testing results

[james king]

hi all i am new here and i have been with my company now for 5months

today i was with my boss and we did some testing on a flooded house

we got a reading of 89.99 Kohms on the lighting circuit. he asked me what did i think it meant and to be honest i did not have a clue, i thought it was high.

he has asked me to find out for my self what this reading means

could anyone help please

 

[SKY]

Were the bulbs in the light fittings, if not could be moisture in the fittings.
I have known this in caravans before where its damp.

 

[james king]

no all bulbs taken out. i thought it may be a loose connection?

also the sockets had a IR test (i think) of 0.01mohm my boss jim said this is very low! again he ask me to find out what this could be and report back to him tomoro lol

i did not think r1+r2 test did not matter if bulbs were in or out!!! just on ir readings?

 

[rocker]

Do you know what test he was doing? Was it an earth continuity test, an insulation resistance test, or an earth fault loop impedance test?

 

[SKY]

OSG says lamps should be removed on R1-R2 test.

 

[james king]

he was doing an r1 r2 test on lighting he joined the live and earth together at cu

and carried out a ir test after that on the sockets. 0.01mohm is close to a short am i correct

 

[rocker]

Ah an earth contiunity test... as you say it's very high and I would say a loose connection or even a snapped conductor somewhere. I would do a long lead R2 test to ensure it is the CPC with the fault, not line (been caught out before). Then work from the end of the lighting circuit towards the board, testing each accessory on the way. This will show you which points the fault is between, and you can work from there. That's the first thing I would do (with the info provided)

That IR test reading is very low as well, but I would expect such a reading from a flooded house.

 

[telectrix]

if there has been a flood, i would assume the tests were IR ( insulation resistance). acceptable readings are in excess of 1.0 meg. anything loewer indicates a breakdown of insulation, probably caused by water still present in fittings. both the 89.9k and the 0.01 are unacceptable readings on an IR test. the solution is to thoroughly dry out all fittings, then retest. persistent readings below 2 meg. need further investigation. does not matter if light bulbs are in or out, but better remove in case the actual lamp is trapping water in the lampholder.

 

[james king]

after he finished the test he looked at me and said re wire i can see why as the house was messed up bad! but it rented and ppl need to live in it. so what else could cause a low ir reading??

 

[telectrix]

low IR could still be damp. the high R1+R2 indicates a poor connection somewhere. rewire is a bit drastic at this stage,

 

[rocker]

Well a low IR as you say is close to a short. If we take the water out of the equation, then in this situation we have poor CPC continuity and a high IR reading (presumably line-CPC reading?) which points to the same fault - a loose connection or a nail through a cable somewhere.

 

[james king]

no i think he ment a re wire of the effected lighting circuits. not whole house. cuz ppl need to move back in and can not wait for it to dry! he asked me ages ago how would i recify a high zs reading i for got bout that and he neva asked again but would like to know as u lot are very helpfull

 

[ezzzekiel]

being middle aged i struggle to understand text speak so tend to refrain