Zs tripping rcd

[Midwest]

Exactly, and you'd hope that anyone who is carrying out these tests would actually understand what they are testing and the basic principle of how the tester performs the test.

I don't understand the mindset of just pushing the test button and writing the number down, what does it really achieve?

Well I have to plead guilty there, but when something doesn't function as it should, there's always a reason. And in this case, I suspect the neutral-earth fault, somewhere.

 

[davesparks]

You'll know better than me, my manual for Loop Tests says, test current 4.0 A (at 230v) on Hi, and Pulsed on Lo (Megger 1730).

Not necessarily, I've only had the megger a few months and don't get much use out of it so am not so familiar with it as I should be.

The pulsed current I guess would be the 2 wire no trip?

 

[Midwest]

The pulsed current I guess would be the 2 wire no trip?

Pulsed current for 3 wire low & 2 wire low.

 

[davesparks]

Pulsed current for 3 wire low & 2 wire low.

Yeah I just read the manual, interesting.

I also noted how the manual talks about the possibility of RCD tripping even on low current tests, the possible cause and that an alternative method may need to be used.
I guess the OP didn't bother to read the manual for his tester!

 

[Midwest]

Your a bit harsh davesparks, most blokes get their new playstation out and connected it up. When it doesn't work, only then will they read the instructions. Still learning now with my MFT.

Never had a prob tripping RCD's on the low test currents, other than when I installed a luminaire for a customer and did a Zs test, for old times' sakes, and tripped the RCD. It was only going back to basics, did I find a neutral-earth fault on the circuit, re hum dinger!

 

[buzzlightyear]

jod35 just down load megger1730 pdf you will not go wrong . you should have cd with the new megger.and product card .

 

[Octopus]

Back to the OP - given its a 17th Ed CU, what does your tester do with the 2nd RCD?

 

[Dave OCD]

oops uploaded 3 times...... daaaaaan?

Ah isthis another Xmas quiz - spot the difference ? Well I can't find any...

 

[Dave OCD]

Odd, I thought the megger used 200mA with DC blocking on the low current test?

He's probably thinking of the half rated current 'no trip' RCD test procedure Dave.

 

[jord35davies]

Well I have to plead guilty there, but when something doesn't function as it should, there's always a reason. And in this case, I suspect the neutral-earth fault, somewhere.

Exactly what I think. But it definately is not internal.

 

[davesparks]

Exactly what I think. But it definately is not internal.

How have you confirmed that it is not internal?

Have you tested with the alternative Zs method?

 

[jord35davies]

Guys, I'm not new to the trade, I know what my meter is testing and I'm not just pushing the button and hoping for the best.
My meter does not give me the option of 3 lead test or 2 lead lest although it will carry out the test with two leads.
P-le on low or hi
And p-n on hi only.

I have been testing correctly. I came on here to see if anyone has came across anything similar

 

[jord35davies]

How have you confirmed that it is not internal?

Have you tested with the alternative Zs method?

Not yet Dave I'm there tomorrow and will keep you posted

 

[jord35davies]

Not yet Dave I'm there tomorrow and will keep you posted

I've tested every circuit individually from start to finish. Every circuit trips the rcd with no others connected. The cooker circuit even trips it with nothing connected. Ir shows up clear on every one. Get to zs and it trips

 

[jord35davies]

Back to the OP - given its a 17th Ed CU, what does your tester do with the 2nd RCD?

It is a 17th ed cu and if I'm testing a circuit covered by that rcd it still trips. Doesn't matter which circuit covered by rcd 1 or 2 it still trips.

 

[Octopus]

It is a 17th ed cu and if I'm testing a circuit covered by that rcd it still trips. Doesn't matter which circuit covered by rcd 1 or 2 it still trips.

That answer does not make sense!

Are you saying BOTH RCD's trip?

Have you tested your tester on another RCD?

 

[jord35davies]

Yeah I just read the manual, interesting.

I also noted how the manual talks about the possibility of RCD tripping even on low current tests, the possible cause and that an alternative method may need to be used.
I guess the OP didn't bother to read the manual for his tester!

Thing is Dave it's never happened before and I've tested many circuits/properties. Why now???? Why the 2 rcds????

 

[Octopus]

Have you got an earth clamp meter?

 

[jord35davies]

That answer does not make sense!

Are you saying BOTH RCD's trip?

Have you tested your tester on another RCD?

It doesn't trip the 2 rcds. It trips the rcd to which that circuit I'm testin is covered by. Make sense??

 

[davesparks]

Thing is Dave it's never happened before and I've tested many circuits/properties. Why now???? Why the 2 rcds????

Most likely answer I think is a N-E fault somewhere in the installation.
Unless it's got a different type of RCD installed, either an A or B type instead of AC?