Intro to Company Switches for Temporary Show Power


Company Switches – Questions to Ask…

When making specifying and purchasing decisions regarding electrical equipment for entertainment venues there are many factors to consider. When challenged with choosing between company switches and standard disconnect switches, the top of the priority list should always be safety. While disconnect switches may often be the more affordable option, the value added into a company switch becomes apparent once all factors are considered.

What is a Company Switch?

A company switch is a power tap box that portable lighting, sound, automation, motors, and power distribution boxes can be plugged into. Often located backstage or in hidden areas of theaters and arenas, standard company switches are rated 100 – 400 amps. Company switches usually consist of a main circuit breaker and connection chamber; a common configuration is 208/120VAC 3-Phase 5 Wire. Equipment connections in the U.S. are typically made via female cam-style connectors. Color-coding for 208/120 is most often Red-Phase A, Black-Phase B, Blue-Phase C, White-Neutral, Green-Ground. However, additional options and configurations are available per customer requirements.

What Should I Consider When Selecting a Company Switch?

Safety is the primary concern in any production, especially when dealing with live power. A safety-interlock preventing access to live connections is critical. The door of a company switch should be safety-interlocked to only allow access to the connection chamber. Access to the deadfront-protected circuit breaker compartment should only be permitted after the main circuit breaker is physically turned to the off position. Further safety recommendations include indicator lights that show when power is being fed to the unit and also when upstream power has been cut to the unit, signaling that it is safe to perform maintenance or repairs.

Verifying that the assembly has passed a series of performance and safety tests and is specifically designed for the intended application is critical. Company switches that are third party certified undergo rigorous tests to ensure the safety of the units. