Sunday, December 30, 2018

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.

Sunday, December 9, 2018

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.

Sunday, September 9, 2018

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.

Sunday, July 22, 2018

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.

Monday, June 25, 2018

Help! I Can't Math

by Richard Cadena

Don't tell me that you are just aren’t good at math. I won’t buy into that. On the other hand, if you say that you’re not interested in investing the time and effort to polish your math skills, okay, I get it. Math is not for everyone. But unless you have a learning deficiency like dyslexia, you can get good at math if you’re willing to invest the time and energy. Here’s how.

If you really want to understand your craft as an electrician or technician, then you need some decent math skills. The math is not hard if you practice it. Ohm’s law and the power formulas are just basic algebra. If you break it down into small steps, it’s really simple.

1. What is the question? That may seem like a trivial step, but it’s so important to identify the unknown variable. Write it down and make sure you know the units of measure. For example, if you’re trying to figure out the current draw for a particular fixture, then the unknown variable is the current I, and its units of measure are amps. The reason you should know the units of measure is because that sometimes can give you a hint about how to solve the problem. If, for example, the unknown variable is speed, its unit of measure is miles per hour. You can literally solve the problem by dividing the number of miles traveled by the number of hours it took.
2. What do we know? Identify the knowns or givens by writing down everything we know or are given. For example, if we’re trying to figure out the current draw for a particular fixture, we can look up the specs online and write down what we’re given, which is usually the voltage and the power in watts. Sometimes the specs include the power factor too.
3. Which formula should we use? Write down the formula or formulas for solving the problem. In our previous example (solving for the current draw), we will write down the power formula, but we need to know whether to use the single-phase power formula or the 3-phase power formula. If we’re trying to calculate the current draw for a single fixture, we’ll use the single-phase formula, but if we’re calculating the current draw for several fixtures in a 3-phase system, we’ll use the 3-phase formula.
4. Calculate the answer. Be careful to enter the right values for the knowns.
5. Evaluate your answer. Just take a look at the answer and ask yourself if it makes sense. For example, if you’re trying to figure out the current draw of a 2000-watt fixture at 208V and you get an answer of 961 amps or 0.961 amps, you should immediately suspect you made an error.
6. Double check your work.

Once you practice these steps and get really good at them, they become second nature to you and then you no longer have to think about them, they just happen like the moon follows the sun.

Monday, May 7, 2018

Gimme Three Steps (Toward Success)

I grew up with a friend who made a fortune twice. And unlike other people who have done this, he didn't go broke after his first fortune and then earn another fortune. Instead, he started a successful business, sold it, and after a time he became bored doing not much of anything, so he started another very successful company. I was thinking about him this morning because I remembered something he shared with me about himself.

When I went to visit him in California after he started his second business, Blaze Pizza, he took me to his first restaurant in the chain. While we were sampling the food and service, I complimented him on his success.

"I'm really proud of you," I said. "You've worked hard to make yourself a success."

"Actually," he corrected me, "I don't like to work hard at all." He told me that he takes a very leisurely approach to business and spends very little time in his office.

That goes completely counter to everything I thought I knew about success, leaving me to wonder what really is the combination to unlock it. I don't claim to know all of the digits, but I think I have at least three of them.

1. Great ideas are a dime a dozen. Sure, my friend had at least two great ideas. The first was triggered by a childhood memory. When we were in grade school, one of the kids in our class used to tease him about his last name. He called him Wetzel the Pretzel. Years later, when he was searching for ideas to start a franchise, he remembered that and so he started the Wetzel Pretzel chain. But clearly, a great idea is not the only requirement for financial success or most people I know would be fabulously wealthy. I once had a friend who claimed to have come up with the idea of using a vacuum cleaner hose to drive a motor with a blade that you could use to cut your hair. Only later was the Flowbee vacuum cleaner attachment for cutting hair patented. But it wasn't my buddy who patented it and reaped the financial benefits. Clearly there's more to financial success than just having a great idea. You have to take action.

2. Risk has rewards. Once my grade school friend had an idea for a pretzel franchise, he risked his time and money to start the business. Had he not taken that leap of faith, he would never have made a go of it. But I think there's at least one other ingredient in his recipe for success.

3. Location, location, location. Corpus Christi, Texas is a great place to be from, but it's not the land of financial opportunity. It's a sleepy little seaside city where we grew up, but had his family not left when he was in high school, I doubt he would have succeeded in business. He ended up in the Los Angeles area, which is where he started his first (and second) business(es) and where there is ample opportunity for success in a variety of fields. That's not the only place where his franchises could have succeeded but I'm pretty sure it wouldn't have happened in south Texas.

Whether you want to succeed in the restaurant business or in live event production, I think you need more than a great idea. You need to act on your ideas. It helps to have a tolerance for calculated risk, and be willing to relocate to where the opportunities are. Just ask Rick Wetzel.

Sunday, February 4, 2018

Technology at NAMM 2018

Oscar Wilde once said that when business people get together they talk about art and when artists get together, they talk about business. So what happens when business people and artists get together? They talk about technology. 

Jackson Browne was presented with the Les Paul Innovation Award at the NAMM TEC Awards in January. When he accepted it, he talked about the first tape recorder he ever bought and how they took to the road to record "Running on Empty" in buses and live venues. Then he took the stage with Lee Sklar, Russ Kunkel, Danny Kortchmar, and Craig Doerge (the Section) and played a couple of songs. It was a magical night.

That wasn't the only opportunity to talk or learn about technology. There were a number of newly added sessions having to do with live event production. I couldn't attend them all, as much as I would have loved to, but I either participated in or attended several, including Mike Wood's "LED Technology: From Diode to Light," "Sustainability and Cost Savings in Event Lighting" presented by Mike Wood and myself, "Video Production: LEDs, Fluorescents, Automated Lighting; and Lighting Design for Video Production in the Age of LEDs" presented by Matt Ardine, Kieran Illes, David Kane, Mike Wood, and myself, "Electrical Safety for Stage and Set" presented by Alan Rowe and myself, "Video Production: Power on a Shoestring" presented by Kieran Illes and Alan Rowe, "Console Programming Workflow" presented by myself, "Media Server Programming and Pixel Mapping" presented by Matt Ardine and David Kane, and "Advanced Ethernet Networking" presented by Scott Blair, John Huntington, Kevin Loewen.

My favorite session was "Advanced Ethernet Networking" presented by Scott Blair, John Huntington, Kevin Loewen. These guys are the industry gurus when it comes to networking. Some of the notes I took during the session include...

  • John Huntington said that terminating Cat6A is a "pain in the ass." He said you can use Cat5E for gigabit networks and it works fine.
  • An auto IP is a way of automatically assigning an IP address to a device if it does not receive one from a DHCP server. Scott Blair said that auto IP works with sACN because, as long as the device has IGMP snooping, the IP address doesn't matter. Auto IP addresses are in the range 169.254.x.y.
  • Simple Network Management Protocol (SNMP) is a protocol that allows you to monitor a network. According to the panel, there are several SNMP applications but I think I missed their favorites. I'll be researching that next.
  • John Huntington recommended the Byte Brothers Real World Certifier for testing LAN hardware and cabling. I found this link on his web site with information and specs.
There is still lots to unpack from NAMM but this is a start.