Classic, Futuristic Lighting

If you thought you saw a Vari-Lite VL5 on the High End Systems booth at LDI 2018, you're not alone.

For the uninitiated, he VL5 was a classic moving yoke color wash fixture from the last millennium (1992, to be exact) and it had a most distinctive look. Instead of a lens on the face of the head, there was this radial tilting dichroic color mixing apparatus punctuated by a small metal cover in the center that made it look like a big pupil or a jet engine. It was the closest thing to Cadillac fins that the lighting industry ever had.

But you didn't see a VL5 at LDI, you saw the retro/futuristic TurboRay, the latest innovation from High End and Richard Belliveau. The fixture takes a fresh approach to a classic idea, updating it with a four-celled RGBW LED engine, gobos, variable frost, and a zoom lens. The effects it produces are unique, and the combination of the very narrow to super wide beam, the digital breakup, and the ability to create a four-color beam emanating from the head create a looks you've never seen. But the real eye-catcher are the tilting radial dichroics. They have been updated with optical edging to creates a sort of light-pipe that enhances the trapezoidal shapes and adds color to the edges of the filters.

I'm looking forward to seeing what Roy Bennett or some other very creative LD will do with them. My guess is that he would put them on a show by the dozens but the emphasis just might be the lights themselves rather than the beams they throw. But we'll have to wait until the Spring to see any of them on any show because they aren't shipping yet. Word is that they will start shipping sometime in the first half of 2019. In the meanwhile, I hope to see you at NAMM in January.

Zzzz....

Did you get enough sleep last night? If you work in live event production, the chances are you did not. Between our busy production schedules and the culture of "the show must go on," too often we are an industry of sleep-deprived individuals doing the best we can to make it to the next day off and hoping to catch up on our much-needed beauty rest.

It's a problem that was a major topic of discussion at the Event Safety Alliance's Safety Summit, which was recently held at Rock Lititz. The problem is that chronic sleep deprivation can lead to serious health problems, reduced cognition, temper tantrums, and, as a result, increased risk of accidents. There's a great Ted Talks video by Claudia Aguirre called "What would happen if you didn't sleep?"

Interestingly enough, in another Ted Talk by Jessica Gamble called "Our natural sleep cycle is nothing like what we do now," she talks about what has been learned from sleep studies. It turns out that when people are allowed to listen to their own body clocks and live without natural light (which allows them to sleep without even knowing what time it is), they tend to sleep from 8PM to midnight, wake for a couple of hours, and then sleep again from about 2AM to sunrise. Does that cycle sound familiar? If you've ever done a concert tour, you might have been lucky enough to catch some shut-eye during the show, typically 8PM to around midnight, load out, then go back to sleep again from 2AM until breakfast. Lucky you.

For the rest of us, it's time we seek solutions to this pervasive problem. There are no easy answers, but solving hard problems is what the live event production industry specializes in.

Event Safety Summit 2018 - Sleep deprivation and its consequences was a major topic of discussion.

Line Loss: Easy as 1, 2, 3

Today, we had a power lab (hands-on workshop) at Dadco Power and Light in Sun Valley, California. This is an annual event hosted by IATSE Local 728 for their members, and the owner of the company, Ron Dahlquist, generously provides space and gear. As part of the workshop, I wanted to demonstrate voltage drop (a.k.a. line loss). What is voltage drop? I'm glad you asked.

Every time you connect a load and turn it on, the supply voltage is applied to the circuit, but some of the voltage is dropped across the wiring, and what's left is applied to the load. The amount of voltage that is dropped across the conductors depends on the amount of current flowing through them and the resistance of the conductors. If the current is too high, or if the conductors are too small or too long, then too much voltage will be dropped and not enough applied to the load. How do you figure out ahead of time if that's the case? You're awfully curious, and I like that.

According to Ohm's law, the voltage that is dropped across the conductors is the current times the resistance of the wire. In the back of the National Electrical Code (NFPA 70), there is a table that gives you the resistance of copper wire based on the length and the gauge. I like to use that to predict voltage drop (sometimes called line loss).

At the workshop we had a setup with a 12kW tungsten lamp connected with 200' of banded feeder cable (#2 AWG). According to Chapter 9, Table 9, the resistance of 1000' of #2 AWG copper wire is 0.19 ohms. Since we had a 200' run, that means we had 400' of copper (200' to the load and 200' back to the supply). And since 400' divided by 1000' is 0.4, we calculated a total resistance of 0.076 ohms (0.19 × 0.4 = 0.076). Since the light operates at 120V, we also calculated a current of about 100 amps (12,000 ÷ 120 = 100). Therefore, we expected to measure a voltage drop of 7.6 volts.

After firing up the genny, we measured the current at the generator and it was 125 volts. Then we measured the current at the load, and it was 118.6. That means we had a voltage drop of 6.4 volts.

