When is 'method 2' acceptable??

[Trulyshocking]

Ok, without wanting to cause too much controversy, when is it acceptable to use method 2 for insulation resistance testing? The term 'when it is unpracticable' is lame IMO and invites lazy testers to forgo a lot of work that would otherwise be necessary. I have, however used it myself!! Would be interested to hear other members interpretations....

 

[jaresquire]

Never, for new installations IMO. For any other testing use it and if an poor reading is obtained then do the legwork.

 

[Sparky Ninja]

Can you refresh me on what you mean by method 2 for insulation resistance testing?

 

[Adam W]

Can you refresh me on what you mean by method 2 for insulation resistance testing?

Connect line and neutral together and test to cpc.

 

[Trulyshocking]

Can you refresh me on what you mean by method 2 for insulation resistance testing?

Yeah sure...
Connecting live and neutral together and testing IR to earth, therefore foregoing the need to through connect at every light fitting or point on a ring final circuit as mentioned in a previous post today...

 

[Sparky Ninja]

I thought so, but where is it worded as method 2?

It says in the regs when it is and isn't acceptable...

Furthermore..

On a new installing, it isn't acceptable also.

 

[Adam W]

What if you were testing something with a neon on it, eg some kind of appliance wired via FCU?
You'd always do type 2 with portable appliances so why not fixed equipment?

 

[tony mc]

I might be reading this post wrong but are you saying that testing Line & Neutral together to CPC should never be done on PIR when its aggreed as a LIM due to say rows and rows of low bay lights etc where you would need a cherry picker or the like to disconnect ???

IMO its in the GN for a reason and when it needs to be used (Test 2) its used but covered on the PIR!!

 

[IQ Electrical]

You might use it on a PIR on any installation other than the most basic domestic.The whole idea is to keep dismantling to an absolute minimum to avoid the introduction of faults from fatigued cable cores etc.

 

[Trulyshocking]

You might use it on a PIR on any installation other than the most basic domestic.The whole idea is to keep dismantling to an absolute minimum to avoid the introduction of faults from fatigued cable cores etc.

Interesting you say that.... my thoughts were that it was introduced to enable PIR's to be carried out more cost effectively, negating the need to hire in scissor lifts and the like for the loads of high bay light etc, but this whole question of causing more faults by carrying out dead testing during PIR's than actually finding faults is more on the money IMO. In the FM world, theres a lot of talk regards moving to more frequent 'live only testing' and I wonder if this is the way the world is moving.....

 

[IQ Electrical]

I see it moving towards live testing in conjunction with earth leakage monitoring in lieu of insulation resistance testing.It's all about minimising down-time as well as reducing maintenance costs.

 

[Electricalserv]

When it's not practical to dismantle an accessory that may give false readings!

 

[Trulyshocking]

When it's not practical to dismantle an accessory that may give false readings!

The problem I find with the '' not practical'' argument is that you are admitting to foregoing the electrical safety of a circuit in order to save yourself the inconvenience of dismantling a SFCU or unplugging a Rockwell.....

 

[Electricalserv]

Yes but you may by dismantling the accessory cause a fault within itself

 

[IQ Electrical]

Believe me, Guidance Note 3 makes these exceptions for reasons of safety, never with cost savings for the inspector/client in mind.

 

[IQ Electrical]

Since we were talking about the future of testing & inspecting, take a look at this system: The World's only addressable on-line diagnostic system for testing the fixed wiring of electrical installations | Test Marshal

 

[topquark]

Going the same way as electronics testing with a test access port. Distribution board assembly and maintenance work only to be carried out by qualified Test Marshal approved personnel though?

 

[brucelee]

Since we were talking about the future of testing & inspecting, take a look at this system: The World's only addressable on-line diagnostic system for testing the fixed wiring of electrical installations | Test Marshal

Hi Iq thats some system they wont need inspectors and testers soon lol

 

[IQ Electrical]

Hi Iq thats some system they wont need inspectors and testers soon lol

That's always the danger!

I'd like to see a few cost comparisons, especially on retrofit set against a full Periodic every 5-years for whatever life expectancy the installation has left.

 

[malcolmsanford]

Since we were talking about the future of testing & inspecting, take a look at this system: The World's only addressable on-line diagnostic system for testing the fixed wiring of electrical installations | Test Marshal

Nice bit of kit........................is it just a glorified BMS that now developed the software to read the circuit conditions.