Polarity....

[matt.leung]

Been installing new downlights in a bathroom refurb..... went to test them (Zs) and discovered wrong polarity with voltage between N and E....

Went to the main JB and tested the main incoming feed in supply, all fine nothing wrong,

reconnected the switch line - standard T&E one way circuit, and the first spot light, and found that I then get voltage between E and N.... why would the switch line cause this.... all IR testing was fine....

headbang headbang headbang headbang

 

[apprentice87]

Cos you wired it up wrong???

john...

 

[matt.leung]

wired it correctly... could it because of the load on the circuit, and it is a fault further back down the line.....

 

[Andy™]

wired it correctly...

not if you have a voltage N-E

 

[matt.leung]

wired the bloody JB three times, step by step...

 

[Andy™]

well, as someone else once said, if you havent found the fault, you havent done enough testing

 

[matt.leung]

E-L = 35v...

L-N = 230v...

E-N = 18v....

 

[Andy™]

you must have a loose connection somewhere

 

[steptoe]

E-L = 35v...

L-N = 230v...

E-N = 18v....

so you have a potential on the earth?

or do you mean L-E 35v  ?????

 

[ProDave]

Floating earth.

 

[matt.leung]

floating earth??

 

[Sharpend]

Well if it's not at the jb then it must be elsewhere?

 

[kerching]

I concur with my steaming colleagues,,,,you have a floater

Just sleighing

 

[apprentice87]

Post a wiring diagram of how you did it...

What dead testing did you do before you livened it up??

What results you get when you tested the polarity and Zs at the board?? before you added the new bit?? What about when you inspected for bonding and earthing conductors being in place BEFORE you did any Zs testing

john...

 

[matt.leung]

new main earthing conductor was upgraded

new bonding to gas and water

Ze = 0.31 ohms

PFC = 1.10 kA

 

[ProDave]

R1, R2? or R1+R2?

 

[betty swollocks]

The correct answer has already been given, floating earth, probably in the bathtub, could be sink, more than likely before the jb you are connecting into.....

 

[SPECIAL LOCATION]

Incorrect testing procedures adopted by the sounds of it.....

hint...

DEAD testing comes BEFORE live testing!

:coat

 

[matt.leung]

R2 = 0.58 ohms

 

[Technician]

R2 = 0.58 ohms

So.....do an R1 + R2 and then test for polarity, dead, at EACH accessory

to ensure that the switch and the protective device are in the LINE conductor

only.