Test lead current rating.

[Rampage]

I'm making up a green test lead to use with my Megger 1553 with a plug adaptor for PFC and Zs tests.

I have bought 3A silicon cable, I need to know what sort of current the Megger generates for these test to see if the cable will take it?

Thanks.

 

[telectrix]

think it's about 20A for Zs test ( hi current).

 

[GLENNSPARK]

I'm making up a green test lead to use with my Megger 1553 with a plug adaptor for PFC and Zs tests.

I have bought 3A silicon cable, I need to know what sort of current the Megger generates for these test to see if the cable will take it?

Thanks.

better off with 12AWG silicon cable...its about 2.5mm core and 4mm O/D will carry 30+amps will that...good for making up wander leads n all......

 

[tony mc]

On the Hi current loop on the 1553 it puts out 25A on the test!

The No trip puts out 15mA so the RCD is not tripped!

 

[Engineer54]

I'm making up a green test lead to use with my Megger 1553 with a plug adaptor for PFC and Zs tests.
I have bought 3A silicon cable, I need to know what sort of current the Megger generates for these test to see if the cable will take it? Thanks.

3A ?? Can you actually see the conductor?? What is the actual size of this conductor? Remember that multi stranded silicon cables have a higher current carrying rating than normal insulated cables....

 

[Rampage]

I thought it would be a higher rating too!
It's 0.5mm2, OD is 2.6mm.
I bought a long length to use the rest of it as a wander lead. Which should be fine, as its low current!
I might just buy a different length for the PFC lead.

I worked it out on the adibiatic and it will take the 20A current for 0.008 seconds! Anyone know how long a PFC test lasts on a megGer
Thanks.

 

[Rampage]

The last bit is a joke. I posted prematurely and can't edit it!

 

[GLENNSPARK]

well with all due respect mate you said it.....so you think that because the PFC is only for a very short duration that alls good?.....over time and continued tensioning of this cable you plan to use it will just end up wilting on you...in time...and probably when you dont have a replacement and need it to do its stuff.....test leads are a certain CSA for a reason mate and dont forget the smaller the CSA...the higher the impedence......

 

[Rampage]

Yes, I said it but didn't get the on the end to make it obvious it was a joke!
I appreciate that your saying. The resistance in the cable I bought is lower than my Megger test leads though. Also aren't you putting the same 20A through 1mm2 lighting circuits? And 5A rewireable fuses?

 

[WDMDL]

I use a Megger 1553. You can pretty much see the duration of the Zs test current if there are filament lamps in the house! Even when testing another circuit and you have a low Ze..
I'm going to take a stab at 40ms - 2 cycles.

Interestingly, there's one loading pulse on the high current test and two on the No-Trip test.
I know the blurb states 15mA for the no-trip test, but loading the circuit with 15mA wouldn't cause the short duration volt drops observed during the test.

Simon.

 

[Rampage]

I took the advice and bought some 32A rated silicon cable for the test leads.
The 3A silicon I will just use as a wander lead on a reel.

 

[ringer]

Would be interested to know where you got that silicone cable from and what kind of price it is.

Sent from my HTC Sensation using Tapatalk

 

[Rampage]

Had a reply from Megger this morning:

Hello Mr **cock
Thank you for your email
As such the MFT1553 loop test does not generate a current to inject into a circuit. Basically the unit introduces a resistance across the supply and the volt drop is used to calculate the loop impedance. The max current that flows is approximately 18A. The CSA of the cable is 1mm
Regards,

I never believed how the AA batteries could manage 25A anyway, but as a few people I asked said it could, I went with that!

ringer: from RS Components,
This is the 3A cable I used for the wander lead (2x lengths)

This is the silicon 32A (overkill!) I used for a green test lead

There's a cheaper version, which is 19A PVC (I think thats what the shiny standard Megger leads are. I can't find it on the internet but its from page 1-75 onwards in the 2011 catalog.