Power Cables

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There exist a variety of power cables used in live Entertainment. Each have rather specific use, and some care must be taken when using adapters, splitters and connecting to end user equipment. If you aren't an entertainment electrician (or even if you are) you should always be careful when working in close proximity to multiple cables.

Basic Electricity

Often times, electricity is described similar to a water pipe.[1] While it is debatable whether the analogy is accurate or not, we will simply use water flowing as the analogy to describe how it does work without getting into the physics of the differences.

There are two primary values in electricity that electricians are concerned with. VOLTS and AMPs. Volts can be thought of as the amount of electricity available. Amps would thus be described as "how quickly the Volts travel" down electrical wires.

When a device is plugged into the circuit, it presents a certain amount of drain on how many Volts and Amps can be driven through the wire. Every time a device is plugged, it forms a connection, allowing Volts to travel through the device, at a certain "speed" of Amps. This drain is refereed to as Watts, the unit of Power.

If we haven't lost you yet, this is where the wiring calculations come into play. The Watts divided by the Volts produces a number of Amps. Most cabling and plugs are rated based on the number of Amps at a certain voltage they can carry.

For example, the 12AWG[2] rated cable can handle up to 20 AMPs. In America, at 120 V, that means a 20AMP cable can handle up to 2,400W or 2.4kW. As with most safety protocols of course, the lowest rated capacity is the one you should be designing the circuit around. With different wires, plugs, cables and breakers, make sure all the gear can handle the rated Wattage.

Terms

Electrical cables use a lot of slang, as defined here:

  • Jumper
    • Cables that are meant to go directly between 2 devices. Also may mean a short cable.
  • Male
    • The end of the cable with prongs, for connecting into the mated female sockets.
  • Female
    • The end of cable with a socket, for connecting to mated male prongs.
  • Turnaround aka Gender Changer
    • Adapters that change the "gender" of the end of a cable. Very common for Powercon or Feeder Cables.

Feeder Cable

The highest rated temporary cables used by electricians. These cables connect from service panels to distros to provide usable power for gear. They are arranged in bundles of 5, with Male and female ends, containing Ground,(Green) Neutral, (White) and 3 Phases of Hot (Black, Blue, Red). One slight annoyance with these cables revolves around a non standard arrangement where some distros will use different male and female couplers for Hot vs Ground and Neutral. A number of turnarounds exist to change them. Their maximum rated ampacity is up to 400amps per Hot leg, though many distros and service panels are rated for lower usage.

Cube Taps / Two-fer / Power Strip

Cube taps, Two-fers and Power strips allow splitting a power source to multiple devices. They can be further subdivided by the type of electrical connectors they connect, such as "Edison cube tap" or "Stage pin twofer". These are sometimes also known as squids, particularly when they take a single power input, and distribute them to multiple outputs, with a short tale on each line, thus when held up, resembling a squid.

These should not be confused with breakout boxes which take different voltages and have breakers for the circuits.

Edison

The Edison power cable is the most common type of cable used in electrical work in the United States of America. It is represented by a two pronged plug that may also have a third prong for grounding. The standard Edison has a maximum rating for 2400 Watts at 120 Volts when connected to 12AWG wire. There are other types of plugs that have a lower rating, including a 15 amp, and a 10 amp with no grounding pin.

Powercon

PowerCon is an electrical plug. It works similar to Speakon and is generally rated at 20 amps. It can be locked into the plug so it is a bit more reliable than Edison, though they require a little more care for planning out power runs. Powercons come in two color types, to differentiate power incoming or outgoing that cannot be cross matched. Blue plugs, and outlets indicate power incoming to a device, while grey plugs are used for outgoing power from a device. A standard powercon cable jumper comes with a blue and White plug on each end.

Stage Pin

Stage Pin is a standard power cable used in stage lights with dimming power. It lies flat on it's surface which helps to make it less of a tripping hazard. The plugs are arranged in a straight line. There are 2 plugs on one side with a ground plug in the middle. These range in different sizes, the most common being a 20Amp 120v connector. Other sizes include smaller, 10amp 120v, and distro and breakout box style 100Amp 120v.

U.K.

UK plugs are the standard electrical plug for the United Kingdom.


References

  1. Check out this Wikipedia article for more info
  2. American Wire Gauge