Testig lighting circuits?

[liddley]

Whats the tactic when testing lighting circuits that have been wired using a central joint box?
When taking a Zs reading on a circuit that is wired in loop in I just find the last fitting on the circuit and take the reading from there. With the circuit in question its a small bungalow with the all lighting feeds, switch wires ect wired back to a JB in the centre of the loft space and all connections made off inside the JB. So all the switches light fittings are more or less equidistance away from the JB. I was just going to take a few sample reading from the light fittings and compare them? Am I right In doing this??

 

[telectrix]

sounds good to me. as you describe the situation, i assume that you have only switched line and neutral at the fittings, so you would need to take readings with switch/es closed.

 

[malcolmsanford]

Ahhhhhhhhhh the good old spider wiring.

Basically yes what you propose, you should as the good books tell us take your Zs from the furthest point, but like all testing there is a big difference from books to the real world.

If you have taken a several readings throughout the installation and they are basically the same then that is good enough. Though if you don't test all the points of utilization you can not confirm the CPC continuity.

 

[liddley]

Yes its only a small bungalow so testing all points is not a problem rather than sampling them.
Cheers guys

P.s Spider wiring would be a bang on discription of this old install!!

 

[malcolmsanford]

Liddley that was how I was taught to wire a domestic house,

Feed from CU into Adaptable box, din rail with klippons and then take it from there, I still think it is a good way to do it, as you just have a single cable at each light and each switch, and we all knew it as the spider.

I suppose it is just more time consuming so was faded out

 

[liddley]

Yes I like this way of wiring lighting also, I worked for a firm a few years ago who had the contract rewiring local authority housing in york. The council spec would not have the lighting wired any other way. And like you say its a bonus because you have minimal cables at yor fittings, comes in handy if your trying to fit cables into the small spaces behing wall lights and exterior light fittings! It used to be a compatition every day to see which one of us could make off the neatest adaptable joint box. we were a bunch a saddo`s. Never got to test them though cos they had an old guy that did all the testing work.

 

[malcolmsanford]

Careful Liddley if you enjoyed that your in danger of reaching my status the old grumpy fart.

I use to terminate doing a complete 360 degree loop on the cable, always thought that it looked neat, could always amp test it and had a little slack for the just in case, it becomes sad when you want all the loops exactly the same diameter

 

[liddley]

Oh no ,I already have cable O.C.D !!!