Post by: Nick Andrews on May 24, 2017, 11:27:33 AM
I am going to be doing a small weekly outdoor event starting next week through the early fall. This is not going to be very high spl , and the gear i'm using is pretty efficient. In fact I normally run it off of 2 circuits without an issue.
System is
rcf nxl24a x 2
rcf 8004as x 2
rcf nx15sma x 4
rcf nx12sma x 2
plus a small mixer rack , either x32rack or m32r with a few wireless mics.
plus power will be needed for the bands equipment (1 guitar amp, 1 bass amp, keyboards, so on)
The event space is under a building overhang, and is pretty well protected from the elements in case of rain but it is still technically outdoors.
There is only 1) 20 amp circuit available where the performance will be, I will need to run feeder to a breaker panel where the building engineer said they could tie us in. This approx 200 feet away.
I have in my inventory a amp shop distro, and approx 250 feet of 6/4 soow feeder with CS twist connectors.
My question to you is, what is the correct way to do this?
Many thanks in advance!
Post by: David Sturzenbecher on May 24, 2017, 12:06:40 PM
Perhaps you could be a little more specific with your question.
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Post by: Stephen Swaffer on May 24, 2017, 12:40:23 PM
Post by: Jonathan Johnson on May 24, 2017, 12:45:00 PM
Have the venue hire an electrician to install the appropriate CS receptacle so you can plug your distro in, would be the ideal way-or the Honda inverter is not a bad idea either.
This is ideal. In the long run, it will be cheaper than having the building engineer (or an electrician) tie you in & out 15 times over the course of the summer.
Tie-ins are fine for one-off events, but for a repeating event, having a cord-and-plug connection is preferable.
Post by: Mark Cadwallader on May 24, 2017, 12:46:49 PM
Post by: Tim Hite on May 24, 2017, 01:35:04 PM
The voltage drop over 200' of 6/4 awg cable is pretty significant, IIRC.
Even pulling 30A per leg the drop will only be 5 volts or 4.7% less if he's pulling lower current. Plenty of power, in this case.
Post by: g'bye, Dick Rees on May 24, 2017, 02:13:58 PM
This should be a no-brainer.
Post by: Nick Andrews on May 24, 2017, 02:14:54 PM
Even pulling 30A per leg the drop will only be 5 volts or 4.7% less if he's pulling lower current. Plenty of power, in this case.
Thank you for the Info and replies everyone. I guess to be more specific , is running 6/4 tied into the panel by the building engineer with a cs connector to my distro safe/ legal and ok to do by code ?
Client was not thrilled about having to use a generator.... I would like to own one though , although it would change my logistics a bit ( would need to bring my larger truck)
Post by: Tim Hite on May 24, 2017, 04:33:18 PM
Thank you for the Info and replies everyone. I guess to be more specific , is running 6/4 tied into the panel by the building engineer with a cs connector to my distro safe/ legal and ok to do by code ?
. . .
The answer is "It depends"
We don't know what state you're in or what local code allows. This it why it's recommended to get an electrical contractor involved and just go ahead and install a permanent CS50 plug at the panel or wherever it's convenient.
In the valley I'm in, the parks & rec people have already done this to accommodate these types of event. It also allows them to run vendor booths and such off spider boxes or whatever else they'd like to run whenever they want to, with no additional electrical work having to take place.
Post by: Nick Andrews on May 24, 2017, 05:06:14 PM
The event is in Ny city, I am based out of NJ. Unfortunately they do not want to install anything permanent this year. I can however leave the feeder there and just pull it out the day of the event.
Post by: Chris Hindle on May 24, 2017, 08:57:28 PM
Hi,
The event is in Ny city, I am based out of NJ. Unfortunately they do not want to install anything permanent this year. I can however leave the feeder there and just pull it out the day of the event.
BAD idea.
You can't (shouldn't) leave an energized chunk of wire lying around. It MUST be capped, and out of reach of the public. For it's entire length. Local laws MAY be quite a bit more strict .....
Chris.
Post by: Nick Andrews on May 24, 2017, 09:27:16 PM
BAD idea.
You can't (shouldn't) leave an energized chunk of wire lying around. It MUST be capped, and out of reach of the public. For it's entire length. Local laws MAY be quite a bit more strict .....
Chris.
Hi Chris ,
Yes it would be put away and breakers turned off of course.
