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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => HistoryOfConcertSound.org => Topic started by: Richard Turner on February 03, 2015, 01:00:53 AM

Title: random electrical related question
Post by: Richard Turner on February 03, 2015, 01:00:53 AM
Just a random question.

Back in the days of yore, How much AC was actually needed on those big fully rigged par can overloaded staged in the 1980's I'm guessing the equivalent of blocks worth of suburban houses. Or a shipyard...

Seems outrageous considering most bar rigs could be fed with 2 15A circus these days.

Title: Re: random electrical related question
Post by: Lee Buckalew on February 03, 2015, 06:17:54 AM
Just a random question.

Back in the days of yore, How much AC was actually needed on those big fully rigged par can overloaded staged in the 1980's I'm guessing the equivalent of blocks worth of suburban houses. Or a shipyard...

Seems outrageous considering most bar rigs could be fed with 2 15A circus these days.

In most touring cases that I am aware of 1000 watts @ 120 volts per PAR can.  Once we got to the pre-rig truss days a "standard" rider request was for 96 pars in pre-rig so, 96,000 watts. 
Title: Re: random electrical related question
Post by: Jerome Malsack on February 03, 2015, 09:37:57 AM
So calculated cost would be.
Title: Re: random electrical related question
Post by: Ivan Beaver on February 03, 2015, 01:02:20 PM
So calculated cost would be.
That assumes the lamps would be left on for the whole show.  Most are not  The actual consumption over the event would be much less
Title: Re: random electrical related question
Post by: Tom Bourke on February 03, 2015, 04:13:47 PM
So calculated cost would be.
plus the peek current draw fee.  We don't get that at home but business like venues and factories get charged a fee related to peek demand.  The monthly power bill will be several times that calculated amount.
Title: Re: random electrical related question
Post by: Tim McCulloch on February 03, 2015, 04:39:32 PM
plus the peek current draw fee.  We don't get that at home but business like venues and factories get charged a fee related to peek demand.  The monthly power bill will be several times that calculated amount.

Yep.  At our downtown arena they rented a really big genset (think 53' semi trailer) and hooked it into the water chillers.  They fire it up to start the chillers and then take it offline.  The reduction in peak billing paid for the genset a couple times over, I'm told.
Title: Re: random electrical related question
Post by: Richard Turner on February 03, 2015, 10:19:30 PM
Yes Yes, I can do the math on the theory.

Real life, everyone on light and sound aware of what was going on what kind of generation was needed/provided. ex, no full blind scenes tonight cause you will lock the armature in the gennie and brown out the show.
Title: Re: random electrical related question
Post by: Jerome Malsack on February 04, 2015, 03:14:29 PM
I have seen a Lathe or Mill do that in the Ship yards and brown out the building and the computers.  Smell that motor as it melts down.
Title: Re: random electrical related question
Post by: Art Welter on February 05, 2015, 12:29:09 PM
Yep.  At our downtown arena they rented a really big genset (think 53' semi trailer) and hooked it into the water chillers.  They fire it up to start the chillers and then take it offline.  The reduction in peak billing paid for the genset a couple times over, I'm told.
When we first rented a warehouse with 600 amp three phase power we thought "Great, now we can finally test out our lighting rigs full tilt !"

Then we got the first electric bill with something like a $600 "peak fee" on top, even though the 144 K light system had only been "bumped" for a few seconds. We then made the rule "no more than 6K at one time"...
Title: Re: random electrical related question
Post by: claude cascioli on February 23, 2015, 05:47:37 PM
Just a random question.

Back in the days of yore, How much AC was actually needed on those big fully rigged par can overloaded staged in the 1980's I'm guessing the equivalent of blocks worth of suburban houses. Or a shipyard...

Seems outrageous considering most bar rigs could be fed with 2 15A circus these days.
it all depends on how many cans you had 12 cans 1000 watts each 12,000 watts total divide by 120 volt= 100 amps now how many cans were on at once and how long i seen many melted cables by overload back then most clubs had light built in with proper power and dimmers
Title: Re: random electrical related question
Post by: TrevorMilburn on February 27, 2015, 05:11:57 AM
Just a random question.

Back in the days of yore, How much AC was actually needed on those big fully rigged par can overloaded staged in the 1980's I'm guessing the equivalent of blocks worth of suburban houses. Or a shipyard...

Seems outrageous considering most bar rigs could be fed with 2 15A circus these days.
I had a friend who was backstage at a Van Halen concert at the Rainbow Theatre in London many, many years ago. Evidently they were carrying about 1000 par64 cans and there was no way the house power distro could handle that much power draw. So the only way to get access to almost 'limitless' power was to hook in to the incoming 3 phase mains (415V) before the house distro system. None of the stage or house crew were prepared to risk such a hook up but when substantial money was offered someone volunteered to do the deed and hooked power leads straight onto the incoming power cables. Result - show went ahead and the snow on the pavement (sidewalk) where the power cables came into the theatre miraculously melted.