continuity test problem

[Bob Pay]

Hi, I have installed a small ring circuit which on continuity tests gives a problem. Rl,Rn and R2 all give acceptable readings of 0.6, 0.6 and 1.1 ohms respectively. Rl + Rn fine 0.04 ohms but as soon as I test Rl + R2 I get >200, which to me suggests an open circuit. Cable and sockets have been replaced but still with same results.
Any suggestions ?
Happy days Bob

 

[malcolmsanford]

You haven't slipped over to the IR scale

 

[Bob Pay]

Thanks for your reply, but what do you mean by IR scale? Bob

 

[malcolmsanford]

Insulation resistance that >200, is remarkably like an insulation resistance result for an healthy circuit.

What meter are you using??

 

[Bob Pay]

Hi, thanks, no I am still in cont mode, the meter is Di Log 9083P

 

[malcolmsanford]

Have you livened the circuit yet? It seems your still doing the initial verication here, and your dead tests.

Me I would make sure you have good Insulation resistance so no nasty bangs, then put a supply on and do your Zs see what that tells you.

 

[Bob Pay]

Have done, all tests in order dead and live, socket tester proves ok and supply works without problems. The meter is brand new. Maybe I should check out the meter. Thanks for you help,

 

[malcolmsanford]

Then as you say looks like it is the meter. Have you someone you can lend a meter off to try. If not contact Di log and tell them what is happenig and ask them

 

[Risteard]

Your cpc resistance at near double that of the live conductors sounds very high.

 

[DurhamSparky]

hey bob!! are you using the Plug on the test leads to test the circuits after setting up for R1R2...!! reason i ask this is i have same meter and when i set up for it and go round the socket fronts with the lead with the plug on i have to place Red End to Red Connection on meter and GREEN end to BLACK connection on test meter and leave the Black one disconnected..!

 

[swparksey]

As Durham said, make sure you swap the leads on the tester so that continuity is between R1 and R2, this is the most common cause of this if you are using a 3 lead tester or a Banana lead with a Plug.

 

[Lee85]

Your cpc resistance at near double that of the live conductors sounds very high.

How so? If its wired in twin and earth it sounds about right to me....

 

[Risteard]

How so? If its wired in twin and earth it sounds about right to me....

1.67 times would be about right. Almost double is very high.

 

[Risteard]

1.67 times would be about right. Almost double is very high.

Just calculated it and 1.67 times 0.6 is 1 ohm so perhaps not quite as bad as it sounded to me initially.

 

[telectrix]

last post seems to be the answer. can't comment on di-log though as i use megger. DOH, missed 3 posts. was meant to be answer re connection of leads