couple of questions

[nicsin02]

awrite guys just a few wee questions

1. at work there is a transformer fed direct from a 3-phase breaker, when testing IR can i test it from breaker or do i have to disconnect from transformer? would the 500v damage the transformer?

2. was testing Zs at a start stop 3-phase isolator, it was only a 4-core cable so earth was obtained with the armour gland, when i was testing one of the phases to the lock ring there was a small arc and a small chard mark on the lock ring, is this normal, lock ring was solid and i got a good Zs for all phases?

3. when your looking to see how many points are on a circuit, is a double socket 1 or 2 points, is a spur and outlet 1 or 2 points, is a light switch a point, if a light has 4 bulbs is that 4 points?

Thanks

 

[Edd]

1, Yes test from MCB, and No shouldnt damage Transformer, but a little vauge on the infomation.

2, It will arc if you dont hold the conection tight. I blew a hole through a kitchen sink when I was an apprentice! so dont panic.

3, Thats open for interpritation. I take its current using items. So a light is 1 a switch doesnt count. a sw spur controlling a socket is 1, a cooker pannel with socket is 2. (one for cooker one for socket) a twin socket is counted as one.