Our calculation was pretty close, but we weren't as close as Ron's estimate. Just before we measured the voltage drop, Ron whispered in my ear. "I'll bet the voltage drop is 6 volts," he said. He was closer than we were. How did he know?

Ron later told me that he has a rule of thumb that comes from years of experience. He calls it the 1-2-3 rule. It says that you will get about 1 volt of line loss per 100' of 4/0 AWG cable with 100 amps, 2 volts of line loss per 100' of 2/0 AWG cable with 100 amps, or 3 volts of line loss per 100' of #2 AWG with 100 amps.

The Roman historian Tacitus said, "Experience teaches." Yes, it does, but there is no better combination than experience and training.

Where does the electricity go?

One of the joys of teaching classes and workshops is watching the expressions on people's faces when they suddenly get it. That happened the other day when one of the attendees in a class pulled me aside during a break.

"I've always wondered," he said. "where the electricity goes. I thought it came back through the neutral and went into the ground."

He was pointing to an illustration I had drawn of a typical circuit, and he indicated that he thought the current literally flowed into the earth where it just magically...disappeared maybe?

Of course, that's not what happens at all. The current flows in a loop starting from the supply, then through the circuit, and back to the supply again. There is just enough energy to return the current to the supply, and then it starts over again.

The reason we earth our electrical systems by driving a ground rod (or using one of many other ways to connect the electrical system to the earth) is mainly for lightning protection and for a 0-volt reference, which stabilizes our voltage. If lightning strikes the building or the electrical system, the connection to the earth funnels the energy into the earth so it can be dissipated. But that connection has nothing to do with the normal path for current flow.

How Much Money Should I Ask For?

Every so often I get a couple of phone calls or emails that go something along the lines of...

"How much money should I be making as a (tech, programmer, electrician, lighting designer, fill-in-the-blank)?"

That's probably the hardest question to answer in the history of live event production. Information about what people earn in our industry is hard to come by. A lot of people don't like to disclose that information for whatever reason, and companies discourage employees from discussing it with other employees because if any two employees know what the other is making, chances are that one of them is going to be disappointed, hurt, or upset. This lack of information leaves us all at a disadvantage when we're negotiating compensation. Information is power.

There are companies out there that focus on collecting data about average salaries and compensation based on job titles. The idea is that you should be able to type in your job title or job description and get a good idea of your market value. And knowing what the going rate for your job description is key to making sure you're being fairly compensated.

I once read a blog post by best-selling author Bernard Marr, and he had a great suggestion for negotiating your salary or compensation. It's always uncomfortable when you have to decide how much to ask for a salary or pay rate. So rather than talk about how much you need to live or to support your lifestyle, it's much better to talk about the market rate for someone with your skills.

The problem is that there is very little (if any) data for the live event production industry. If we had a better idea of the average hourly rates, day rates, or salaries of techs, electricians, programmers, and designers based on geographic location, then it would be much easier to negotiate a fair compensation package. Instead, we're pretty much left to our own devices and often time we are negotiating in the dark. If only we had some light!

Shining some light on the subject would be easier if there was a central depository of information that was completely anonymous. Then no one would be self-conscious or fear retribution. But even with such a database, there are no guarantees that people wouldn't try to game the system by reporting higher compensation in hopes of pushing up the curve. What we really need is third party reporting. Until then, here are some ideas that might be helpful:

1. Think win-win. Your compensation is a two-way street. If you want a longterm relationship, then whoever is paying you needs to be fairly compensated in terms of benefits from your endeavors or cash money.

2. Think longterm. Not only do you need to earn enough money to live, but you will some day want to retire, so you should be tucking away about 15% of your income for that purpose.

3. Think overhead. In addition to paying yourself, you'll also need to pay expenses and overhead that could include self-employment taxes, office supplies, utilities (that portion of which is used exclusively for your job), and more.

4. Think about taxes. Uncle Sam (or the equivalent governmental entity if you live outside of the USA) will come calling every year and you have to be prepared to write a check to cover your taxes.

What am I missing?

Stay Ahead of the Storm

A couple of years ago, my daughter and I went to the X-Games in Austin for the third year in a row. We were under flash flood warnings so I was hyper-aware of the weather. The atmosphere was unstable and there were popup showers in the area. As we were watching the Skateboard Street competition, we could see a big bank of black clouds gathering in the distance. I was hoping it would go around us but I was monitoring it closely on my iPhone weather app, WeatherBug. My main concern was lightning. WeatherBug has a lightning app within the app called Spark. It uses real-time lightning data and your GPS, and it tells you how far away the closest lightning strike is to your location. Unfortunately, it didn't work when I needed it most. I knew there was lightning in the not-too-far distance but Spark just gave me a blank screen.

