Insulation Resistance test

[The Godfather]

It is a good idea to test at 250v before putting the full 500v down the cable I always do this first it shows upm anything still connected before you damage it

50V would be a much better choice...

250V could still do some considerable damage.

 

[sirsparkabit]

As a matter of interest (to ME) ,I.R testing ring from socket outlet, P+N CONNECTED TOGETHER TO EARTH Main switch off all breakers on should i get a clear reading or will i still pick up loads connected. I do a lot of minor works small ext and conservatorys normally tapped into a ring and my certs demand an ri+r2 plus i/r ect i am looking for the easiest way of complying without hunting behind wardrobes ect and pulling conductors which are always in the wrong numbered terminals in the c/u. Before you go there i do know how to do this properly only trouble is i am losing an hour sometimes while peeps hunt for long lost loads or they have built in appliances they wont let me take out and some fool has put the s/o behind them?appriciate alll methods thanks s.s.a.bit

 

[steptoe]

TBH ssab I dont really think there is very often a valid enough reason not to be able to do a proper P-N IR test on a ring, I would be against the idea of putting a LIM on a ring test.

as for your Q, you should get a fairly clear reading this way, remember tho that your readings will be in parralell so will be much much lower than you would expect, still MUST be above 2meg tho.!

 

[sirsparkabit]

TBH ssab I dont really think there is very often a valid enough reason not to be able to do a proper P-N IR test on a ring, I would be against the idea of putting a LIM on a ring test.as for your Q, you should get a fairly clear reading this way, remember tho that your readings will be in parralell so will be much much lower than you would expect, still MUST be above 2meg tho.!

Thanks for your reply .

As this is a minor works most of the time i don,t have to do a full ring test ,however having said that i do normally split the ring at the s/o i am connecting into and do r 1 rn r2 to make sure it is a ring before i connect my tails in.

I have quite often had 10M ohm readings doing it this way but considering loads are connected assume that this would be much higher if they were not,what do you think? ssab? :|

 

[steptoe]

10Meg that way would be more than acceptable, Im assuming this is an existing installation (10+yrs),

the regs(I think) only ask for 10 or above before investigation, and that would be on individual circuits.

> 10M is more than good, so you can sleep well.

I really dont understand where some people get the idea of infinity being the only acceptable reading, meters dont even go to infinity,!!

personally on my certs I never put anything other than >50 in the box. unless obviously my reading is less than that, ie 15M :^O :^O

Ive even had individual readings as low as 6or7, old houses in poor repair, still acceptable tho.

 

[sirsparkabit]

It is anything around 2 M i think before investigation but i could be wrong?. I am thinking of going back to model certs instead of my scheme ones as the model ones don,t ask for a R1 R2 measurement which is not really nesassary on my extentions to existing circuits, i do my Zs and RCD tests though.

Thanks ssab

 

[Mr Sworld]

I really dont understand where some people get the idea of infinity being the only acceptable reading, meters dont even go to infinity,!!personally on my certs I never put anything other than >50 in the box. unless obviously my reading is less than that, ie 15M :^O :^O

Ive even had individual readings as low as 6or7, old houses in poor repair, still acceptable tho.

As I read it, it's unacceptable to put 'infinity' (or 8 on it's side ) on test certificates. You must always give a reading, even if it's '>999MOhm'

 

[cheggers]

put the heighest reading your meter reads and then put a plus sign afterwards my robin reads 200 and then goes off scale so I put 200+ on cert

 

[The Godfather]

As I read it, it's unacceptable to put 'infinity' (or 8 on it's side ) on test certificates. You must always give a reading, even if it's '>999MOhm'

As instructed, when taking the 2391 course.

499 or 999 as the case may be.

Don

 

[MR DIAZ]

It is anything around 2 M i think before investigation but i could be wrong?. I am thinking of going back to model certs instead of my scheme ones as the model ones don,t ask for a R1 R2 measurement which is not really nesassary on my extentions to existing circuits, i do my Zs and RCD tests though.Thanks ssab

I have always worked on < 2 Megas before investigation, that

 

[steptoe]

would agree, < 2M existing, <10M old,

but TBH any install should be able to hit 10M if its half decent at all.

 

[SPECIAL LOCATION]

I have always worked on < 2 Megas before investigation, that

 

[sirsparkabit]

I have always worked on < 2 Megas before investigation, that