[SML] Electrical Wire thru Pulleys

[Duncan Mahoney]

I have done this many times for lightweight practicals, mostly operated at
120V.  My method is to get 3 conductor SO (NOT SJ) cable in a small yet
appropriate gauge for the load (usually 16 or 18) and some pendant rated
cord grips like Kellums brand.  Good quality blocks the proper size for the
cable diameter with a not-too-small D:d ratio are also important.  Common
issues to overcome are attaching the light fixture to the Kellums grip,
grounding a light fixture designed for only 2 wires, the weight of the
cable/rig on the offstage side of the block being heavier than the fixture
you are trying to raise/lower, and the cost of the long electrical cable to
get to the far side of the theater where the stagehand needs to operate the
rig.  If the dimmer connection is in the grid near where the light fixture
is suspended, clever use of mechanical disadvantage can save quite a bit of
electrical cable for the cost of another block and some small rope that runs
to the stagehand.  I have used this method on productions that ran for
years, with no problems with cable wear or breakage from flexing...but YMMV

Duncan Mahoney
Director of Technical Direction
Associate Professor of Theatre Practice
University of Southern California School of Dramatic Arts