I am new to these boards and far from a pro sound engineer so my apologies in advance for the basic nature of my question, or if this topic has been covered in previous threads.
I could use some advice on AC power for a very small setup for an outdoor block party. Four-piece band - two electric guitars, one electric bass and a drum kit. Two JBL 515's for mains and two small Behringer powered floor monitors. Mackie mixer with 6 mic inputs and 2 stereo channels. Hoping to use the PA just for 2 or 3 vocal mics (but may also run an acoustic guitar into the Hi-Z input for some songs instead of a second electric guitar) but would consider miking guitar amps or running bass direct if needed. There probably won't be more than 100-200 people in the "audience" and I'm told we'll be setting up on the street, with heavy-duty extension cords from someone's house providing our AC power.
My main question is - should the extension-cord method be OK for that rig? I have 2 Furman 6-receptacle floor power conditioners and am thinking one of those will plug into the female end of the extension cord running from someone's home. I'll need more than 6 outlets - a total of 10 by my count (one mixer, four powered speakers, three instrument amps and two pedalboards) so either will need to daisy chain one Furman into the other or run 2 extension cords from the house. When I played in bands in high school and college - many years ago - setups like that mostly worked OK but I do remember some occasions in which noise and mikes that would deliver a little shock if you ate them caused problems. I'm slowly dipping my toes back into playing live with other musicians after many years and have not used this equipment outdoors yet.
I'm not looking for pro-quality sound here. Just want to make sure the setup is safe and sounds "good enough" for a few old dudes playing classic and alternative-rock covers in a casual setting.
Again, apologies for the basic nature of the inquiry but I figure this should be an easy one for the members here. Thanks in advance for any thoughts or advice.
I am new to these boards and far from a pro sound engineer so my apologies in advance for the basic nature of my question, or if this topic has been covered in previous threads.
Nate,
Please change your visible name to your actual name and we'll be able to help you. This board requires that everyone use their real name before posting.
Welcome aboard.
Mike Sokol
My main question is - should the extension-cord method be OK for that rig? I have 2 Furman 6-receptacle floor power conditioners and am thinking one of those will plug into the female end of the extension cord running from someone's home. I'll need more than 6 outlets - a total of 10 by my count (one mixer, four powered speakers, three instrument amps and two pedalboards) so either will need to daisy chain one Furman into the other or run 2 extension cords from the house.It's not the number of outlets you need that you should be calculating... as Scott alluded to, you need to factor in the actual power draw for everything. You may be OK on one 20A circuit, or you may require two. Or three.
The well-meaning homeowner who wants to bring you "heavy duty extension cords," -- well, as Dick mentioned, they probably won't be the right type, and could therefore be dangerous.
And, yes, the issues with shocks were from many years ago. Not something I've experienced at all with my current rig. Using tube amps in good condition and recently purchased mixer/powered speakers.
Using the dryer plug is not acceptable. Dryer plug is three wires two phases and a neutral. Without a safety ground.
Now you can take the ground out and connect it to a regular outlet but this is not to the NEC because the safety ground can be disconnected without disconnecting the mains.
Code requires all sub panels (this application is a sub panel) to have four wires of the appropriate size, period, end of conversation.
Do people make other temporary accommodations every day? Of course they do. Is it safe, no? Is it right, no. Does it void your liability coverage, for sure.
... Scott, who said anything about using the dryer plug?? :o
Both range and dryer plugs used to be 3 wire. NEC requires (I think since 2005 or 2008) both to be 4 wire. Age of house/local codes/inspection requirements will determine what is installed.
No doubt, eventually you will start to see 4-wire receptacles with bootleg grounds-just human nature!
Me! Me! I know!!
No one.
There was a range plug mentioned...
In either case, I should be mindful of the total current draw of all devices being used on stage. One quick question regarding that: should I include every stomp box being used by guitarists, or just the requirements of the pedalboard power supplies (pedal power in both cases)? I'd think the latter, but as you can tell I'm not an electricity expert so figure it's worth checking.
I get to say it again learn something new. Never seen a four prong range in anything but commercial. l
Using the dryer plug is not acceptable. Dryer plug is three wires two phases and a neutral. Without a safety ground.
Now you can take the ground out and connect it to a regular outlet but this is not to the NEC because the safety ground can be disconnected without disconnecting the mains.
Code requires all sub panels (this application is a sub panel) to have four wires of the appropriate size, period, end of conversation.
Do people make other temporary accommodations every day? Of course they do. Is it safe, no? Is it right, no. Does it void your liability coverage, for sure.
But I guess in light of the aforementioned factors I'm still wondering whether, if all our equipment uses "grounded" power cords and balanced connections for mics and speakers, the one-or-two-wall-outlets-fed-by-heavy-duty-extension-cords method will truly be unsafe.
Did you already tell us how long of a run this would be from these "home" outlets to the stage? If not, please walk it off and let us know. I typically rent something called Yellow Jacket cable ramps for gigs where the power wires cross paths with pedestrians or cars. Maybe you have a local sound company that will donate some Yellow Jacket rentals for the good of the neighborhood. Or at least they can give you a cheap deal. They're typically 3 ft in length and heavy as all get out, but you can drive a truck over them while protecting any power cables.
Secondly, any extension cord recommendations even from a distro or generator to the stage and speakers will need to include wire gauge, at the very least. Do you already have extension cords? If so, exactly what are they?
For liability, my home insurance agent was able to provide me with a rider for sound gear and liability coverage for my little gigs many years ago. This was a yearly policy and wrapped up into my homeowners liability policy. Essentially, you don't want to be the fall guy if some guy falls (or something like that). My current business liability policy isn't really cheap, but it covers me no matter what sort of gig I'm doing anywhere in the country (USA). But I need a rider if I go out of the country, even to Canada.
