Teach me - Floodlights!

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sellers

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ok, so been doing a job re-lamping, replacing damaged ballasts and ignitors on a local floodlit sports centre. The jobs fine replacing like for like except winching down the towers is starting to get to my back.

Anyway I just wondered if anyone could explain the setup within these lamp-posts as I did ask quite an experienced guy at work and he hadn't seen it before either.

Take one lamppost with 6 x 2000w SON HQI-T floodlights on.

The incoming is 4 3phase swa's. No neutrals. Each one to an 3 phase isolator (4 again). This then splits up into 6x2 phase 45a MCB's. (Never really seen a 2 phase mcb)

Out of these the 2 phases then go throught the ballast, ignitior (with a capacitor tapped off it) then upto the light.

My questions are, how do you have 2 phases on a lamp. No neutrals, etc. Just after a bit of indepth information really.

O)

 
Sorry I dont think they're sons, more metal halide. Allthough Im not 100% clued up on lamp types.

 
And any Two (2) Phases = 400 V, as you know, Sir. :D

 
Just struggling to comprehend how a lamp can take 2 phases. They must be balanced to have no neutral, right?

these are the lamps

Osram%20Powerstar%202000w%20HQI-T-I%20lamp.jpg


 
Just struggling to comprehend how a lamp can take 2 phases. They must be balanced to have no neutral, right?these are the lamps

Osram%20Powerstar%202000w%20HQI-T-I%20lamp.jpg
your connecting between 2 phases, no neutral is needed. think of how a delta transformer is wired - each of the coils in there can be replaced with a ballast. they do not need to be balanced

and that lamp looks like SON

 
they do not need to be balanced
It's the old potential difference... they need to be out of ballance (on different phases) to make a circuit.

 

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