Help with megger 1553 fault

[hoppy]

Hi,

my megger 1553 has been working fine until yesterday tried to do a numver of Zs readings on no trip, but kept coming up trp on the screen, yes I had all leads connected, also tried it at sockets with the plug and still same message.
My meter was calibrated in November and has only been used a few times since. Any ideas guys, is this an internal fault?

Thinking of contacting the calibration company.

All help much appreciated.

Thanks!!!!

 

[tony mc]

I take it that the mcb did not trip.

 

[ringer]

@hoppy Did you try this at any other properties, like your own house? What is the state of the batteries in your tester? Did you try it on 'High'? I have found (on my 1552) that sometimes the No Trip setting constantly stops at 'trp' but then the high current option works without tripping the rcd. Don't understand why this is, but have observed this behaviour on more than one occasion

@tony - why would the mcb trip? Did you mean to say the RCD?

 

[tony mc]

Having re read the post yes it would be RCD as he is useing the socket plug .

Sometimes on no trip a 6 A mcb would trip out when doing a no trip loop test.

 

[hoppy]

Thanks for the reply ringer, yes tried it a two other properties and still same error and I also changed the batteries, will try what you said and see what happens. Thanks.

 

[MeggerTSG]

Hi,

my megger 1553 has been working fine until yesterday tried to do a numver of Zs readings on no trip, but kept coming up trp on the screen, yes I had all leads connected, also tried it at sockets with the plug and still same message.
My meter was calibrated in November and has only been used a few times since. Any ideas guys, is this an internal fault?

Thinking of contacting the calibration company.

All help much appreciated.

Thanks!!!!

Hi hoppy

The MFT1553 may indicate 'trP' during a 3 wire no trip test. This can occur when the earth testlead probe momentarily breaks contact with the cpc during the test. The MFT assumes there is a power interruption, due to a supposed circuit breaker trip, and stops the test indicating 'trP'

However, you mentioned you have tried both the 3 wire leadset and the mains plug lead; the 'momentary break in contact' would not occur with the latter.

The 'trP' error can appear on a particular circuit if the circuit cpc is intermittant or a terminal screw on the cpc is not quite tight. Although the R2 or R1+R2 (200mA continuity) tests seem fine the low current no trip loop test can show 'trp' during the loop test.
This fault is not usually repeatable a different installations.

It maybe possible there is a MFT terminal contact issue within the terminal panel of the tester. This would require inspection by service personnel.

Kind Regards

Megger Technical Support

 

[BrockHaus]

I was also getting a Trp reading when conducting Zs tests. Very frustrating - eventually noticed it was only on the socket lead not the individual probes. After reading the above post I adjusted the contacts at the tester end of the lead and normal service was restored...