Mackie mixer with 6 mic inputs and 2 stereo channels. Hoping to use the PA just for 2 or 3 vocal mics (but may also run an acoustic guitar into the Hi-Z input for some songs instead of a second electric guitar) but would consider miking guitar amps or running bass direct if needed.
Trying to feed a mixer through a hundred feet of unbalanced cable without converting from Hi-Z unbalanced to Low-Z balanced can result in degradation of the sound quality.
I personally don't know what extension cords are contemplated here. My guess is they're the run-of-the-mill orange jobs a homeowner would use to power holiday lights.
100' is no good. Besides dealing with proper cabling, you have a 100' tripping hazard.
I once did a festival gig down in Annapolis where we had to run a snake and power 60' across a parking lot from the stage to my FOH mix position. So we put down a bunch of Yellow Jacket cable ramps and set orange traffic cones every 10 ft or so. Now this was a black and yellow striped ramp with bright orange cones you probably could have seen from space. But even before the concert began and with nobody else in the parking lot, one lady walked right up to the cable ramps, tripped over a traffic cone, and fell flat on her face. She was walking and talking to her friend and never looked down. Ouch! :o
It is interesting to observe how people can trip more readily over cable ramps then they will if you just laid the cable out on the pavement... it's like, "we're doing this for your safety" yet it ends up being more risky? Awkward.
No matter how hard you try to idiot proof something, they're always making better idiots. ::)
and I'm there having to stop people from climbing ON the generator... sheesh. Do I climb on the bumper of your car?!?
It is interesting to observe how people can trip more readily over cable ramps then they will if you just laid the cable out on the pavement... it's like, "we're doing this for your safety" yet it ends up being more risky? Awkward.
Then the AHJ will be all like "that's nice about the cable ramps. Now put up a sign warning people about them. And make sure the sign won't fall over."
If you borrow extension cords-even for short runs to a genny make sure you double check the ground prongs. It seems like they are engineered to have a life expectancy of about 1/10th the power prongs. Unless the cords are like new and well cared for they will be missing.
If you borrow extension cords-even for short runs to a genny make sure you double check the ground prongs. It seems like they are engineered to have a life expectancy of about 1/10th the power prongs. Unless the cords are like new and well cared for they will be missing.
That's Honda EU Inverter series. Don't try to get by with anything else. A "generator" is not a Honda. Even the non-inverter Hondas won't do.
I want to thank everyone again for sharing the great advice and expertise. I think we've come to a resolution - the organizers have a 5500-watt inverter generator. Not sure the brand but I'm thinking that pretty much ensures safe, clean power for us.
Last question, though: The length of my Furman power strips is likely not long enough to run from the genny to where we'll need juice on "stage." I'm guessing we'll want to have the genny not right on top of us so the noise doesn't drown us out. What gauge of extension cord should I be using to run from the generator to my strips?
Thanks!
Thanks. I asked. Good news: it's a Honda 6500iS.
Mike, what do you recommend to identify the Neutral-Ground bonding plug? Is there a standard color for identifying that device? In the absence of a standard, I would probably use orange e-tape and a Sharpie to mark the plug. Mark C.
I'm double-checking with Honda, but I believe this is a floating neutral generator. If that's the case, you'll probably want to make a Neutral-to-Ground bonding plug, then bond the generator's grounding lug to a ground rod.
An Edison Plug end jumper (like the one pictured above) that is rated for no more than 15 Amps clearly does not meet the requirement to “capable of safely carrying the maximum ground-fault current.” And, it is not permanent (I have had Inspectors kick my grounding clamp on hydrants to see if they are secure.)
And while the twist-lock G-N bond would be preferred to the straight blade plug, most of the time that's already being used for distro or RV power. I'm confident that a 1" length of #12 wire on a NEMA 5-15/20 plug would be able to sustain enough ground fault current to trip off the breaker or circuit protector on any of these small generators in the event of a short. But I do like the idea of a little silicon cement as a vibration fix.
I contend that a electrical inspector that wants to can find a reason to shut down anything including a hiker carrying a flashlight.
I believe that for your setup, you'll probably just run in 120-volt mode and maybe pull power from the 30-amp twist-lock for your stage amps and use the 20-amp duplex outlet for backline and mixer power. At least, that's how I would do it if I didn't have a 2 leg distro available that would connect to the 120/240 twist lock receptacle.
In either of these scenarios, the largest fault current could be 27.5A so I like Frank DeWitt’s idea of a 10Awg jumper bridging the ground and neutral of whichever twist-lock receptacle is not in use. Now that we have established a low impedance path via the bond and ground rod for fault current to travel back to the generator’s windings, will it necessarily trip the breaker and clear the fault? Say the extension cord being handled has a nick and the handler comes into contact with the bare copper of one of the current carrying conductors with one hand while holding onto a metal chain link fence post with the other. How much fault current will there be and will it trip the breaker?
If you don’t know how to answer this question I would suggest you use this link - http://www.screenlightandgrip.com/html/481_GFCI_Workshop.html (http://www.screenlightandgrip.com/html/481_GFCI_Workshop.html) - and read the summary of my IA workshop on ground fault protection – the life you save could be your own.
Guy Holt, Gaffer
ScreenLight & Grip
[email protected]
Getting back on topic, ...
No one wants to take a stab at what the fault current will be in the scenario I described above?
It was out on the street behind where we set up. I know later in the thread there was some talk about grounding the genny, but I also remember back to early in the thread when someone — I think it was Mike — said that tons of events have gone off just fine with an ungrounded genny as the power source.
Thanks again to everyone for their thoughts and advice. Much appreciated.