Post by: Jeff Wheeler on September 26, 2010, 03:26:46 PM
Cue electrical work to install an HVAC unit at the business next door, which unwittingly pays for some of the electricity that supplies this bar, and half the overhead lights, jukebox, neons, and FoH all go off. They go back on later, but hot and neutral are somehow reversed. This after the "electrician" comes over to borrow a VOM (I'm guessing this guy was not a real electrician.)
Unfortunately, I failed to realize this change until it was too late to do anything about it. Lesson learned: always put FoH power cord up with snake, even if it should not be needed.
Post by: Kristian Johnsen on September 26, 2010, 04:11:17 PM
I have a power cord taped to all my snakes. This means FOH power is always coming from the same place as the PA gear.
Post by: Jeff Wheeler on September 26, 2010, 04:40:06 PM
I think I will buy a bigger case for it soon.
Post by: frank kayser on September 26, 2010, 05:15:14 PM
Hope you didn't experience a lot of damage.
Kristian, what size power cord do you tape to your snake?
frank
Post by: Jeff Wheeler on September 26, 2010, 05:22:24 PM
| frank kayser wrote on Sun, 26 September 2010 16:15 |
Hope you didn't experience a lot of damage. |
No damage, but all the vocal mics required windscreens. I was not too pleased as I watched a mic give a bass player a little zap, sent a stagehand to offer him a windscreen, and then the stagehand came back saying the bass player did not want one. After he played a couple songs, the bass player announced through the PA that he changed his mind and wanted a windscreen.
Post by: Rob Spence on September 26, 2010, 06:20:44 PM
| Jeff Wheeler wrote on Sun, 26 September 2010 15:26 |
Lesson learned: always put FoH power cord up with snake, even if it should not be needed. |
It is always needed in my book. Otherwise, how do you know where your ground is referenced?
I run it but mine isn't taped to the snake.
Post by: Jeff Wheeler on September 26, 2010, 06:23:22 PM
I wouldn't even use my own snake there, except theirs is 13x4 these days and I needed more working channels than that.
Post by: John Livings on September 26, 2010, 07:14:55 PM
Not uncommon at all, to have Larger Areas Divided into Smaller Areas, and not separate ALL the Utilities Properly.
Very common in a Strip Mall for Roof Installs to have power Swaps (You Pay for your
Neighbors Air and He pays for yours) Until you figure it out.
It's always good to trace any circuit you will be using back to the Panel, I write it all down and make SURE I have access to the panel during the time you are there.
There is no simple way of knowing if anything else is hooked to the circuit you want to use if it is not drawing current during your test, You need a back-up.
Regards, John
Post by: Kristian Johnsen on September 26, 2010, 07:34:25 PM
| frank kayser wrote on Sun, 26 September 2010 23:15 |
. Kristian, what size power cord do you tape to your snake? frank |
Frank.
I'm in Europe so we are at 230v just to be clear. The wire size is 1,5mm squared and is approved for up to 16 amps. However, my 50meter snakes obviously have 50meters of line cord on them as well, so I'd expect a voltage drop with that wire size over that distance if I were to fully use the 16amps. In reality I suspect I never pass 4 amps average at FOH, so I'm sure it's no sweat.
For the A-rig 50 meter runs I picked a cord with extra thick outer rubber insulation for mechanical reasons. For some of my shorter snakes I just used normal cord, but the same copper thickness.
I'm afraid I'm no good when it comes to wire gauge conversions
Edit: The snake that sees most "A-use" also has a dedicated DMX line taped to it. As long as I was taping anyway...
Post by: Kevin Hoober on September 26, 2010, 08:36:18 PM
| Jeff Wheeler wrote on Sun, 26 September 2010 14:26 |
They go back on later, but hot and neutral are somehow reversed. |
Does not equal:
| Jeff Wheeler wrote on Sun, 26 September 2010 16:22 |
...all the vocal mics required windscreens. I was not too pleased as I watched a mic give a bass player a little zap.... |
I would not expect a hot/neutral swap to have any affect on your gear, much less, put voltage on pin 1. The only pin of the electrical socket that should be connected to the mic shell should be the ground(ing) pin (via pin 1 in the XLR).
I'm not suggesting that the 'Electrical work' was not to blame for the malfunction--just that a Hot/Neutral swap shouldn't cause the problem you described. Maybe the HVAC guy used tied the neutral to the ground bus (in a panel that wasn't the service entrance) and hence put voltage of the ground bus due to voltage drop in the grounding wire. I would expect other problems/symptoms if your ground wire had suddenly gone to 120V.