Post by: Stephen Swaffer on May 24, 2017, 10:45:23 PM
FWIW, I'm doing a similar sized setup for a church event in a few days. I have the cable, and am qualified to do my own tie-ins,and am well aquainted with the local inspector. I'm planning on using an inverter genny-mainly becasue dragging 250' of SO around isn't as much fun as it used to be ;) .
Post by: Nick Andrews on May 25, 2017, 12:27:04 AM
I'm a licensed electrical contractor. Installing the proper CS receptacle next to the panel should cost about the cost of the receptacle more than doing a tie in. Why not install it and be done? The tie-in should be done by an electrician with the proper gear (arc-flash as need if energized, etc.). A permanent receptacle is less problematic with code than leaving SO "installed" since it is only suitable for temporary use-typically less than 30 days.
FWIW, I'm doing a similar sized setup for a church event in a few days. I have the cable, and am qualified to do my own tie-ins,and am well aquainted with the local inspector. I'm planning on using an inverter genny-mainly becasue dragging 250' of SO around isn't as much fun as it used to be ;) .
Thanks for the reply , very much appreciated ! Unfortunately the client was not into the idea of a generator ... I know .... ;) And for me bringing a generator would make things more difficult logistically as I'd need to bring my larger vehicle to fit everything. I am going to tell them they need to install a cs connector at the panel, I feel more comfortable with this.
..
If I needed to extend the the cable , voltage drop issues aside for a moment , is adding additional feeder length with additional 6/4 with cs connectors a code issue ?
Post by: Rob Spence on May 25, 2017, 12:31:45 AM
Thanks for the reply , very much appreciated ! Unfortunately the client was not into the idea of a generator ... I know .... ;) And for me bringing a generator would make things more difficult logistically as I'd need to bring my larger vehicle to fit everything. I am going to tell them they need to install a cs connector at the panel, I feel more comfortable with this.
..
If I needed to extend the the cable , voltage drop issues aside for a moment , is adding additional feeder length with additional 6/4 with cs connectors a code issue ?
Well, the AHJ is the definitive source but the NEC does have something to say about how many connections are permitted in a feeder. I don't remember the detail though.
I do gigs where we have a 100' and a 50' to reach though I have never (yet) seen an inspector in 5 years.
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Post by: Mark Cadwallader on May 25, 2017, 01:06:53 AM
Post by: Jonathan Johnson on May 25, 2017, 02:04:54 AM
The event is in Ny city, I am based out of NJ. Unfortunately they do not want to install anything permanent this year. I can however leave the feeder there and just pull it out the day of the event.
Why are they balking at something permanent? If it's because they're a public agency and this would be considered a "capital expense" that they haven't budgeted for this year, that's kind of understandable (politics... not really understandable, but I understand in a meta sort of way). Many public agencies can spend money on repairs, but they cannot do capital projects outside of the normal budget process which happens only once a year and then is set in stone. Otherwise, they'd have to declare an "emergency," and this would cause auditors to raise their eyebrows if THIS was an "emergency."
So here's how you work it: YOU pay for the install and adjust your fees to the venue accordingly (or just eat it as "the cost of doing business"). The venue may be willing to do it this way, because then it doesn't show up as a capital expense but as part of an already budgeted item: your services for the recurring event.
Post by: Cailen Waddell on May 25, 2017, 08:01:02 AM
Why are they balking at something permanent? If it's because they're a public agency and this would be considered a "capital expense" that they haven't budgeted for this year, that's kind of understandable (politics... not really understandable, but I understand in a meta sort of way). Many public agencies can spend money on repairs, but they cannot do capital projects outside of the normal budget process which happens only once a year and then is set in stone. Otherwise, they'd have to declare an "emergency," and this would cause auditors to raise their eyebrows if THIS was an "emergency."
So here's how you work it: YOU pay for the install and adjust your fees to the venue accordingly (or just eat it as "the cost of doing business"). The venue may be willing to do it this way, because then it doesn't show up as a capital expense but as part of an already budgeted item: your services for the recurring event.
I work for a municipality and this is spot on advice. While we have forward thinking management, not everyone is so lucky. Other possibilities i or may not of encountered:
if they install an outlet, they would have to pull a permit and pay those fees and attract that attention or an inspector may become aware of other work that the AHJ didn't know about.
The department might have the budget but the project may not have supplies money just contracted services money.
The electrician is friends with someone in the department and really needs the overtime $
There isn't enough power and the person who made that decision during construction could be made to look bad if any upgrades were done proving that they were wrong
The generator is being avoided because there is clear departmental policy on generator use that would require more resources but the tie in does not.
Yeah...
So try to find out what's really going on - make friends - and help everyone achieve their goal.
We just completed a park and streetscape project where we installed 15 50a and 8 L14-30's and a metric shit ton of 20a 5-20 (Edison) around the park and street to accommodate food trucks and stages. Our mobile system (a quite respectable Danley system with digital consoles, with 2 dozen LED pars, and power for backline) can easily run on a 50a or 2 L14-30... we are also in the midst of installing shielded cat5E lines so FOH positions don't require cable runs. And all of this is to say - that when you start considering the size cable ramp needed for ADA compliant crossing of some 6/4 and the time and labor to install, more outlets start to become cheaper. Keep in mind that these agencies are required to be ADA compliant even in temporary events.
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Post by: Jonathan Johnson on May 25, 2017, 01:17:53 PM
Why are they balking at something permanent? If it's because they're a public agency and this would be considered a "capital expense" that they haven't budgeted for this year, that's kind of understandable (politics... not really understandable, but I understand in a meta sort of way). Many public agencies can spend money on repairs, but they cannot do capital projects outside of the normal budget process which happens only once a year and then is set in stone. Otherwise, they'd have to declare an "emergency," and this would cause auditors to raise their eyebrows if THIS was an "emergency."
So here's how you work it: YOU pay for the install and adjust your fees to the venue accordingly (or just eat it as "the cost of doing business"). The venue may be willing to do it this way, because then it doesn't show up as a capital expense but as part of an already budgeted item: your services for the recurring event.
P.S. -- somebody may be thinking that installing a permanent outlet would be a capital improvement that must be put out to bid, and there's insufficient time to go through that process before things have to roll. But maybe not -- many municipalities have policies that allow small projects to be done without going through the whole bid process.
Post by: Mike Sokol on May 25, 2017, 02:44:15 PM
P.S. -- somebody may be thinking that installing a permanent outlet would be a capital improvement that must be put out to bid, and there's insufficient time to go through that process before things have to roll. But maybe not -- many municipalities have policies that allow small projects to be done without going through the whole bid process.A few of our regular corporate and municipal gigs can put any kind of service on their department credit card up to a certain dollar amount without any bidding process. But go one penny over the threshold $ number and a whole lotta paperwork starts. So find out what that dollar about is and you might be able to make it happen.
Post by: Guy Holt on May 25, 2017, 05:59:12 PM
The voltage drop over 200' of 6/4 awg cable is pretty significant, IIRC.
Another approach would be to use a small boost step-down transformer at the end of the cable run to compensate for the voltage drop. We use 7.5kVA full power transformer/distros all the time on our modified 7500W Honda EU6500is generators to compensate for the voltage drop caused by the long cable runs to set in motion picture lighting and the voltage drop on the EU6500s under load. Our full power transformer/distros are equipped with three switch selected taps to increase voltage on the secondary by 0, 5, or 10 percent.
Guy Holt, Gaffer
ScreenLight & Grip
Post by: Cailen Waddell on May 25, 2017, 06:02:14 PM
A few of our regular corporate and municipal gigs can put any kind of service on their department credit card up to a certain dollar amount without any bidding process. But go one penny over the threshold $ number and a whole lotta paperwork starts. So find out what that dollar about is and you might be able to make it happen.
Yes. Luckily my bid threshold on construction is into the $100's of thousands. For equipment purchasing I have $90k bid threshold, and 3 quotes below.
Yeah - if you are luckily in your municipality you have an amazing purchasing staff that help you follow the letter of the law
. I am that lucky. Sent from my iPhone using Tapatalk
Post by: Ed Hall on May 25, 2017, 09:58:52 PM
Another approach would be to use a small boost step-down transformer at the end of the cable run to compensate for the voltage drop. We use 7.5kVA full power transformer/distros all the time on our modified 7500W Honda EU6500is generators to compensate for the voltage drop caused by the long cable runs to set in motion picture lighting and the voltage drop on the EU6500s under load. Our full power transformer/distros are equipped with three switch selected taps to increase voltage on the secondary by 0, 5, or 10 percent.
