elec. power to a garden shed

[ondro]

Hello,
I have following scenario, 20A circuit breaker in the CU. 3 x 2.5 SWA cable feed to a garden shed CU. In the shed CU I have 0.69 ohm on the income cable. On the shed are two 16A radial circuits of socket outlet. When I do Ze on the sockets , I get 2.9 ohms.
The radial circuits have 2.5mm2 flat cable no longer than 5m from the shed CU.
Any idea why is the reading so high please?

 

[ondro]

Not good practice to have 2 RCDs in series

can have two RCDs influence to high reading of Zs please?

 

[Strima]

What's the R1+R2 of the circuits?

 

[Pete999]

can have two RCDs influence to high reading of Zs please?

Eh????

 

[buzzlightyear]

can have two RCDs influence to high reading of Zs please?

are you for real!

 

[Pete999]

are you for real!

Don't think so Buzz

 

[buzzlightyear]

I'm trying to get my head round this one .

 

[Pete999]

I'm trying to get my head round this one .

Not me mate I gave up at post 17 or thereabouts.

 

[buzzlightyear]

any body down their in the smokes (London) pop in to see what the op doing

 

[Midwest]

Eh????

Think OP is asking if two RCD's in series, be the cause of his high Zs

 

[westward10]

Not under fault conditions but with the Mickey Mouse soft test of a loop tester you may get inaccurate results.

 

[Midwest]

any body down their in the smokes (London) pop in to see what the op doing

He could ask that Thomas Nagy chap, he's from town.

 

[buzzlightyear]

I'm giving up the will to live now .

 

[Gavin John Hyde]

it is the perennial power to a shed post. there should be a separate forum on this site for anything to do with running power to a shed or garage. maybe we could make a lovely step by step diagram and guide on how to do it, how to test etc... as a week doesnt go by without the same questions cropping up. I do recall the IET and NAPIT making a similar guide a few years back - wiring matters? it was simple enough to follow, only thing is the diy'ers started getting to work causing chaos.

Theres an idea. electriciansforum pdf files or little guidance notes. all nicely branded and sold to folks out there... could be lucrative for the site!!

 

[telectrix]

time to get Kieron involved. a bit of filler cures all evils.

 

[telectrix]