A Rather Bizarre Eletrical Occurance. . .

[technocracy]

Ok yesterday we were having intermitant power - obviously the power company were working on something. We have our own 50kw transformer directly connected to the high lines. I did all the eletrics in the house and they have been in use with any issues whatsoever for over a year.

So the power came back on and I went in my office and switch the light on (curtains were still closed) - the light came on then when off. At first I thought the power had gone off then I noticed my router still had lights on and my was happily watching TV. Hmmm I think must be the breaker for the lighting circuit - checked it - nope still on hadn't tripped.

I check the other lights on this circuit - nothing worked. Just to fill the background the light circuit covers in this order - pool room (as in snooker not swimming) - 3 light, my office - 1 light, a corridor - 1 light and the kitchen - 6 spots, fan with lights and extract fan.

First off - I take the cover off the Square D distribution unit check power levels on each phase (3 phase) all very healthy. Check the level on the breaker for the circuit also healthy.

I go to the first light on the circuit (pool room) check permanent power level - healthy! Started to get confused here! Ok - change the blub . . blub works. No other lights work on the circuit work.

Move on to the next light and check the power level - 0. I scratch my head (and backside) a bit and think ok disconnect the circuit from the power and buzz the whole circuit through. With a loop at the distribution unit I then proceed to buzz each fitting on the circuit . . guess what they all work!

So I connect the power back up and all lights except the 2 I hadn't changed the bulbs in the pool room worked. I check these bulbs both blown (all 3 are the compact energy saving type)!

Right I think and screw these 3 lights back on there mounts on the ceiling. I then check the other lights .. .. none worked . . you've guessed it except the first one. Ok power off checked the connections. I discover that one of neutrals (obviously the one leading to the next light) wasn't actually under the screw it was wedged between the brass connector and the plastic.

So I redid this connection put everything back to normal and all works fine!

Now what I don't understand is like I say everything has been in use for over a year without problems. Nothing was touched or moved so even though the connection was by no means perfect it was connecting fine.

So why would this cause the 3 light downstream to the power to blow and what could cause the connection to sudden fail even though nothing physically was touched?!??!

A very odd and frustrating 'problem'.

Edit: Bugger missed the c out of electrical in the title.

Edited August 4, 2008 by technocracy

[quiksilva]

Gremlins

[Khun Ngo]

Ghosts!

Run!!!

[soic]

I'd say it was caused by a minor voltage surge, the bad neutral is proabably what actually caused the bulbs to blow, a surge on one or two of the legs and not all 3 could have caused it, or even normal voltage on two and resistance on the neutral. Just a freak thing... one in a million. It wouldn't hurt to check the connections on your panel box as well.