Help Questions on IR of new consumer unit

[easysushi]

Gents

Just installed CU as part of my NICEIC eval next Tuesday, got a couple of questions regarding Insulation Resistance

When doing an IR on the entire installation at the CU, connect Neutral and line together to prevent damage to sensitive electrical equipment. IR test Earth and line/neutral, the reading I'm getting is 160MOhmz is that suffient for the test. I understand that the minimum is 1Mohm but should I not be getting >299 if i have disconnected all appliances and lamps etc.

Also what do I put on the Electrical Cert if I have only done method 2 of the IR test


Cheers


ty

 

[Risteard]

I understand that the minimum is 1Mohm

Have you not answered your own question there?

Further investigation if below 2 Megohms.

What's wrong with 160 Megohms?

 

[acat]

Reason for test quote 612.3.3 page 158 of BRB you will see on the same page 1Mohm is the min acceptable however 2Mohm is the standard your reading is way above that.


Chris

 

[Hawk81]

i would not be questioning 160Mohms sounds good to me

 

[SEC-Tom]

i would not be questioning 160Mohms sounds good to me

I think he was just thinking that it should be at the maximum scale that his tester is set on, that it shouldn't change really. Am I right?

 

[easysushi]

I know this is a thick question but how do you guys IR a consumer unit, I mean connecting the neutral and line together on each cirucuit do you draw a scrap bit of cable up from each circiut to the neurtal



Ty

 

[SEC-Tom]

Don't quote me but I think they link the live and neutral at the main sw. with a bit of cable then when testing between the busbar and and earth bar the neutral and live should all be linked...

 

[jmtisme]

Gents

Just installed CU as part of my NICEIC eval next Tuesday, got a couple of questions regarding Insulation Resistance

When doing an IR on the entire installation at the CU, connect Neutral and line together to prevent damage to sensitive electrical equipment. IR test Earth and line/neutral, the reading I'm getting is 160MOhmz is that suffient for the test. I understand that the minimum is 1Mohm but should I not be getting >299 if i have disconnected all appliances and lamps etc.

Also what do I put on the Electrical Cert if I have only done method 2 of the IR test


Cheers


ty

What does he on his cert when doing ir on method 2

 

[acat]

What does he on his cert when doing ir on method 2

612.3.3 page 158 of BRB

This is used for reason for live/neutral on one clip and earth on the other



Chris

 

[Merl]

Hi all!

Newbie poster, but been lurking for a while. A damned good forum for info on here with some very knowlegable people! I guess a lot of guys appreciate the advice they receive here. I know Iv'e picked up some very good advice and tips while looking in!

I guess the answer to what IR reading to put on the test schedule for line & neutral connected together tested to earth would be to fill in the LINE - EARTH column only and make a note of the reason in the remarks column at the end.

 

[SEC-Tom]

Hi all!

Newbie poster, but been lurking for a while. A damned good forum for info on here with some very knowlegable people! I guess a lot of guys appreciate the advice they receive here. I know Iv'e picked up some very good advice and tips while looking in!

I guess the answer to what IR reading to put on the test schedule for line & neutral connected together tested to earth would be to fill in the LINE - EARTH column only and make a note of the reason in the remarks column at the end.

Would you put LIM in the Line - Neutral test box?

LIM meaning Limitation.

 

[Merl]

Would you put LIM in the Line - Neutral test box?

LIM meaning Limitation.

Hi Tom.

It's possible! As LIM indicates that an inspection or 'test' was prevented from being carried out. Maybe Iv'e been puting the wrong info on the test schedule!!

Hope someone can clear this one up for me too then?

 

[easysushi]

Guys,

Is it the prefered method to IR test Live/Netural - Earth. Instead of breaking down the circuit and removing all devices attached


Ty

 

[ezzzekiel]

the correct procedure is to test each circuit individually and record results as they come, tying l/n together and testing to earth will test the whole installation and is usually done prior to new connection to supply or when electronic devices that may be attached to the installation cannot be removed. (this can also be done on a single circuit)

 

[easysushi]

the correct procedure is to test each circuit individually and record results as they come, tying l/n together and testing to earth will test the whole installation and is usually done prior to new connection to supply or when electronic devices that may be attached to the installation cannot be removed. (this can also be done on a single circuit)

So if you IR a circuit and you don't get the expected result in my case I expected to get >299 from my Megger instead got 160Mohm why would that be ?



Ty