Insulation Resistance test

Help Support Talk Electrician Forum:

taffyg1409

Junior Member
Joined
Mar 26, 2008
Messages
3
Reaction score
0
When faced with a lighting circuit containing 20 transformers for 50mm dichroics, which comes through a contactor and has 2 last man out switches, how on earth do you perform an I R test successfully without the obvious iv'e left something connected low readings????

Do you really have to disconnect every single transfomer bypass all the swithes!!

This would take for ever on a commercial property with 25 lighting circuits all with the above and batten fittings.

Somebody tell me there is a simple soulution or i'm going to hang myself!!! :eek:

Regards

 

the doctor

Part P Doctor ™
Joined
Mar 1, 2008
Messages
580
Reaction score
0
yep.

test n-e and l-e. dont bother with l-n....

perfectly acceptable, and record "lim" in the l-n box:D

 

taffyg1409

Junior Member
Joined
Mar 26, 2008
Messages
3
Reaction score
0
Lim meaning? 'limited' - 'limitation' - ??? Is this acceptable by the NIC??

Many thanksB)

 

Flying Scotsman

Electrician
Joined
Feb 15, 2008
Messages
468
Reaction score
0
yes i would think it would be

hey welshy when are you putting the yes and no smilie on here :^O :^O

 

Flying Scotsman

Electrician
Joined
Feb 15, 2008
Messages
468
Reaction score
0
oh go on welshy let us have yes and no pppppppppplllllllllllllllllllllllleeeeeeeeeeeeeeeaaaaaaaaaaaaaaaaaaassssssssssssssssssseeeeeeeeeeeeeeeee we'll be your friend for life.

:^O :^O:^O:^O:^O:^O:^O:^O:^O

 

extension15

Distinguished Member
Joined
Feb 13, 2008
Messages
1,659
Reaction score
0
On the subject of L-N Insulation Resistance testing...

Where it is not possible, basic continuity checking with a ohmmeter to verify load resistance (of concealed equipment etc) and more importantly to check for a short circuit..

B)

 

steptoe

of course Im wrong, ask my wife™
Joined
Feb 13, 2008
Messages
24,337
Reaction score
117
Location
Gtr Manchester
whoa whoa whoa guys

you must test between LIVE conductors and EARTH

this means PHASE and NEUTRAL, they are both LIVE

join the phase and neutral conductors together(use a block connector)

and test between these and earth,

only testing one of them at a time can potentially produce a voltage on the other thus frying the transformers, you MUST keep them both at the same potential.

 

steptoe

of course Im wrong, ask my wife™
Joined
Feb 13, 2008
Messages
24,337
Reaction score
117
Location
Gtr Manchester
On the subject of L-N Insulation Resistance testing...Where it is not possible, basic continuity checking with a ohmmeter to verify load resistance (of concealed equipment etc) and more importantly to check for a short circuit..

B)
oh, and totally agree with this, its a good refernce for your own peace of mind,

:D

 
Joined
Feb 14, 2008
Messages
7,480
Reaction score
21
Location
Cloud Cuckoo Land
whoa whoa whoa guysyou must test between LIVE conductors and EARTH

this means PHASE and NEUTRAL, they are both LIVE

join the phase and neutral conductors together(use a block connector)

and test between these and earth,

only testing one of them at a time can potentially produce a voltage on the other thus frying the transformers, you MUST keep them both at the same potential.
Yes, this is what GN3 states.

 

cheggers

Senior Member
Joined
Mar 24, 2008
Messages
198
Reaction score
0
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

 
Top