Ze and PFC reading?

[Noob2013]

Hi all,

Im about to start the 2nd year of my apprenticeship and have been practising my testing at my parents home. I have a query on some results.

The Ze reading was 0.00 ohms and the PFC was 10kA. It's a PME Supply.

The Ze seems too low, does that mean that is is a very good reading or something is not right?

Also, does is the PFC reading ok?

Thanks in advance.

 

[mtfpuk2011]

did you discount the main earyhing conder from met as you do not wanna any parrl earth paths for the ze as its the total extral earth path

 

[Noob2013]

Yeah Main Earthing Conductor was disconnected.

Would the reading not get higher if the main earthing conductor was connected?

 

[chrish_1977]

How far away are you from the local transformer?

 

[Noob2013]

I'm not too sure how far away

 

[Dubbo]

Meter not reading accurate or you live next door to the sub

 

[telectrix]

@ 10KA, the Ze will be around 0.02 ohms. your meter will probably see this as 0,00. to get round it, either don't null the leads and take off their res. after, or use a few metrews of cable then deduct that.

 

[Dizzy_Maskell]

10ka what are the MCBs etc rated at just a thought

 

[Des 56]

Read this

http://www.electriciansforums.co.uk...38-higher-accuracy-low-ze-test-procedure.html

 

[Noob2013]

Thanks for the replies.

The Mcbs are rated at 6kA so they need to be changed then.

 

[rattlehead85]

Not if the main fuse is a 1361 rated at 60 or 100a as the upstream breaking capacity of these is 33ka.

 

[Jay Sparks]

If the fuse type is unknown, its better to assume the breaking capacity is 16.5kA. The fuse could be a Bs 1361-1 or a Bs 88-6. But in the OPs case, the 10kA is still lower than the 16.5kA.

 

[Noob2013]

The fuse is a 60a bs 1361.

 

[Dubbo]

BS1361 type1 16.5ka type 2 33ka

 

[sparky351355]

Did you zero your leads properly, daft question but I've seen it many times