IET
Decrease font size
Increase font size
Topic Title: Why do we insulation test (Perspicacious don't comment)
Topic Summary:
Created On: 12 May 2009 11:20 PM
Status: Read Only
Linear : Threading : Single : Branch
1 2 Next Last unread
Search Topic Search Topic
Topic Tools Topic Tools
View similar topics View similar topics
View topic in raw text format. Print this topic.
 12 May 2009 11:20 PM
User is offline View Users Profile Print this message



SKElectrical

Posts: 1142
Joined: 01 February 2009

Do we really need to Insulation Test our cables? Why not just turn breaker on? (I can see the reasoning of IR testing if sensitive / equipment is to be used)
 13 May 2009 01:23 AM
User is offline View Users Profile Print this message



truss

Posts: 1250
Joined: 27 March 2005

Originally posted by: SKElectrical

Do we really need to Insulation Test our cables? Why not just turn breaker on? (I can see the reasoning of IR testing if sensitive / equipment is to be used)


Eh?

What if a cable had been damged, but not to the extent that it operated the breaker? Just give it the "bang" test and if it don't go bang then it must be alright!

What about a N - E fault on a non-RCD protected circuit? Would your bang test discover that?

And what if you had to add an RCD to an existing circuit (with an existing N - E fault) after carrying out some minor works? Better to IR test the circuit before you start your alterations / additions rather than the bang test at the end.

Only yesterday i discovered a damaged cable on a re-wire by insulation testing. Luckily enough the decorating is some way off being finished so it was relatively pain free to replace the damaged section of the circuit.

Do we really need to Insulation Test our cables?


YES!

regards,

trussy
 13 May 2009 08:21 AM
User is offline View Users Profile Print this message



normcall

Posts: 8533
Joined: 15 January 2005

"Just give it the "bang" test and if it don't go bang then it must be alright!"

Ahh, the good ol' days!

-------------------------
Norman
 13 May 2009 09:03 AM
User is offline View Users Profile Print this message



perspicacious

Posts: 7890
Joined: 18 April 2006

First paragraph on p10, first definition on p22, Appendix 6 p331 (iv) all might give you a clue

Regards

BAD
 13 May 2009 09:22 AM
User is offline View Users Profile Print this message



Legh

Posts: 4164
Joined: 17 December 2004

IMO
For new installs and re-wires
1/ I would have thought the cables are tested before any
equipment is installed ?
2/ Cables insulation does get damaged when being installed and should be checked before commissioning.
3/ The occasional cable slips through the Cable manufacturers QA systems. - this has happened to me!
4/ It would be foolhardy not to IR test a MI cable after each termination.

For PIRs etc
1/ Plastic cables and accessories do deteriorate due to the ingress of moisture, dirt and grease, as well as the effects of heat, overload and abrasion.

Its not the IR tests but maybe the IR testing that needs to change?

Legh

-------------------------

http://www.leghrichardson.co.uk

de-avatared
 13 May 2009 08:43 PM
User is offline View Users Profile Print this message



mikejumper

Posts: 2542
Joined: 14 December 2006

Originally posted by: SKElectrical

Do we really need to Insulation Test our cables? Why not just turn breaker on? (I can see the reasoning of IR testing if sensitive / equipment is to be used)


Have you recently completed a domestic periodic report SK?
If so, I can understand why you've posed that question.
 14 May 2009 12:26 AM
User is offline View Users Profile Print this message



kj scott

Posts: 2144
Joined: 02 April 2006

Insulation testing does need re-thinking; the current requirements do not really meet with practical application; and PIR are at best limited tests; also the requirements of 612.3 are contradictory. IR testing as 7671 and GN3 will not find many serious faults.
 14 May 2009 01:30 AM
User is offline View Users Profile Print this message



Phillron

Posts: 1411
Joined: 18 January 2007

I would like to commend the topic originator on his question
When someone asks the question "why"
It portrays an inquisitive mind who will question accepted methods
He probably was aware that the topic would reap the typical answers even if they are probably correct
Not accepting the advise that is considered saccracint and "this how it is supposed to be" has made mankind move forward in great leaps throughout time
If all characters went with the flow,where would change arise from

Well done for the question
 14 May 2009 02:55 AM
User is offline View Users Profile Print this message



SKElectrical

Posts: 1142
Joined: 01 February 2009

Yes i am carrying out PIRs. Do i IR test everything - NO.