Guy Holt, Gaffer
ScreenLight & Grip
When using the boost setting on the transformer to compensate for the voltage drop, I'm assuming you get a reduction in current when boosting the voltage?
Post by: Mike Sokol on May 26, 2017, 07:15:28 AM
When using the boost setting on the transformer to compensate for the voltage drop, I'm assuming you get a reduction in current when boosting the voltage?
While voltage boost taps on transformers are useful for constant loads such as lighting, they're of limited value with typical audio loads that have a huge crest factor. That being said, if you could do tricks like step up the voltage to 480 volts on the feeder side then step it back down to 240/120 volts on the load side, you would reduce the voltage drop on the load side significantly. So yes, you get a reduction in the current required in the long feeder run, and that's what reduces the voltage drop. But this is a bit of a trick question with switching power supplies in modern pro-sound gear because they're not linear loads. You still have to consider the load's power factor and crest factor to predict total voltage drop in the wiring.
Post by: Guy Holt on May 26, 2017, 08:57:45 PM
So yes, you get a reduction in the current required in the long feeder run, and that's what reduces the voltage drop. But this is a bit of a trick question with switching power supplies in modern pro-sound gear because they're not linear loads. You still have to consider the load's power factor and crest factor to predict total voltage drop in the wiring.
Every time you use house power, you operate the switching power supplies of your modern pro-sound gear on a transformer - usually a 480/277 to 208/120 Delta--to-Wye utility transformer. While there are legitimate concerns to operating non-linear loads that will draw harmonic currents on a transformer (excessive heat generation being the primary), a step-down transformer will not distort the voltage waveform. In fact, because of their low impedance, you will get a cleaner voltage waveform on a step-down transformer operating on utility power than you will get from a generator - even the Honda Inverter generators. In addition to the voltage flat topping generated when the harmonics drawn by a non-linear load encounter the relatively higher impedance of the Honda Inverter generators, the Hondas will also drop up to 10V under load. The inverters drop voltage under load because they must use a droop voltage regulation because its permanent magnets can't be regulated by an excitation current as is the case with the electro-magnetics of an AVR system. Without a doubt, a step-down transformer operating on utility power will provide a higher quality of power, more stable and less distorted, than that generated by an inverter generator. Add the reduced current draw and subsequent voltage drop, Mike mentioned, and you can see that there are real benefits to using a small step-down transformer with boost taps - which is why we use them with our Honda generators. With proper sizing and design (K Factor Rating) to reduce heat generation, a step-down transformer will always supply better quality power with non-linear loads than a generator, which is the difference between hard and soft power. For more details on how the relatively high impedance of portable generators can lead to severe voltage distortion when powering non-linear loads, see a three part series on production power on a budget I just completed for Protocol Magazine (available at http://www.screenlightandgrip.com/html/hd_plug-n-play_pkg.html (http://www.screenlightandgrip.com/html/hd_plug-n-play_pkg.html).)
Guy Holt, Gaffer
ScreenLight & Grip
Post by: eric lenasbunt on May 26, 2017, 09:42:02 PM
Plus then you don't need to leave $600+ of feeder in a room for months at a time.
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Post by: Stephen Swaffer on May 26, 2017, 11:36:42 PM
Post by: Mike Sokol on May 27, 2017, 07:37:23 AM
Mike's reference on the transformer is primarily directed at the crest factor in audio-not running on a transformer per se.
Interestingly, the Furman M-8X AR is actually a set of buck/boost transformers with Triac switching, so it will automatically ratchet the AC voltage up or down to get it within a few volts of the desired level. Of course, it can only change the taps on the zero crossover of the line frequency, so it's not an actual regulator. But for brownout situations it could be useful.
Post by: Stephen Swaffer on May 27, 2017, 01:30:17 PM
Post by: Mike Sokol on May 27, 2017, 03:03:31 PM
I knew there were "active" buck-boost devices-didn't know the manufacturers/models. Do they respond quick enough to deal with a few cycle brown out? I would be curious how fast they react.
I've never played with one, but from what I remember these are Triac switched taps and should respond with one line cycle.
Post by: Mike Caldwell on May 28, 2017, 11:41:09 AM
One thing that would be big cost to adding a 50 amp connection in the area of the stage if by chance the building does not already have a proper power service in it.