Zs test tripping RCD.

[markadams]

Hi, recently I have found that my Fluke 1653 has been tripping the odd RCD when doing a three lead Zs(loop) test. I can't understand why, it has not done this before.

 

[telectrix]

if your tester puts 15mA through for the test and there's inherent leakage of 8 -10 mA on the installation, it may well trip. do a ramp test first .

 

[Bait Account]

Do you test directly at the rcd with the load disconnected?

 

[ImpededLoop]

Do you test directly at the rcd with the load disconnected?

Not for Zs, that would be for RCD tests.

 

[Bait Account]

Not for Zs, that would be for RCD tests.

Lol sorry bud. Misread the question.

 

[Octopus]

Not for Zs, that would be for RCD tests.

But he could turn off the other MCB's on the same RCD!

 

[ImpededLoop]

Lol sorry bud. Misread the question.

No worries, easily done! [emoji1]

 

[ImpededLoop]

But he could turn off the other MCB's on the same RCD!

Yes, good thought. [emoji3]

 

[allybally]

I've had this before, it was a 100mA main switch RCD, on 2 of the circuits cooker and ringmain, the RCD would trip on loop test l, turns out a screw was put through the cooker cable with a dead short on N-E, or try a Ramp test, and I take it your on No Trip mode, goodluck

 

[R G]

Look on the plus side as well , now you've done the test with all circuits connected as well and found RCD trips , you now know theres a fault on one of the circuits or appliances , but as already said RCD tests are best done at the board as appliances such as fridges etc will give false readings anyway..

oops just re read the ops question , Zs testing not RCD ..still same applies ,

 

[TJ Anderson]

plug the blue lead in aswell