Ze test on garage CUs

[electro]

hello every one!!! just a quik Q.

Q) when testing a garage CU do u take the Ze reading from the house or garage CU as the origin would b in the house??

 

[Lurch]

If the garage CU is fed from the house CU then the garage CU doesn't have a Ze, it's the Zs of the circuit that feeds it.

 

[electro]

because of the live is feed from the earting bar so classed as a circuit?? so on test shhet will i put down Ze measuring from the house ?

 

[electro]

i didnt mean live from earthing lol i ment the CU garage is clased as erthing from the CU in house there 4 if i measuerd the Ze at garage it would give me reading with all other circuits as will be conneccted

 

[Lurch]

Can;t work out the question in there I'm afraid.

At the garage CU the supply into it is a final circuit from the house CU, therfore the feed to the garage CU has no Ze, it is the Zs of the final circuit feeding it. You test it the same as any other Zs.

 

[electro]

yes that wat i ment, so on my cert i take Ze reading from house in comming L and E or leave it blank and take Zs garage sockets and lighting from cu in garage ?

 

[Lurch]

Nope, lost me again. What cert?

Re-read the above, I think you're missing something.

Ze - taken at origin

Zs - taken at end of final circuit

You need 2 sets of Zs readings, one for the circuit on the house CU feeding the garage, this is done at the incoming terminals of the CU in the gaarge. Then take a Zs for each of the final circuits in the garage in the normal way.

 

[electro]

ok, sorry bit confused bout what to test in the garage

ok test all circits r1+r2

IR

rcd of the garag unit!

Ze from house

Zs from circuits in garage

 

[Lurch]

On what certificate,, and why?

The Zs of the CU in the garage is missing from your list I think.

 

[electro]

ok and Zs from garage cu. its a new instaltion so needs a cert got asessment next week and he wants to c all certs i have done ?

 

[Lurch]

Yeah, I'd read up on testing if I were you.

 

[electro]

lol i am reading up on it just want to no what tests i do for a garage that is all need to get it rite in my head

 

[tom1]

test the garage circuits as you would a house, so ir, r2 or r1+r2, ring test if u have a ring zs and rcd. in the houes ze and pfc

if u have tt the garage then not sure if u do your ze there

the cable suppling the garage is a db circuit, so same test again

the zs is also your zdb

sorry my threads are all over the place, but then so is my head. give it a few mins and some of the great people here will correct my mistakes

 

[Andy™]

Ze: taken at point of origin

Zs end of circuit. your garage CU will be Zdb. this is generally Zs of submain, however, if you ditch the earth for a rod, your Zdb will be your Ra + any bonding and not Zs of submain

 

[bengie]

am i the only one who read the thread title in an allo allo nazi style?

 

[tom1]

[quote name='Andy

 

[tom1]

am i the only one who read the thread title in an allo allo nazi style?

 

[electro]

thanks for that it was what i thought if u had tt i would test ze from cu board as it would have its own earth path i think lol

 

[Evans Electric]

Yes, Ze tests vill be carried out !!

 

[tom1]

Yes, Ze tests vill be carried out !!