Zs live Testing - does everyone do it?

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sdon26

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Zs live Testing - does everyone do it?

Or do you use a calculated Zs instead

 

paulh

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The zs test is probably one of the easiest and effective tests we do. It only involves plugging in a meter in most cases, where as an r1+r2 involves a bit of work disconnecting etc.

Anyway for me it is the test I always do unless I am working on a ups system.

 

davetheglitz

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I do live Zs for sockets - but for other applications - particularly lights I run out of hands to hold the test leads reliably - and find GS38 leads a pain - so tend to rely on calculated Zs.

 

mikel

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I do live Zs tests, it helps verify all my connections ae good:Blushing

 

extension15

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I couldn't imagine any self respecting electrician, not doing live tests...

:eek:

 

Admin1

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Welcome to the forum sdon26 - and congratulations on your first post.

Better late than never. :D

:p

 

davetheglitz

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I couldn't imagine any self respecting electrician, not doing live tests... :eek:
Interesting viewpoint ext - could you elaborate!

Do you have any easy ways of doing lighting circuits without significant juggling when trying to hold three test leads in contact and press a button when up a step ladder?

In a lighting circuit why is it so much better to do a live Zs than a Ze + R1 + R2?

Rings I understand and test literally every socket regardless.

In an inspection do you Zs test every lighting point - chandeliers, florries and all! If you do - respect, but how do you do it and remain competitive on prices? I test R2 to all of these as to my mind this is a risk area.

I consider myself to be a self respecting electrician but will not do a measurement that puts me at risk when there is no discernable risk to my customers.

 
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Dave

Testing lighting is not easy but I think it should be done. I usually do. I have them adaptors although I have not used them yet. Surely if you change a light fitting it is easier to do a loop test than take the lid off consumer unit to do a r1+r2 test.

Batty

 

davetheglitz

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DaveTesting lighting is not easy but I think it should be done. I usually do. I have them adaptors although I have not used them yet. Surely if you change a light fitting it is easier to do a loop test than take the lid off consumer unit to do a r1+r2 test.

Batty
Good point about changing the light fitting.

I've been thinking about the question on the lines of PIR's and personally see nothing wrong in the Ze + R1 + R2. In my experience my ze+R1+R2 reading tends to be slightly higher than the Zs - and if that's within spec I'm happy! I have never found a socket which passes by the Ze + R1 + R2 method and fails the live Zs.

I've been thinking of getting some of those lighting adaptors. Seem like a good idea!

Cheers

Dave

 

TTbangbang

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Zs live Testing - does everyone do it? Or do you use a calculated Zs instead
I think, not got notes with me right now, that you have to do live Zs for TT systems - you can't use calculation.

 

Admin1

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Good point about changing the light fitting. I've been thinking about the question on the lines of PIR's and personally see nothing wrong in the Ze + R1 + R2. In my experience my ze+R1+R2 reading tends to be slightly higher than the Zs - and if that's within spec I'm happy! I have never found a socket which passes by the Ze + R1 + R2 method and fails the live Zs.

I've been thinking of getting some of those lighting adaptors. Seem like a good idea!

Cheers

Dave
But you still need to take the fitting apart for R1+R2.

They cannot take an R2 reading.

There was even an article in the PE about it, last month or the month before.

 

jckent

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Just remember if you do zs on ligthing,make sure there isnt a dimmer connected. They don't like it much- strangely.......

 
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Just remember if you do zs on ligthing,make sure there isnt a dimmer connected. They don't like it much- strangely.......
Loop testing is all right through dimmers if you have a meter that only puts through a low test current through it. It the r1 + r2 I find doesn't work.

Batty

 
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Zs live Testing - does everyone do it? Or do you use a calculated Zs instead
welcome Guiness Drink

And Yes! do live Zs.......................

It is a good verification that your R1+R2's are good readings. ;)

Especially on a rewire or a new circuit...

can see NO reason why you cannot easily do Zs??? ?:|

 
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Just remember if you do zs on ligthing,make sure there isnt a dimmer connected. They don't like it much- strangely.......
Applaud Smiley;)

thats true...

even with the dimmer switched on full..

some meters give wobblies saying voltage is not there or polarity is dodgy and prevent a proper test being done! ;)

IMHO Dimers are probably one of the biggest pains when testing lighting circuits? :eek: :|

 

jckent

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many dimmers just shut down for a bit.

Did one the other day, went to zs the light forgot about the dimmer.

"Buggar" out the lights went , thought id popped the rcd, but no- the dimmer just shut off. Thought i'd killed it. But it came back to life after 30 secs. phew.

Also another reason someone may not do zs.

They are just lazy f****rs, or don't know what they are doing.

It's the easiest test and possiblly one of the most important, as others have said, it confirms what you have already measured.

 

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