IR Testing what is your take on it?

[Michael J]

Hi All

With the introduction of electronics into socket outlets and other devices. IR testing has become very laborious, I am only talking about EICRs, I spend more time looking for possible causes for low readings than anything else.
From another forum I gathered there was talk of doing away with the IR test.
What are your thoughts on this.

 

[farmerspark]

EICRs only require a global test between line and neutral linked together and earth. Does away with the issue of electronics affecting results, and possible damage to devices

 

[GBDamo]

I hear your pain but cannot see how you can do away with it.

 

[The Ghost]

My take on it is it is an ingenious method of assaying the state of cables in an installation. I eschew the global LN to E as I feel it is a very incomplete test and like to get into the installation more and know exactly what is going on. I am sure that is heresy but that is just me, curious and really want to be sure that when I say a circuit is safe to keep in use I know it is. I know there are instances where that is just not practical but still I will gravitate toward L-N L-E N-E where I can and yes I keep the earth in the earth bus bar!

 

[cliffed]

I always find it’s a difficult one,especially on Eicr,every schedule I’ve seen ,always got the perfect > 200meg ohms readings.
Domestic properties,no hassle,but offices etc with big TPN DB bit of a nightmare.

 

[TJ Anderson]

I only ever do IR L-L and L-N on initial verification. It is too disruptive and unnecessary for an existing install.

As far as testing periodically, For the breakdown to occur between those it would require 2 faults, which if there is a path between them, almost certainly there is a path to earth which you can pick up on LN-E test. That's would guide you to investigate further.

Cliffed. That's is soo true lol. All these 299 readings we see, which you know haven't even been tested due to what would of had to have been disconnected to achieve that.

 

[TJ Anderson]

I hear your pain but cannot see how you can do away with it.

Limitation on your report. As the inspector you can limit whatever you agree with the client.

 

[GBDamo]

I only ever do IR L-L and L-N on initial verification. It is too disruptive and unnecessary for an existing install.

As far as testing periodically, For the breakdown to occur between those it would require 2 faults, which if there is a path between them, almost certainly there is a path to earth which you can pick up on LN-E test. That's would guide you to investigate further.

Cliffed. That's is soo true lol. All these 299 readings we see, which you know haven't even been tested due to what would of had to have been disconnected to achieve that.

I'm going to take that sage advice, as I like the sound of it.

 

[GBDamo]

Limitation on your report. As the inspector you can limit whatever you agree with the client.

Not so much that one though, although I feel you could convince a customer of anything, I think it's a bridge too far.

 

[Michael J]

My take on it is it is an ingenious method of assaying the state of cables in an installation. I eschew the global LN to E as I feel it is a very incomplete test and like to get into the installation more and know exactly what is going on. I am sure that is heresy but that is just me, curious and really want to be sure that when I say a circuit is safe to keep in use I know it is. I know there are instances where that is just not practical but still I will gravitate toward L-N L-E N-E where I can and yes I keep the earth in the earth bus bar!

Great to see the English language used so eloquently. Your line , “I know there are instances where that is just not practical” sort of puts it back to having to use L&N to E method, which increasingly is the case.

 

[Marvo]

In the 'old days' before the widespread use of switchmode power supplies (chargers, PC power supplies, LED drivers etc) you could do an IR test and if you did a leakage clamp test around the supply live and neutral the results of both tests would tally.

Nowadays an global IR test gives little or no indication of leakage (functional or fault).

I'd only see the value of an IR test if you're fault finding or as a dead test on a new installation or circuit.

 

[Michael J]

In the 'old days' before the widespread use of switchmode power supplies (chargers, PC power supplies, LED drivers etc) you could do an IR test and if you did a leakage clamp test around the supply live and neutral the results of both tests would tally.

Nowadays an global IR test gives little or no indication of leakage (functional or fault).

I'd only see the value of an IR test if you're fault finding or as a dead test on a new installation or circuit.

I am coming around to that way of thinking as someone mentioned you often see 299MΏ on a EICR and you just know it's false.

 

[BLBelfast]

Nowadays with TPN boards filled with RCBOs IR testing is becoming a right headache. Disconnecting individually from each RCBO rather than a global test