Getting power? 50 Amps?

[JD]

Yea, overheating and fire are what the breakers are for. We are now in a changing climate though... GFIC breakers protect against fire, but also look for shock hazard. So far, I have only seen these pop up in panels where there is a water concern, like feeding outlets on parking lot light poles. I have run into a problem with local power at venues that I call "Where's the GFIC?" Often normal outlets are off and the breakers are on. Then you go on a hunt and seek looking for the one GFIC outlet that those outlets are chained onto!

 

[Chris15]

RCDs by their very design can't help you if you short active neutral, so while electrical codes might say breakers are only there for the wire, in reality, they're not.

Now are you telling me that the norm is not to have your RCDs mounted on the switchboard, rather using the in powerpoint version is normal? Tis the opposite down here. And I'm just beginning to wonder this. When you lot talk about GFCIs, is that exactly what you mean? GFCI = ELCB? ELCB = old. These days we use RCDs that don't need the leakage to be down the Earth wire, which is what you used to need for an ELCB. RCDs run on a core with an active winding, a neutral winding and a trip coil. Get am imbalance between active and neutral and the magnetic fluxes no longer cancel out and the trip coil energises and triggers the relay to cut the power. ELCBs relied on current flow in the earth wire to trip the circuit, which is somewhat less safe. So if your devices are still ELCBs, then you're what 10 years behind the rest of the world...

 

[fredthe]

Now are you telling me that the norm is not to have your RCDs mounted on the switchboard, rather using the in powerpoint version is normal?

In the U.S., Yes.

And I'm just beginning to wonder this. When you lot talk about GFCIs, is that exactly what you mean? GFCI = ELCB? ELCB = old.

No. Our GFCI is the same as your RCD... they trip on a difference between hot and neutral current. They can even be used where there is no ground connection (such as in refits in old houses), though there are special rules, and they must be properly labeled.

 

[len]

Depending on the hotel, convention center, event hall, etc... you have no idea what you are going to get.

Your best bet is, whenever possible, to visit the site WITH your client AND the site manager and electrician before the event. Specify what the electrical availability is, and if doing a tie-in, who is doing it, where they will do it, where the panel will end up, and WHEN they will do it. Get it in writing and have everyone sign off on it. Then make sure that if the specifications aren't met, it's not your fault and you still get paid.

In my experience, the bigger the event, the more that can go wrong. Good communication and verification of details is key.

 

[stantonsound]

Good advice, but not practical. From experience, you can not get a site manager or electrician together for a meeting, and the customers are usually from out of town and most of the meetings are done over the phone or via the internet. The customer really doesn't give a crap about electricity or how you get it done, as long as it gets done. They pay you to handle those things, so they don't have to. The on site person that knows the most is always the hardest to get in touch with. There are things like receptacles on the 55th floor on the observation deck that are fed from a panel on the 22nd floor, which also tie into the flag pole lights on the 4th floor. In general, things that just don't make any sense. And as far as signing anything, it is highly unlikely that you can get them to sign anything. It is a CYA thing for them.

I have worked in the same facilities since they were built in some cases, and at least for the past 6-7 years. Things change and there are new problems that arise. Most of the production companies that I know try to keep notes on the facilities. I can tell you where most of the circuits in the ballrooms are, and which theatres in town have company services and what their capacities are (as well as loading dock notes, names of the house electricians/AV companies, etc...). Trying to make friends with the house techs is essential!

The problem is that most larger spaces like these have a contract with an AV or production company (or have house staff if they are a theatre), and they make up their packages significantly as the "In House" company, usually 35+%. The house gets the extra cut. The customers that are smart will hire outside production and in many cases save $10,000+, but the house people do not like it when outsiders come in. I usually hire them as labor, or will have them run video and I will run sound and light, or something like that. It usually helps. So does swag!

(an example, we bid a job at $7,000 and it was not discounted in any way with the going rate for everything. The house bid was over $11,500.)

The other trick is to plug in everything early and power it to full. If something trips, you want it to do so early. It the electrician goes to lunch, or just disappears, you have time to find him before the show starts. Also, they make the circuit tracers, with the tone finders. These are pretty cool and will help some. The show that we had a few weeks ago, we tripped a breaker (someone mistakenly lamped S4 pars with 750's instead of 575's and we were over). No big deal, but it took 5 hours to get the circuit reset. It was behind a locked door and we could not focus until the felt like resetting the breaker. Their work comes first, you are second.

 

[SHARYNF]

For more detailed information on GFCI and how they work
http://www.codecheck.com/gfci_principal.htm

I agree the whole problem of getting the house electrician back can be a royal pain, this is one of the advantages of having your own distro, making sure that you have your own main breaker in the distro feed from the House Switch, this way if you pop a breaker on a branch or overload your main feed, the solution and restart is under your own control.

Sharyn

 

[stantonsound]

Sharynf....I completely agree. Here is a photo from a recent event. It was in the club level of a professional football stadium. It is daylight so it is a little difficult to see. We had about 40 instruments total, with the ceiling covered with a star gobo and that was the ambient lighting for the room. The nearest distro system was over 500 feet away, so we were limited to the receptacles on hand. We were able to tie into one 60 amp plug where a fryer unit usually plugs in for a concession stand, but that was it. We also had 6 movers, and we lit all of the columns and then stage lighting for the band.

At this venue, they are GREAT to work with and if we had tripped a breaker, they would have had it fixed in a few minutes.

 

[JD]

Good advice, but not practical.

Hummm... I second that one! During the 80s I toured with rock bands. We always sent a technical rider listing what we needed. I don't think a single venue / promoter ever read them. As for contacting... A little hard to do when you are doing a 90 city 90 day stretch! Most of the time I got a blank stare when asking for the house electrician. Some had disconnects, but most of the time we were on our own. Did a tad under 2000 shows in that decade. Most between 80 and 86. Somehow, we pulled them all off. Not sure how.

I live a quieter existence now. I am usually renting to the venue or promoter. Its clearly spelled out in our bill/contract what we need, along with a disclaimer noting that any switch / electrician fees are the sole responsibility of the customer. Still getting blank stares. You can try, but often, be prepared to be on your own.