Some background:
This past year I've been working at a theater in NYC that was built inside an old warehouse. This is a temporary space while a new permanent space is being built over the next few years. The lx setup is 12- and 6-circuit mult running from ETC dimmers along a grid of schedule-40 that is overhung on an I-beam support structure that is not original to the space. Approx 1/3 of our inventory is Source 4 ellipsoidals, 1/3 Par-56 and Par-64, 1/6 Source 4 pars, and a variety of older instruments including some 500W Fresnels and Mini-Tens, which we use as house lights.
The symptoms:
Occasionally the following things happen, especially during a bright full-stage cue or house light cue: The wireless comm buzzes so loudly that it is painful to use and overpowers the other voices; Video projection signal is interrupted with a rolling white line, whether Cat5 or VGA; A stagehand or electrician going up in a genie to the grid gets a static shock when they touch the grid (mostly in winter).
The solution?
A couple of video designers and other production people this season have recommended grounding the grid, but I have been looking for months for information on how to do this with very little success. We're in a city, which means the water pipes may work as a grounding rod, but we don't have an outside space (or unpaved ground) to put a grounding rod. There's no dark corner of the theater because the entire warehouse is essentially the theater, and the space is used very differently by different productions/directors throughout the season. Has anyone had a successful experience grounding a grid? What's the best metal to use? What's the best way/place to attach it to the grid? What if the water pipe doesn't do the trick? Is it even safe to use the water pipe?
This past year I've been working at a theater in NYC that was built inside an old warehouse. This is a temporary space while a new permanent space is being built over the next few years. The lx setup is 12- and 6-circuit mult running from ETC dimmers along a grid of schedule-40 that is overhung on an I-beam support structure that is not original to the space. Approx 1/3 of our inventory is Source 4 ellipsoidals, 1/3 Par-56 and Par-64, 1/6 Source 4 pars, and a variety of older instruments including some 500W Fresnels and Mini-Tens, which we use as house lights.
The symptoms:
Occasionally the following things happen, especially during a bright full-stage cue or house light cue: The wireless comm buzzes so loudly that it is painful to use and overpowers the other voices; Video projection signal is interrupted with a rolling white line, whether Cat5 or VGA; A stagehand or electrician going up in a genie to the grid gets a static shock when they touch the grid (mostly in winter).
The solution?
A couple of video designers and other production people this season have recommended grounding the grid, but I have been looking for months for information on how to do this with very little success. We're in a city, which means the water pipes may work as a grounding rod, but we don't have an outside space (or unpaved ground) to put a grounding rod. There's no dark corner of the theater because the entire warehouse is essentially the theater, and the space is used very differently by different productions/directors throughout the season. Has anyone had a successful experience grounding a grid? What's the best metal to use? What's the best way/place to attach it to the grid? What if the water pipe doesn't do the trick? Is it even safe to use the water pipe?