|
Beyond W = VA; #USITT2014
|
 Is modern lighting equipment changing the practice of power distribution? That's the topic of discussion at USITT this year when a panel that includes Andrea Bilkey, Deanna Fitzgerald, Kirk Starks, Steve Terry, and me (Richard Cadena). In preparation for the discussion, I've been giving this some thought over the last....hmmm...seven or eight years, which is about how long I've been an ETCP Recognized Trainer and I've been teaching a 3-day electrics class. What's changed over the last decade in the entertainment industry? Click here to find out. |
 Dear Swami,
During a recent show, I checked the voltage between the neutral and ground at the power distro and found that it was about 50 volts! What is going on? If the ground is truly grounded, and the neutral is bonded to the ground, shouldn't the voltage between them be 0 volts?
signed,
Shocked in Dimmer Beach
Dear Shocked,
Even the well-grounded sometimes float above the earth. In a balanced, 3-phase system with linear (non-harmonics generating) loads, there is no current in the neutral conductor. But with loads like LEDs, fluorescent lamps, electronics ballasts, etc., the harmonics that are produced cause current to flow in the neutral. The combination of current and the resistance of the copper wire causes a voltage drop, which causes a voltage difference between the neutral and the ground, depending on where you're measuring it. The more current there is and the longer the conductor is from the point of measurement and the point the neutral is bonded to the grounding conductor, the higher the voltage difference. So if you have very long runs and very high currents, then expect to read a high voltage.
Sincerely,
Swami Candela of the Third Millennium
To send a question to Swami Candela, click here.
|
Now Available! 2nd Edition of
Electricity for the Entertainment Electrician & Technician
February 17 marks the launch of the revised book about powering live event productions safely and efficiently
About a year ago, I started updating Electricity for the Entertainment Electrician & Technician. Today is the official launch date!
What's new in the book? In a word, lots. Although the fundamentals of electricity don't change, our practices do. So this edition has new information about electrical safety, new types of loads, like LEDs and video displays, and how they affect our power distribution systems. It also has new information about other power sources like portable power generators and batteries.
People often ask me if they should buy the new edition if they already have the old, and to that, I say, "Does electricity travel uphill?" If you don't know the answer to that question, you should probably get the book. If you do know the answer, get it anyway.
|
|
FREE! Power Practice App from APT
|
 Choose your voltage, choose the number of problems you want to work, and go to town on the new APT Power Practice app. The free app serves up practice problems, reviews the results, gives you the correct answers, and provides you with your score.
|
|
|
|
"Successful and unsuccessful people do not vary greatly in their abilities. They vary in their desires to reach their potential."
John Maxwell
|
Electricity, Power Distribution, and Controls March 18, 19, & 20, 2014 Boston Location: Berklee School of Music 155 Massachusetts Ave., Boston, MA
New Electrics Class! Electricity, Power Distribution, and Controls May 5, 6, & 7, 2014 Baltimore
New! Live Audio Training with top industry professional Harry Netti May 5, 6, & 7, 2014 Baltimore
"I'm walking away feeling more knowledgeable and confident with a renewed sense of excitement about our field." - Jamie Stepp, Desmoines Performing Arts |
Entertainment Electrics on DVD |
 Don't miss PLASA Focus Baltimore at the Reitz Arena on the campus of Loyola University, May 8 & 9, 2014. The Professional Development Program will include free seminars with the leading professionals of live event production. |
|
 |
|
