Megger trouble - help

[Gerry24]

I have just blown the dust of my Megger MFT1553 and decided to run through some tests as I have a consumer unit to replace tomorrow. First one since passing my Elecsa registration .

Anyway, I have tried to do a Ze test and I can't get a reading. I am sure I am following the same procedure that I did previously.

Power off at suppliers isolator.
Leave main isolater swith on CU and all RCDs and MCBs swiched on.
Disconnect Main earthing conductor from earth bar.
Black lead to top hole in Megger labelled No Trip Loop
Green lead to middle hole in Megger which is labelled LO/L2
Red Lead to bottom hole in Megger which is labelled L1
Green croc clip on green lead and attach to main earthing conductor
Turn selector switch on Megger to No Trip LOOP
Red probe to line terminal in main isolator switch on CU.
Black probe to neutral terminal on main isolator switch on CU.
Press the yellow button on Megger.

Result is that the display keeps showing < 55 v and has the closed switch sign.

Am I making some stupid mistake (probably) or is my Megger kaput?

All advice gratefully received.

 

[Amp David]

You want to leave the supplies switch closed and open the CU main switch.

You aint got no volts if suppliers main isolater is off.

Don't do a no trip either if you haven't got an RCD on the tails

 

[Deleted member 9648]

Er....unless I'm reading your post wrong you have isolated the supply to the CU via the suppliers isolator and are then trying to do a live Ze test at the CU which is dead??.......that would explain the voltage reading your megger is showing.

Edit...Amp David reached the same conclusion by the looks of it.

 

[Deleted member 9648]

Gerry do you actually understand what a Ze test is? I ask as I cant see how anyone who does can attempt the test on a dead main switch....Sorry if this is not the case and not trying to be sarcastic, but if it is I think you need to have a bit of a gen up before undertaking anymore testing.

 

[telectrix]

ignorance is not stupidity, just a lack of knowledge

 

[jpmiff]

Hi,
if you cannot find your user manual for your megger you can download one from there site in the internet

 

[Deleted member 9648]

ignorance is not stupidity, just a lack of knowledge

Didnt say it was.

 

[telectrix]

i know that, just thought of it so was on this thread so thats where i said it. no offence meant

 

[Deleted member 9648]

none taken...

 

[Gerry24]

Thanks all for your comments. As I suspected, my error rather than the machine. Now I get it. You're right I do need to go over testing again as I haven't done any since my assessment.

 

[telectrix]

and if it's a good while ago, check your megger batteries.

 

[Deleted member 9648]

Thanks all for your comments. As I suspected, my error rather than the machine. Now I get it. You're right I do need to go over testing again as I haven't done any since my assessment.

Dont know if you have it mate but the IEE guidance note on testing and inspection is very good,tells you all you need to know.

 

[telectrix]

Christopher Kitcher's Guide to inspection and testing is useful.its even got pictures so even i can follow it

 

[Sav]

Christopher Kitcher's Guide to inspection and testing is useful.its even got pictures so even i can follow it

I got the same book. I even photocopied some of the tests and have it in my testing folder as backup !!

Also a good idea, and what I do. Every moth when the Professional lectrician magazine comes out, i tear off the advice pasges from NICEIC and megger etc and put them into relevent folders I have created at home. Now I have about 8 or 9 folders covering a lot of subjects which I can reger to.
this might be a good idea as well, its helped me so far.

Sav

 

[Sintra]

Have a read of this thread it might give you some help.

 

[mechelec]

This book is not cheap but it shows exactly where your probes need to go/links to insert and where etc highly recomended
Testing Electrical Installations: A Practical Guide for Electricians: Amazon.co.uk: Anthony Hinsley: Books

 

[Amp David]

This book is not cheap but it shows exactly where your probes need to go/links to insert and where etc highly recomended
Testing Electrical Installations: A Practical Guide for Electricians: Amazon.co.uk: Anthony Hinsley: Books

I got this book too and as you says for the actual amount of book you get its not cheap at all. The Christopher Kitcher's Guide book is miles better IMO and better value for money.

 

[m25maintenance]

hi, all if u av any megger problems, give megger in kent a bell, ask for help desk. they are very helpfull. iv used them a few times. numbers are on book in megger box