Basic Testing Procedures

[macrylinda1]

Beg to differ here IMO the safe isolation must be done prior to the Ze test as you are removing the main earthing conductor to the installation. I stated that the Ze test had to be done with the supply switched off not that it was a dead test

The actual supply is not switched off, the installation past the main breaker is switched off granted but not the supply. Anyone just about to take the 2391 practical may be confused as books including GN3 and OSG use the CRIPLER method and this is the way i've been taught to test within my 2391 course;

Dead tests:

Continuity of circuit protective conductors
Ring final circuit conductor continuity
Insulation resistance testing
Polarity

 

[WayneL]

The actual supply is not switched off, the installation past the main breaker is switched off granted but not the supply. Anyone just about to take the 2391 practical may be confused as books including GN3 and OSG use the CRIPLER method and this is the way i've been taught to test within my 2391 course;

Dead tests:

Continuity of circuit protective conductors
Ring final circuit conductor continuity
Insulation resistance testing
Polarity

Except that you don't have to follow any particular order in the 2391, as it's a PIR that you are completing, not an Initial Verification.

You can basically test in the order that suits you best.

 

[RexT]

Hi Sintra,

Just want to say thanks for the useful post, I couldnt get to the thanks button.

Best wishes

Rex

 

[Stradders]

Reading that makes me want it even more!

Sad i know

 

[BillyBoBob]

Dead tests:

Continuity of circuit protective conductors
Ring final circuit conductor continuity
Insulation resistance testing
Polarity

Live Tests:

Loop impedance test external (Ze)
Earth fault loop impedances (Zs)
RCD testing

Just a note I was shown this and it really helped. It's vey similar.

C.R.I.P.P.E.L.D (main point to notice E & L are the wrong way round)

Continuity of C.P.C's inc main and supplementary bonding conductors

Ring final continuity

Insulation resistance

Polarity (dead)
>Earth electrode test if a TT system
Polarity (Live) inc phase rotation at origin of the installation

Externals Ze inc PFC at origin

Loop impedance Zs inc phase rotation and PFC both taken at the load

Devices inc RCD/RCBO and fuctional testing of both On-load and Off-load switching devices

 

[breakerman]

wounderfull stuff...

 

[breakerman]

thank you for a most usefull post

 

[RexT]

Hi BillyBoBob,

Thats a great comment probably originating from Chris Kitchen or a guy called Dave Potter.

Good stuff, good info.

Best wishes,

Rex

 

[Jurasic Spark]

Hi BillyBoBob,

Thats a great comment probably originating from Chris Kitchen or a guy called Dave Potter.
Good stuff, good info.
Best wishes,
Rex

The Dave Potter way is:

Continuity of protective conductors including bonding.
Ring continuity test
Insulation resistance tests
Polarity dead (normally already confirmed with C & R)
Polarity live (confirmation of supply polarity at live side of main switch before turning on)
Loop impedance tests, Ze or earth electrode followed by Zs readings.
Earth fault current and short circuit fault current (PFC)
Rcd and other functional tests.

The greens are dead tests and the reds are live.

 

[kangeroo]

good stuff mate its handy havin it online instead ov rummaging through books could u put the range on the tester like megaohms or that used for each sequence of tests up as well?

 

[solarpowerwales]

what a cracking post most helpfull as im just starting, could anyone help me on a template for a complaints procedure, before my eic assesment. cheers or possible send it pm me for my email address sorry if im being cheeky

 

[Mancspark]

Could any1 add what settings the megger should be on for each test please?

 

[glynnis]

Could any1 add what settings the megger should be on for each test please?

Easiest way is to read the instructions your meter comes with if you are unsure?

 

[ricosuave]

SafetyFirst, You forgot one of the P's in CRIPPLER, Polarity live

 

[taylortec]

hi like your thread did notice rcd did not cover testing both sides of the pos -neg half cycles of the supply waveform and the highest recorded

 

[Sintra]

hi like your thread did notice rcd did not cover testing both sides of the pos -neg half cycles of the supply waveform and the highest recorded

Thanks for that taylortec. Now edited with those included.


Sent from my iPhone using Tapatalk.

 

[obama6493]

some good stuff on there. it would have made my course a lot easier with a site like this to look trough and saved a small fortune on books mind i would have only spent it on tools

Sintra some useful info there for people like myself currently studying the 2391, however i believe the first part could be mis-informative to people who may have interpretated it as i have. Ze (external earth fault loop impedance taken at the origin) is not a dead test as described. Granted all outgoing sides of the DB main breaker should be open (in OFF position). However it is a live test and therefore will not be done after you perform a safe isolation.

 

[i=p/u]

good post for me anyway

 

[Sintra]

Sintra some useful info there for people like myself currently studying the 2391, however i believe the first part could be mis-informative to people who may have interpretated it as i have. Ze (external earth fault loop impedance taken at the origin) is not a dead test as described. Granted all outgoing sides of the DB main breaker should be open (in OFF position). However it is a live test and therefore will not be done after you perform a safe isolation.

I isn't described as a dead test. The test is carried out after the installation has been isolated safely so the earthing may be disconnected.


Sent from my iPhone using Tapatalk.

 

[wade88]

Excellent post buddy really helpful to refresh things over in your mind like this. Top banana

 

[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!

 

[almac]

Can these procedures be carried out by non electricians... I have my city and guilds pat testing and an HNC in electronics wondering if that makes me competent?

 

[leascliffe]

The actual supply is not switched off, the installation past the main breaker is switched off granted but not the supply. Anyone just about to take the 2391 practical may be confused as books including GN3 and OSG use the CRIPLER method and this is the way i've been taught to test within my 2391 course;

Dead tests:

Continuity of circuit protective conductors
Ring final circuit conductor continuity
Insulation resistance testing
Polarity

Live Tests:

Loop impedance test external (Ze)
Earth fault loop impedances (Zs)
RCD testing

Hi,

Thanks to Sintra for the original post! I agree with SafetyFirst, we were taught the CRIPLER method when I did the C&G2392 a few months back.

 

[ROY2612]

Thanks for the great info. Cheers

 

[brav]

Except that you don't have to follow any particular order in the 2391, as it's a PIR that you are completing, not an Initial Verification.

You can basically test in the order that suits you best.

yeah u can do polarity at the same time as continuity using Method 1.

Cracking posts tho lads

 

[WhiskeyDog]

Can these procedures be carried out by non electricians... I have my city and guilds pat testing and an HNC in electronics wondering if that makes me competent?

Hi Almac, Ive read elswhere that you need the 2391 to prove you are competent to carry out these tests, unlike PAT testing where it was argued you did not the C&G to carry out PAT.