ZS testing without a No Trip function

[muffking]

Does anyone know if it's possible to do Zs testing of circuits with the Fluke 1653 below?
It's tripping the 30mA RCD when testing the circuits and the meter doesn't have a No Trip test function. Have I bought the wrong meter?

 

[securespark]

I don't think it does.

I believe you need the 1653B.

Link removed.

 

[EFLImpudence]

1652 is automatically no-trip when using all three leads.
I wouldn't think the 1653 is different.

Are you using the three-lead method - L, N & E?

 

[EFLImpudence]

1652 is automatically no-trip when using all three leads and set to L-PE.

 

[flameport]

Connect all 3 test leads
Select 'Loop' on the rotary switch
Press F1 until L-PE is displayed, and all 3 of the N-PE-L dots at the top of the screen are showing.

 

[muffking]

Thanks gents.
I'm new to Fluke and today is the first time I've a chance to use it properly, but I get the F1 setting which toggles between the L-PE 3 wire test and L-N 2 wire test.
I suppose my questions are what use is the L-N test when I'm trying to carry out an EFLI test. And why does the 3 wire test trip my neighbours board, but not mine when we have the same MEM board?

Pic below for reference is from when it didn't trip on the 3 wire test at home.

 

[chivers67]

It might mean their RCD is over sensitive, i'd do a Ramp test on it if they're ok with that. L-N is quite useful to ensure overcurrent protection is met for the MCB (on TT) though I'm sure others may give another reason or two.

Where's that measurement from?

 

[EFLImpudence]

I suppose my questions are what use is the L-N test when I'm trying to carry out an EFLI test.

L-N two lead is a high current test for the L-N loop (PSCC) but you can use it as a high current L-PE two lead test by placing the N lead on the CPC.

And why does the 3 wire test trip my neighbours board, but not mine when we have the same MEM board?

Ramp test the neighbour's RCD and see at what value it trips.

 

[JohnW2]

I suppose my questions are what use is the L-N test when I'm trying to carry out an EFLI test.

I suppose the simple and short answer tio that is that an "L-N test" is NOT an "EFLI test" (the clue is in the 'E', or 'EF', of EFLI) - so an "L-N test' is of no use to you at all if you are wanting to measure 'EFLI'

Kind Regards, John

 

[flameport]

And why does the 3 wire test trip my neighbours board,

Excessive leakage current on their installation, the low current test takes it over the trip threshold.

 

[Adam_151]

Excessive leakage current on their installation, the low current test takes it over the trip threshold.

Are the no trip tests on these testers actually low current? I always understood that these particular MFTs made use of the old robin D-LOK method, where DC is injected to disable the RCD while the loop test is done

 

[EFLImpudence]

Are the no trip tests on these testers actually low current?

Well the alternative is called hight current.

I always understood that these particular MFTs made use of the old robin D-LOK method, where DC is injected to disable the RCD while the loop test is done

I don't think so.

Not sure where I read it, but I think it just does the test so quickly that it doesn't give the RCD time to react - but presumably lower current than the high current test.

 

[muffking]

It might mean their RCD is over sensitive, i'd do a Ramp test on it if they're ok with that. L-N is quite useful to ensure overcurrent protection is met for the MCB (on TT) though I'm sure others may give another reason or two.

Where's that measurement from?

The measurement in the 2nd photo was from one of the ring sockets, although the Fluke shows 0v and no PFC when you disconnect the meter from the circuit.

L-N two lead is a high current test for the L-N loop (PSCC) but you can use it as a high current L-PE two lead test by placing the N lead on the CPC.


Ramp test the neighbour's RCD and see at what value it trips.

Good shout to use the 2 lead test on L-PE, although strange it didn't trip if it's a high current test, which I agree with as it's much quicker.
Ramp test on the RCD that tripped was 11mA

I suppose the simple and short answer tio that is that an "L-N test" is NOT an "EFLI test" (the clue is in the 'E', or 'EF', of EFLI) - so an "L-N test' is of no use to you at all if you are wanting to measure 'EFLI'

Kind Regards, John

Ha ha, got that. Just couldn't understand when I would want to know the L-N loop impedance, but I get the the idea.

Excessive leakage current on their installation, the low current test takes it over the trip threshold.

All the breakers were off and I was testing on the outgoing side of the RCD. I've changed their board now to dual RCD Wylex board and the Fluke is not tripping either of the new RCD's.

 

[EFLImpudence]

The measurement in the 2nd photo was from one of the ring sockets, although the Fluke shows 0v and no PFC when you disconnect the meter from the circuit.

Not sure about that

Good shout to use the 2 lead test on L-PE, although strange it didn't trip if it's a high current test, which I agree with as it's much quicker.

It should trip RCD.

Ramp test on the RCD that tripped was 11mA

A bit low, so either leakage current in circuit already or faulty RCD.

All the breakers were off and I was testing on the outgoing side of the RCD.

Breakers off does not disconnect N-E faults.
If you are testing at the RCD then you may as well switch it off and test the incoming side.

I've changed their board now to dual RCD Wylex board and the Fluke is not tripping either of the new RCD's.

Very good. Faulty RCD then ???

 

[muffking]

Thanks again.
I would be interested to know what the difference between the 3 lead L-PE test is compared to the later models No Trip test.