Do I ALWAYS write LIM on test sheet - NO. tut tut tut naughty me.

So who will put their hand up and take their spanking off the perfect Perspicasious?

I think this test will become redundant. The elders regard it as an all important test because its the only one they did as apprentices! In all honesty, in the context of commercial and domestic installations, it is far from the most important test.

(Fancy making a result up - i bet i'm the only one - i bet suppliers wouldn't dream of it - i bet you shudder - i bet you think i wire showers in 1.0mm...)
 14 May 2009 08:59 AM
User is offline View Users Profile Print this message



kj scott

Posts: 2144
Joined: 02 April 2006

I don't write LIM; I describe the extent of testing that I will be undertaking. If a test can not be practically carried out it does not make it a limitation. See 621.2 'appropriate tests'.
 14 May 2009 08:46 PM
User is offline View Users Profile Print this message



MrAmps

Posts: 386
Joined: 11 December 2006

You obviously dont work with carpenters and paslodes?



 14 May 2009 09:48 PM
User is offline View Users Profile Print this message



poo

Posts: 246
Joined: 07 May 2008

If the circuit has RCD protection and MCB protection then I don't think it is an important test.You can waste time looking for a "fault" that is only a small load you did not disconnect. Who has not done that? Very good question.
 14 May 2009 11:08 PM
User is offline View Users Profile Print this message



kj scott

Posts: 2144
Joined: 02 April 2006

Mr Amps; explain yourself sir?
 11 January 2018 09:35 PM
User is offline View Users Profile Print this message



dustydazzler

Posts: 1959
Joined: 19 January 2016

In America and Canada they don't IR test (well not that I am aware of)

Quite handy for fault finding mind
 11 January 2018 09:36 PM
User is offline View Users Profile Print this message



dustydazzler

Posts: 1959
Joined: 19 January 2016

Originally posted by: SKElectrical

Yes i am carrying out PIRs. Do i IR test everything - NO.



Do I ALWAYS write LIM on test sheet - NO. tut tut tut naughty me.



So who will put their hand up and take their spanking off the perfect Perspicasious?



I think this test will become redundant. The elders regard it as an all important test because its the only one they did as apprentices! In all honesty, in the context of commercial and domestic installations, it is far from the most important test.



(Fancy making a result up - i bet i'm the only one - i bet suppliers wouldn't dream of it - i bet you shudder - i bet you think i wire showers in 1.0mm...)


Glad I'm not the only one
 12 January 2018 07:23 AM
User is offline View Users Profile Print this message



Fm

Posts: 1820
Joined: 24 August 2011

....Because the appropriate regulations advise that testing should be carried out- So it gets done
 12 January 2018 08:59 AM
User is offline View Users Profile Print this message



dustydazzler

Posts: 1959
Joined: 19 January 2016

And IF , IR testing was omitted from the next lots of best practice guides would everyone be screaming blue murder that it has been removed ?

Or swinging from the rafters with glee that we have now got a slightly easier life
 12 January 2018 11:04 AM
User is offline View Users Profile Print this message



tomgunn

Posts: 4027
Joined: 25 May 2005

Good olde days indeed! Hahaha!

Not forgetting our good old bell sets!

regards!!

-------------------------
Tom.... (The TERMINATOR).

handyTRADESMAN

Castle Builders
 12 January 2018 11:29 AM
User is offline View Users Profile Print this message



SKElectrical

Posts: 1142
Joined: 01 February 2009

This post is 9 yrs old!! C'mon!
I test properly these days.. when I'm on the tools.
Although now its Volt drop constraints that really big me.
 12 January 2018 02:20 PM
User is offline View Users Profile Print this message



ToniSM

Posts: 381
Joined: 21 November 2006

Originally posted by: dustydazzler

In America and Canada they don't IR test (well not that I am aware of)



Quite handy for fault finding mind



The NFPA-NEC 2014 doesn't stipulate IR testing so it's down to the bang test. "No smoke, it's good to go".

-------------------------
The reports of my death are greatly exaggerated.
Statistics

New here?


See Also:



FuseTalk Standard Edition v3.2 - © 1999-2018 FuseTalk Inc. All rights reserved.

 
..