ins res 40 meg

[Mr Mark Sparks]

doing dead testing today on a new installation 18 circs all>299 apart from outside lights i got 40 meg l-n and 100meg l-e & n-e went through the motions and found it to be a lamp holder in a tungston bulkhead removed lamp holder and disconnected it tested across lamp holder and it was giving these readings
(just a lamp holder on its own!!) anyone had anything similar

 

[Spudnik]

i knw wot im doin pal on a healthy circuit the reading goes full scale and reads 500v dc Mohms scale and reads 29.9Mohms the reading i was gettin was 3.71Mohms the and only went half way across the scale suggests i defect somewhere hence futher investigation needed ;-)

Nobody said you didnt know what you were doing.

We are simply trying to establish why you are getting 29.9Mohms on your meter "full scale".

Personally, i think you MAY have your meter set on the wrong scale.

Remember, YOU asked for OUR help. Which is what we are doing.

 

[iceman]

i jst checked me metre when i test on 500v dc the scale goes to 299M ohm when i test at 250v dc the scale goes to 99.9 Mohm i hope this has cleared up the confuison soz about tht ;-)

the problem i had the other day was on a lighting circuit upstairs when testing at 500 v dc the reading read 2.95mohms and only went halfway across the scale normaly when i get this reading it may suggest a lamps been left in somewhere but i removed everyin prior to testin i checked all the fittings lites switches and all the cable runs couldnt find a fault anywhere so i decided the cable was just old and needed rewire wot do ya recken?

 

[adamh]

i think your rcd isn't going to hold, if you've changed the board to the 17th

 

[iceman]

how do ya mean i tested the rcd 15Ma both cycles no trip 150Ma both cycles tripped 5.6ms 8.7ms respectivaly thn 5x rated current both cycles 5.4 ms - 8.7 ms respectivaly ;-)

 

[Guest123]

150Ma both cycles tripped 5.6ms 8.7ms respectivaly thn 5x rated current both cycles 5.4 ms - 8.7 ms respectivaly ;-)

Hi

For a 30mA RCD a 150mA test and a 5x test are one and the same thing. it should be half x, 1 x, and 5 x. 15mA, 30mA and 150mA.

Cheers

 

[adamh]

because that is almost a dead short which the rcd will pick up on

 

[pushrod]

i jst checked me metre when i test on 500v dc the scale goes to 299M ohm when i test at 250v dc the scale goes to 99.9 Mohm i hope this has cleared up the confuison soz about tht ;-)

the problem i had the other day was on a lighting circuit upstairs when testing at 500 v dc the reading read 2.95mohms and only went halfway across the scale normaly when i get this reading it may suggest a lamps been left in somewhere but i removed everyin prior to testin i checked all the fittings lites switches and all the cable runs couldnt find a fault anywhere so i decided the cable was just old and needed rewire wot do ya recken?

Have you looked in the attic for a loft light?

 

[lister]

Nice one pushrod, i've been caught out with the very same thing before.

 

[Spudnik]

Or possibly a TV booster?