Totally agree w/ your takeaway (don't take anything for granted)--just suspect something else was happening other than a hot/neutral swap.
Kevin H.
Post by: Rob Spence on September 26, 2010, 08:45:47 PM
I had advanced the gig in a hotel ballroom and there were a bunch of easily accessed outlets with nice new 20a (5-20r) connections.
When I got there yesterday and went in to meter them, I found that the hotel had installed a distro with about 8 20a circuits right where I needed them. I did meter them and they were wired right.
My quick check these days is with one of those KillaWatt meters with a circuit tester plugged into it. Just plug it in and it tells you if it is wired right and what the voltage is at a glance.
Post by: Jeff Wheeler on September 26, 2010, 08:59:50 PM
| Kevin Hoober wrote on Sun, 26 September 2010 19:36 |
just suspect something else was happening other than a hot/neutral swap. |
You are probably right. I wasn't able to discover what exactly was done by the "electrician." This is a venue that had an electrical fire a couple years ago (imagine that) and the fire marshal just demanded more lighted exit signs and let them re-open as soon as they got the materials to replace the shit that burned up, which was the entire service panel. I'm told an ABC extinguisher was of no use and the fire did not stop burning until the power company arrived (very quickly) to disconnect the building from the pole! I think he must like fighting fires more than preventing them.
Post by: Kevin Hoober on September 26, 2010, 09:03:40 PM
Post by: frank kayser on September 27, 2010, 10:50:16 AM
| Kristian Johnsen wrote on Sun, 26 September 2010 19:34 | ||
Frank. I'm in Europe so we are at 230v just to be clear. The wire size is 1,5mm squared and is approved for up to 16 amps. However, my 50meter snakes obviously have 50meters of line cord on them as well, so I'd expect a voltage drop with that wire size over that distance if I were to fully use the 16amps. In reality I suspect I never pass 4 amps average at FOH, so I'm sure it's no sweat. For the A-rig 50 meter runs I picked a cord with extra thick outer rubber insulation for mechanical reasons. For some of my shorter snakes I just used normal cord, but the same copper thickness. I'm afraid I'm no good when it comes to wire gauge conversions Edit: The snake that sees most "A-use" also has a dedicated DMX line taped to it. As long as I was taping anyway... |
Thanks, Kristian!
You supplied me with what I need: volts, amps, and metric wire size - I can do the necessary reading to do the conversion. Admittedly, I was a bit surprised at the current draw you were planning for at FOH - I guess if there are some amps back there...
I'll keep the DMX hint in the back pocket until I need it.
Thanks
frank
Post by: Tim McCulloch on September 27, 2010, 10:52:35 AM
| frank kayser wrote on Mon, 27 September 2010 09:50 | ||||
Thanks, Kristian! You supplied me with what I need: volts, amps, and metric wire size - I can do the necessary reading to do the conversion. Admittedly, I was a bit surprised at the current draw you were planning for at FOH - I guess if there are some amps back there... I'll keep the DMX hint in the back pocket until I need it. Thanks frank |
Another "while you're taping the loom" suggestion: CAT5e. You'll need it eventually. Trust me.
Have fun, good luck.
Tim Mc
Post by: frank kayser on September 27, 2010, 11:28:45 AM
| Tim McCulloch wrote on Mon, 27 September 2010 10:52 |
Another "while you're taping the loom" suggestion: CAT5e. You'll need it eventually. Trust me. Have fun, good luck. Tim Mc |
Yup. Wouldn't have thought of that even though now I'm running wireless to my XTI rack via Ethernet-to-USB converter. I could see more and more uses for Ethernet as new equipment comes along.
I do wonder about using one pair of a normal snake to pass Ethernet - mic cable is twisted pair, after all. One pair would probably be fine for 10 Base T, and maybe 100 Base T - though I wouldn't bet on the latter - cable twisting and termination really starts making a difference at those speeds. Forget trying to cheat with gigabit.
I doubt the data rate on the amps is all that much (XTI or ITech). I'd guess 10 mbps should be plenty for FOH to stage in an analog world - and 10 Base T runs on cat3 or cat4 cable.
frank
Post by: Jeff Wheeler on September 27, 2010, 12:55:09 PM
The old Cisco Long Reach Ethernet is also excellent. I have seen a demonstration of LRE being used to transport Ethernet over a rusty barbed wire fence.
