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#1 oscar jimenez

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Posted 06 April 2006 - 09:11 AM

Hello, Ive been asked for a Spider Box for an upcoming production, and Ive searched on the web with no luck at all, does anybody knows when referring to electricity or lightning what a Spider box is?
Thank you very much
Oscar
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#2 Barry Cheong

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Posted 06 April 2006 - 04:28 PM

I believe it's a bunch of 15amp edison/household outlet boxes mounted on a board. Someone might want to confirm that though...
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#3 Chainsaw

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Posted 06 April 2006 - 05:20 PM

Here ya go man...

Spider Boxes

These are just lug-based electrical distribution boxes. Expect to use these with 3-phase house power of some sort. They are referred to as "Spider Boxes" because of the copious amount of cables that (typically) extend from either side.

Obviously this site is for example and purchase only, for rental info contact your local grip/electric rental house. Don't sweat it if you haven't used them before, there really isn't much to them.
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#4 Hal Smith

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Posted 06 April 2006 - 05:57 PM

Make damn double sure the house power is 3 phase 120/208 volt wye, not 240/120 volt delta. Wye has three legs, each of which is 120 volts to ground and 208 volts between the 3 legs. Delta has 240 volts between each leg. But although delta has two legs that are 120 volts to ground the third leg leg (the "wild leg") is 208 volts to ground. In a delta system the wild leg is supposed to be color coded with orange wire or tape but I wouldn't count on it - measure each leg to ground or neutral of any unknown three phase circuit you're about to connect a spider box to. Almost every real stage or studio is wired 3 phase wye but I've run into delta in situations where the power company told me it was wye. :(

If you have to lug into a delta circuit, either don't connect to the wild leg or measure each spider box outlet and tape over any that measure 208 to ground
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#5 timHealy

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Posted 06 April 2006 - 07:41 PM

Make damn double sure the house power is 3 phase 120/208 volt wye, not 240/120 volt delta. Wye has three legs, each of which is 120 volts to ground and 208 volts between the 3 legs. Delta has 240 volts between each leg. But although delta has two legs that are 120 volts to ground the third leg leg (the "wild leg") is 208 volts to ground. In a delta system the wild leg is supposed to be color coded with orange wire or tape but I wouldn't count on it - measure each leg to ground or neutral of any unknown three phase circuit you're about to connect a spider box to. Almost every real stage or studio is wired 3 phase wye but I've run into delta in situations where the power company told me it was wye. :(

If you have to lug into a delta circuit, either don't connect to the wild leg or measure each spider box outlet and tape over any that measure 208 to ground


Where have you run into this sort of problem Hal? I have been a film elecrtician in NYC for over 15 years and have never come across this problem. I don't doubt it, I was just wondering where you have come across this. Typical unusual things here are trying to do a tie in in an old indsutrial building and finding 277/480 like voltages or finding boxes with 120/208 with no neutral.

Spider boxes aren't used too much here in NYC, but they certainly do come in handy if one is double or triple pumping runs of 4 ought to your set and breaking out from there. LA electricians may have some more comment on how a good distro systme they can be. One has to be persistant to get them here.

Best

Tim
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#6 Hal Smith

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Posted 06 April 2006 - 10:23 PM

Where have you run into this sort of problem Hal? I have been a film elecrtician in NYC for over 15 years and have never come across this problem. I don't doubt it, I was just wondering where you have come across this. Typical unusual things here are trying to do a tie in in an old indsutrial building and finding 277/480 like voltages or finding boxes with 120/208 with no neutral.

Spider boxes aren't used too much here in NYC, but they certainly do come in handy if one is double or triple pumping runs of 4 ought to your set and breaking out from there. LA electricians may have some more comment on how a good distro systme they can be. One has to be persistant to get them here.

Best

Tim

Small towns and cities in OK and TX tend to have electrical cooperatives and city owned power systems. For some ungodly reason they use a lot of delta - even the occasional open delta (two, not three transformers) which is a real bear to deal with, the open leg rarely is anywhere near the other two. I haven't run into delta in OKC, OG&E must hate delta as much as I do. I guess my basic caveat would be that anytime you get out of the big city, expect the unexpected!

My day job is radio broadcast engineering, I run a one-man consulting operation and probably half of my clients with transmitters that require 3 phase power and whose transmitters are out in the boonies have delta there. I really have had a coop employee tell me that a site had wye, ordered a surge suppressor for wye, and had the thing blow up when I threw the >delta< power to it. It was a good enough suppressor that it clamped down big time on the wild leg - and proceeded to sacrifice itself for the good of electrical surgekind. That's when I decided henceforth I would always haul out my Fluke and measure every 3 phase circuit before I hooked anything up to it that was expecting 120 to ground. :)

FLASH!!! I think I just figured out why these little power outfits use delta - probably their 3 phase originally was all open delta - that way they could distribute 3 phase power on three, not four, wires - two hot wires and one ground/neutral. They would have saved a bunch of money back in the 30's on wire and transformers.
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The Slider

Visual Products

Willys Widgets

Rig Wheels Passport

Tai Audio

Aerial Filmworks