Megger MFT1720 loop impedenace test issue

[krishcanag]

Hi

Happy new year to everyone.

I have mft1720 with megger fused leads protected by 50mA fused.

On Zdb (not main but garage unit) I wanted to do a Z measurement, set it to high current mode (L-L/L-N and Z) when I attempted to take a reading between live wires it blew the fuse in the Netural wire? I believe you must use high current mode for doing Ze or Zdb, so why should the fuse blow?

cheers

krish

 

[telectrix]

not sure exactly how you were doing the test, but sounds like you got something wrong.

 

[trypod]

GS38 compliant probes use 500mA fuses and have an appreciable resistance making them unsuitable when loop testing on live systems.

The fused lead itself will add a small variability into the test result.

Test leads fused at 10A will provide protection from short circuit faults but will not fail under normal testing conditions.

500mA Fused test leads (GS 38) order code 6220-789

10 A Fused leads order code 6220-827

 

[krishcanag]

Trypod, thanks man for this, I thought it might be something like this, so I will have to order the 10A fused leads, just wandoering if I could cheat and stick a 10A fuse in the GS38 leads I used?

krish

GS38 compliant probes use 500mA fuses and have an appreciable resistance making them unsuitable when loop testing on live systems.

The fused lead itself will add a small variability into the test result.

Test leads fused at 10A will provide protection from short circuit faults but will not fail under normal testing conditions.

500mA Fused test leads (GS 38) order code 6220-789

10 A Fused leads order code 6220-827