Zs

[optician]

Hi, hopefully a quick question for you guys.
Can you take a Zs reading with electrical equipment
still connected to the circuit?

 

[Jurassic Spark]

Loop tester springs to mind.

 

[optician]

Sorry, not making myself clear.
Loop tester plugged in, other electrical equipment e.g. computer, still connected to circuit. Can you still take zs reading? with out damage to computer.

 

[spamwize2]

if u talking bout loop test then no.if u talking bout insulation resistance yea

 

[12345aob]

if u talking bout loop test then no.if u talking bout insulation resistance yea

Are you saying that Zs testing is dangerous to computors but IR testing is not?

 

[uksel]

would the test current run through the equipment plugged in?

considering the path of least resistance i would assume that the equipment would not be affected

thoughts...?

 

[LukeScotty]

i think uksel is right, all a zs reading does is find out the potential difference

 

[uksel]

if u talking bout loop test then no.if u talking bout insulation resistance yea

 

[optician]

Glad to see me question has got you thinking. Here are my thoughts, which are not necessarily correct.
Insulation resistance, which is not what my question was about, is 500v (dc I think) and will fry any semi conductors, computers and dimmers included when tested across phase and neutral.
Zs measured with a loop meter, measures impedance (not potential difference) of the phase and earth loop under fault conditions, a suitable low reading compared with the regs ensures quick opperation of the MCB.
A good earth path is required, so I think, the current generated by the loop tester follows the quickest route to earth, therefore, not affecting any computors or the like, still connected to the circuit?
I would be grateful if any one can confirm this.

 

[Spudnik]

Why would you want to test a circuit with items still connected?

Dont see it as a problem however, im not sure i would risk it myself, regardless.