ECN Forum Forums General Topics of the Trade General Discussion Area variation in color of fluorescent tubes

Well I don't know everything yet and I haven't seen everything yet, but here's a new "first".
From a 120/240 single phase, 3 wire panel, circuits one and three sharing the neutral, circuit one feeding the inside lamps, and circuit three feeding the outer ones. Maybe I'm not understanding something correctly but it seems like that arrangement could be hazardous if something should happen to the neutral.
What I've done so far is put everything on one circuit and recommend electronic ballasts for the ten existing fixtures so that everything will be the same as the five fixtures I am adding.
Then there will be a total of fifteen fixtures,each with four 32 watt lamps for a total of 1920 watts times 1.25 equals 2400, divided by 120v gives me 20. The wire is #12 THHN and I pulled ground wires into the flex whips which were all steel and 8-9' in length.
Did I handle this properly? What would anybody have done differently in this situation?

Don'tknow;
without gettin' the good book out, i believe you must size per ballast, not element.
( probably because people can change an element)
then you should use the 80% rule for totals as applied to circuits.
yes, a shared noodle can have it's drawbacks, not that it's a violation. There is the consideration of the electronic ballasts vs. regular ones, i think they create more harmonics....

Don'tknow,

If you're putting things on 1 circuit I would check with the owner/tenant to be sure that's OK. The arrangement they had with 2 circuits supplying would allow them to only turn on 1/2 the lamps if they wanted to thereby saving $$$.

Bill

Most of the time that's true. Not always though. We recently completed a historical renovation of a county courthouse. As part of the renovation the flourescent lighting was demo'd and hid wall washers were installed. All of the 250w metal halide lamps were from the same manufacturer and the same type. The color differences were huge! Most were a nice white light....but many, probably %10-%15, were yellow. Very noticeable when they were mixed in the same room.

We rearranged the lamps so that the rooms were color matched then replaced the ones that we could not get to come out even.

All in all, a major hassle. Quality of materials seems to worse and worse as time goes on.....the obvious result when the job always goes to the low bid. Means we have to use low bid materials or not get the job.