.

 

[bugsy]

EJ my post was directed at supposedly " qualified electricians " not apps or students please do'nt be afraid to ask ,

 

[wade88]

EJ my post was directed at supposedly " qualified electricians " not apps or students please do'nt be afraid to ask ,

You see, i ask silly questions all the time, i never fear to ask, and that is because i would rather look like a ball bag on here then make a mistake in someones house and hurt someone.

look like a plum - no hurty
allow pride to interfere - big hurty

that in my opinion is why forums like this are invaluable to newbies like me. Thanks to everyone who suffers my silly questions on a regualr basis!

 

[Sintra]

Agree you are better off to ask than to put someone in danger. The only silly questions are the ones you don't ask.

 

[electromonkey]

Just joined this forum yesterday, I've read a few posts on here before via google but had a proper look on here yesterday and felt compelled to sign in.

That's a really simplified post concerning testing on here Sintra - better than any text book I've read!

A bit that caught my attention was where you had said how Insulation Resistance is a good indicator of the age of an installation. Could you elaborate on this please?

 

[Sintra]

On an istallation with new conductors you would be looking at an IR reading in the 100's of Meg ohms providing all of the connections are in order. As this installation ages the IR readings will fall as the insulation on the cable starts to deteriorate. So after 15 years you might be looking at an IR reading of say 20 Meg ohms. After 20 years it might be 10 Meg ohms and so on.

 

[electromonkey]

Cheers Sintra. That's a handy additional piece of info for determining ages of installations.

 

[Fender]

Is there any reason why a multimeter cant b used to test safe isolation? ie:voltage?

 

[Sintra]

A multi meter should not be used for safe isolation as it may be set in various positions.
For example you start of with it on the ac voltage setting but in the middle of the procedure you inadvertently move the selector to a different range which could prove fatal.

The reason the proper test equipment to GS38 should be used is to remove the possibility of human error.

 

[Fender]

Thanks m8, that was a recent exam question. My answer was that it wasnt an "approved" voltage indicator.

 

[1ManRiot]

Great thread. I've only recently begun my journey into the world of electrics (on a Network Rail apprenticeship) but I overheard some of the questions asked my by an interviewer to an interviewee, some of which are answered by this opening post, so I've printed this off for some bedtime reading!