...On the other
hand,
most (not all)
touring or portable racks are just wired in numerical order with the first third on one phase, the second third on phase B and the third on phase C.
Not quite. The most popular
dimmer line in the world's touring racks are wired as follows:
ØA:1-8, ØB:9-16, ØC:17-24,
ØA:25-32, ØB:33-42, ØC:43-48.
Repeat the
pattern for 72- and 96-way racks. Ever notice the
dimmer holes are colored black, red, and blue in the
pin patch bay? See attached.
ML PDs are usually (but not always) wired XY: 1-2, YZ 3-4, ZX 5-6. A common mistake is when electricians make all their spare circuits either 6, or 5&6, as very few PDs have patchable circuits, thus guaranteeing the blue
phase will be "low".
McCready00http://www.controlbooth.com/forums/members/mccready00.html, see
this post regarding determining load of 208V moving lights.
Loads should be planned so that the lowest
leg is no less than 75% of the highest
leg. Obviously, one cannot balance
incandescent loads for every
cue, but one should avoid having all the frontlight on one
leg, all the backlight on another, the
cyc on the third,
etc.; as well as a three color
wash distributed as
Leg A,B,C. Only the
Master Electrician cares what the
dimmer numbers are, so this falls squarely on his/her shoulders. It's much more critical in a
portable situation, where one is dealing with
feeder in open air and Main
Circuit Breakers or Fuses of questionable age and reliability *cough*Hotel Ballrooms*cough*, than in a permanent installation, where one hopes a competant electrcial engineer has taken this into account for you.