Power Distribution Systems on Movie Sets|
Article - March 22, 2016 By LarsonElectronics.com
Power Distribution Systems on Movie Sets
Equipment found on movie sets, such as industrial lights, sound boards and filming monitors, have special electrical requirements. As a whole, the devices demand considerable amounts of electricity to maintain operation. Individually, each component may have different electrical needs.
Below covers the function of power distribution systems on movie sets, and new trends in the industry that could change the way power is distributed on filming locations.
Power Distribution and Movie Sets
The main role of power distribution systems involves managing the electrical requirements of devices on the set. It does this by taking raw, high voltage power and stepping it down to usable voltages. The unit may also spread out or distribute the power to multiple sources, so more than one device can use the converted power from the unit. Safety is a primary concern when working with exceedingly high voltages and sensitive equipment. Because of this, power distribution systems also provide circuit protection to prevent overcurrents from damaging connected devices. A power distribution system may offer different levels of protection for equipment plugged into the unit, such as large capacity protection for feeder cables and small capacity protection for small loads.
To prevent overloading a power distribution unit, workers use “paper loads” when calculating for the amperage requirements of a device. Paper load refers to an upwards adjusted calculation of the actual load. For example, if the actual load of a fixture is 8.7 amps, its paper load would be 10 amps, or a rounded up figure based on the actual load. This creates a cushion for unforeseen spikes above the unit’s amperage rating. In particular, movie set lights are known for facilitating such spikes when turned on or toggled rapidly.
The cushion is also useful for last minute requirements on the location. If the set suddenly called for a small light or speaker to be plugged in, it could be plugged in without overloading the system (as long as it does not exceed the threshold of the system). Some professionals calculate for the paper load differently by adding up the actual load values of the equipment and adding 10 percent to the total.
Managing Power Distribution Systems
On movie sets, the person responsible for setting up power distribution systems is the Best Boy. This individual, who also assists the Gaffer or head of the electrical department, mostly handles the deployment of single-pin power distribution units. Both professionals must also accurately map out the most efficient way to distribute electricity throughout the set. This process often involves toggling breakers inside the panel box, while simultaneously using a tester to check on various circuits around the location.
When portable generators or alternators are used on location to push power to remote equipment, it is best practice to deploy such units close to the set, where filming is being conducted. This is done to minimize the length of the cables between the devices and the power supply. It is important to consider that the longer the cable has to be, the thicker and heavier it ends up being. Using low quality, long cables could result in voltage drops below the standard of two percent (also known as line-loss), causing malfunction or inconsistencies in equipment performance.
For portable power supplies, noise can become an issue when syncing audio while filming on the set. To prevent disruption, it is common practice to deploy the mobile generator behind a wall or downwind. Alternatively, one could run the generator from the back of a van to muffle the noise, while using thick, twist-lock extension cables to connect the generator to a transformer. Access to a multi-phase, multipole isolating switch must also be considered (especially for three-phase supply units), which can be utilized to disconnect electrical power from the system during an emergency. One should note that electrical power distribution on movie sets in the United States is different from locations in Europe, due to varying regulations and equipment.
Solar Power Distribution Trends
The movie industry is known for consuming large amounts of electricity during filming. In order to address this growing concern, some producers are turning to solar power distribution systems. This trend is steadily increasing in the sector, with notable applications in Christopher Nolan’s movie Inception, ESPY Awards, LA Marathon and Teen Choice Awards. While filming the movie Inception, the crew deployed large solar panels, capable of powering up to eight homes. The panels were connected to 72,000-watt generators that were both noise and emission-free. For maximum exposure, the solar panels were rigged to follow the position of the sun using a manual electric tracking feature.
Solar power distribution units were also utilized during the filming of Bad Words, a movie produced by Jason Bateman. The group’s system included four, 20K mobile solar generators, solar light towers, 10 PV panels, two inverters and a large battery bank. This type of distribution deviates away from the traditional, centralized utility model. Instead, movie sets generate their own power through the panels, while converting the power to usable voltages (also known as distributed generation, or the decentralized production of electricity using small-scale configurations).
Compared to utility-scale solar energy generation, which generates electricity from one location only, i.e., a solar energy plant; from a cost perspective the costs are significantly lower. Distributed generation strongly relies on the advancement of solar technology. Therefore, at this time, such systems are limited to very small locations, such as movie sets, outdoor concerts, micro-communities and remote processing plants.