Post by: Silas Pradetto on September 27, 2010, 01:03:47 PM
| Jeff Wheeler wrote on Mon, 27 September 2010 12:55 |
My understanding is that the latest DSL technology is probably the best way to move Ethernet frames over questionable copper infrastructure, such as audio snake channels (and connectors) not designed for Ethernet. I do not know what small, one-port DSLAM-type units are available, but if I was a large provider with a need to build ad-hoc networks that exceeded what I could do with wireless Ethernet gear, I am fairly sure I would try this approach. The old Cisco Long Reach Ethernet is also excellent. I have seen a demonstration of LRE being used to transport Ethernet over a rusty barbed wire fence. |
So the less-than-ten-cents-a-foot cat5 is too good for you? (edit, should have replied to Frank)
Or even the 50-cents-a-foot Dcat5?
Why make it more difficult than it needs to be? Especially if you're running anything high-bandwidth over the copper (like MADI or Dante), you're going to need every bit of the real cat5 spec to be reliable.
I even used to see dropped frames with my ProCo Dcat5 (only rated full cat5 spec to 200 feet) and the RSS M-400, which uses ALL of the bandwidth available on a 100Mbps network.
Edit2: Next show I do, I'll take a screenshot of how many frames and bytes have run over the network, just monitoring some Itechs. It is a TON of data, more than I use just browsing the internet for a couple days.
Post by: Jeff Wheeler on September 27, 2010, 01:20:01 PM
Post by: Silas Pradetto on September 27, 2010, 01:24:44 PM
| Jeff Wheeler wrote on Mon, 27 September 2010 13:20 |
I just mentioned it since someone suggested using ordinary Ethernet over audio snake cable. I don't know if that would work, but there are other technologies that definitely will, with less bandwidth as you point out. I would like to have a set of DSL bridges for this in the future, but I don't know what devices are cost-effective for the "head end." |
I think, if the network is only going to be used for control signal, a simple wireless N network is going to me more than enough. Why battle running digital data over a snake that is not meant for it when you can get 300M easily 500 feet line of sight with a couple wireless N routers set up in bridge mode?
I figure if someone needs to transport digital audio over cat5, they'll run actual cat5. No one would take shortcuts with a digital snake.
I used to run cat5 to FOH for control in addition to cat5 for the digital snake. Since I switched to wireless N, I never even bother anymore. I can walk down the street at most events till I'm way out of sight and still have wireless signal.
Post by: Jeff Wheeler on September 27, 2010, 01:33:51 PM
| Silas Pradetto wrote on Mon, 27 September 2010 12:24 |
Why battle running digital data over a snake that is not meant for it when you can get 300M easily 500 feet line of sight with a couple wireless N routers set up in bridge mode? |
I have a friend who does the on-site network for a conference of technology people, and uses all available channels for wireless access points in some coverage areas. If you had the misfortune of providing for his event, you would find that your 802.11n would be competing with his devices for RF. I imagine this could also be true in hotels that supply wireless Internet for their guests.
Post by: Silas Pradetto on September 27, 2010, 01:38:37 PM
| Jeff Wheeler wrote on Mon, 27 September 2010 13:33 | ||
I have a friend who does the on-site network for a conference of technology people, and uses all available channels for wireless access points in some coverage areas. If you had the misfortune of providing for his event, you would find that your 802.11n would be competing with his devices for RF. I imagine this could also be true in hotels that supply wireless Internet for their guests. |
You can easily have multiple access points running on the same channel. Especially wireless N, which uses MIMO over a broader bandwidth than the former wireless G.
You'll find that almost no hotels or businesses are using wireless N yet, so there is still LOTS of room available.
But I've never had a problem sharing a channel with another wireless network; I have a WiFi scanner on my phone that I always use to check things out.
Post by: frank kayser on September 27, 2010, 01:44:37 PM
I have a box of cat5 in the garage left over from wiring the house - so, no, it isn't too good for me.
Maybe cat5e of cat6 is too good for me, though 
The snake channel just popped into my head - just wondering aloud along the lines of - sure would be cool if someone started building in one or two runs of cat5e or cat6 in the snake bundle, as more and more comm to/from the stage will be used. There are Neutrik "D" size ethernet connectors - perfect for the stage box - that led to "what about a spare return"?
It wasn't all that long ago that ethernet over twisted pair was new and quite controversial. Thick ehernet was the standard, giving way to a bit of thin ethernet. Hell, I've seen ethernet run over flat phone wire before. Will a snake channel be optimal? Hell no, but again, at 10mbps, it ain't all that picky.
Of course, now I'm going to have to try it - see how fast it will sync, and see how many retransmission errors it generates. All in the name of good, clean fun.
frank
Post by: frank kayser on September 27, 2010, 01:58:56 PM
Probably ought to go back to FOH Power SNAFUS.