The X-Games is very good about monitoring the weather and making the right call. Just the day before, the entire park was evacuated to our cars while we waited out the weather. So I felt okay about staying to watch Skateboard Street even though I could see the gathering clouds. But when the announcement came over the PA to evacuate the grounds and retreat to our cars, all hell broke loose. In about less than one minute after the announcement, the skies opened up and large drops of rain pelted the scattering crowd. Everyone scrambled to gather their loved ones and their belongings and headed for the exits. Me, my daughter, and her two friends started running for the shelter of my car in the parking lot about half a mile away. Before we could go ten meters, the wind picked up and that's when I really started getting concerned.

I grew up on the Texas coast and I've lived through several hurricanes, so I feel like a have a pretty good grasp of the power of hurricane-force winds. That day at the X-Games, it felt like we experienced close to hurricane-force winds. At that point, my concern shifted from lightning to wind. There were so many tents, cranes, and structures that could be blown over that I kept my head on a swivel, trying to anticipate what would happen next. At the same time, I was trying to keep my eyes glued to my daughter and her two friends, coral them, and guide them to the car without getting lost or hurt. Once I made eye contact with them, we all ran towards the parking lot. About 10 meters into our mad dash, the three of them decided to stop and seek shelter under a small pop-up tent along with about 30 other people. I understand why they did that; large drops of rain were pelting them, soaking them to the skin, and everyone else seemed to be doing it. But I wheeled back around and urged them to keep running for the car. Reluctantly, they did.

We ran another 300 meters into the paddock where they house the EMTs and ambulances. Fortunately they had opened the gates to these normally off-limits premises. We were herded in there with dozens of other people, all of us soaked to the skin. I pulled my cell phone out of my soaking wet pants and pulled up the Sparks app. It finally worked. There was lightning within six miles.

I never felt like our lives were in danger, but I did feel like the situation could have turned as quickly as the rain and wind was unleashed upon us. While we were waiting for the all clear signal, I had time to reflect on what had just happened, and how we could have been better prepared. Lessoned learned:

1. Knowing the weather was unstable going into the event, I should have not waited until the announcement to evacuate; I should have gathered the troops and started moving towards the parking lot when the dark clouds were approaching.
2. By the time the bad weather hits, it's too late to make a plan. I should have prepared the girls for the possibility of evacuating before it started raining and gusting. When the weather hit, it was pandemonium. People were running in every direction and we could easily have been separated. In fact, I witnessed one mother desperately calling out for her child, from whom she had been separated during the event. I was torn between wanting to help her and feeling the tugging responsibility to the three girls. Not knowing what the child looked like, I decided that there was nothing I could do at the moment to help here. Later on, I saw her and her child in the paddock.
3. What I remember most vividly is how loud it was. The howling wind makes a surprisingly loud noise, making it almost impossible to give or follow instructions. If I had a do-over I would have told the girls that, in the event that we were separated, we would meet at a designated spot.

230, 231, Whatever It Takes

Question: My understanding is that if you have a 230V, 3-wire device like a motor and you feed it two 120V hots and earth, then it is running at 208V.  Alternatively, you can use a step up transformer and feed it one 230V hot, one neutral, and earth and it is running at a full 230V.  Is there a scenario where this device is fed with two 120V hots and it is running at 240V? For example, if both 120V taps come off the same phase leg (or if they come off different phase legs?) Or is 120V + 120V and earth always 208V?

Answer: Yeah, it can be confusing. Here’s the lowdown. Most likely your 230V device is European; otherwise, it would be a 208V device or a 240V device. In Europe, the hot-to-neutral voltage is 230V (except in the UK where it is actually closer to 240V, but they still call it “230V.”) So the three wires on this device are probably one hot, one neutral, and one earth conductor.

In North America (and other parts of the world), if you feed it using two hots from a 3-phase system, it will get 208 volts. 

On the other hand, a lot of homes have “split-phase” service, meaning the phase-to-phase voltage is 240V and the phase-to-neutral voltage is 120V. That’s not a 3-phase system, but it allows you to use 120V for everything in your house except the washer and dryer, which are probably 240V devices. Also, some venues have “delta power,” which means the phase-to-phase voltage is 240V, but one of the windings in the transformer has a center-tap, which allows you to pick off 120V from phase to neutral. Delta power is more common in industrial parks where they have light manufacturing because they use the 240V for heavy machinery like drill presses, punching machines, CAD/CAM, etc., but they also have 120V for their computers and microwaves. You can identify delta power by the orange marking on the “high” leg, and it’s important to know that the voltage from the orange leg to neutral in delta power is 208V. That’s the only time you’ll find 208V from phase to neutral in North America, which is why is has to be identified by orange as a warning to users. 

Lastly, most 3-phase generators can operate in “single-phase zig-zag” mode, which gives you 120V from phase to neutral and 240V phase to phase. 

So there are a couple of different ways to get 240V in North America but it depends on the service.