Post by: Tim McCulloch on September 27, 2010, 03:16:04 PM
| frank kayser wrote on Mon, 27 September 2010 12:58 |
Sorry, all - I dragged this thread WAY off topic. Probably ought to go back to FOH Power SNAFUS. |
The take-away lesson in both the FOH electrical and data transmission discussion is: If you can possibly put these things under your complete and sole control, you will be better off. No surprises, no "gotcha!"
Have fun, good luck.
Tim Mc
Post by: Kristian Johnsen on September 27, 2010, 04:26:35 PM
| frank kayser wrote on Mon, 27 September 2010 16:50 | ||||
Thanks, Kristian! You supplied me with what I need: volts, amps, and metric wire size - I can do the necessary reading to do the conversion. Admittedly, I was a bit surprised at the current draw you were planning for at FOH - I guess if there are some amps back there... I'll keep the DMX hint in the back pocket until I need it. Thanks frank |
Frank.
Glad to help!
Admittedly, 4amps@230v=approx 1kW and sounds a lot, but as soon as you get a delay speaker, decorative lamp or big screen projector back there things do add up. Plus, if the gig demands two sizeable analog mixers, those could rack up some watts, too - some of those PSUs look like a power amp for a reason!
Anyway, although I in theory could legally run the full 16 amps, I'd feel that to be a stretch, but 4 amps feels totally fine.
Tim's suggestion about cat5 is an excellent one, btw
Post by: devin Basile on September 27, 2010, 05:27:17 PM
thanks d
Post by: Simon Ryder on September 27, 2010, 05:37:05 PM
Post by: Bill May on September 28, 2010, 01:07:28 AM
I'm still new to all of this-
Bill
Post by: Jeff Wheeler on September 28, 2010, 03:32:24 AM
Post by: Bill May on September 28, 2010, 04:00:03 AM
Thanks-
Bill
Post by: Tim McCulloch on September 28, 2010, 10:55:05 AM
I taped a run of 14/3 to my FOH snake 28 years ago and never looked back and never had an induction problem, either.
Today we tape our 8/5 FOH AC lines to the drive snakes rather than the input snake as current demands are higher and the noise accumulation across 48+ inputs *might* be an issue. I can't recall it ever happening, though. The input snake and drive snake are usually next to or on top of each other and we've never had a problem.
I'd be hesitant to run mic snakes next to the 4/0 feeder the lampies are using, however.
Have fun, good luck.
Tim Mc
Post by: frank kayser on September 28, 2010, 08:16:20 PM
NOT one of my original ideas - got it here from another Labster...
How my version works:
I have one of my old, discarded routers - any one will do.
The key is the TCPIP to USB converter -
I use a 4-port Keyspan US 4A - unfortunately it is discontinued
http://www.tripplite.com/en/products/Discontinued-Products.c fm?MDLID=3913
There is a new 2-port model out...
Also, a couple folks here use the Belkin USB server
http://www.belkin.com/networkusbhub/
A note: Neither of these provide a bulletproof link to the amps - but it is workable.
I just got a Netgear WNR3500L - with built in USB for storage devices - we'll see... It has the advantage of being able to load an alternate Linux OS that has enhanced USB support - Who knows.
Post by: Gary Phillips on September 29, 2010, 11:19:27 AM
gp
Post by: Silas Pradetto on September 29, 2010, 11:32:09 AM
| Gary Phillips wrote on Wed, 29 September 2010 11:19 |
I've got a D-Link DIR655 that has a USB port and that runs the ITechs just fine. The remote computer sees the amps on the USB port just fine, but System Architect doesn't. I am presently awaiting word from Crown tech support on this issue. gp |
What? Itechs don't have USB for HiQnet connectivity. They have Ethernet. Nothing USB is needed. If you're talking about XTis, then it makes sense. I wouldn't ask Crown support questions about something that has nothing to do with their amps. They're intended to plug directly into a computer, nothing else. I'm not calling Allen & Heath to complain about my amplifiers...
I've tried using XTis with a USB to Ethernet box with the host software on the computer, it works. Sometimes. Other times it doesn't. And if it does work, the connection freezes and drops constantly. I'd rather put a computer at the amp rack and use remote desktop on it. Or in my case, I just set and forgot all the amps.
Post by: Gary Phillips on September 29, 2010, 08:51:14 PM
Thanks for the insight!
Gary.
Post by: Jeff Hague on September 29, 2010, 09:58:04 PM
| Jeff Wheeler wrote on Sun, 26 September 2010 15:26 |
even if it should not be needed. |
It is ALWAYS needed...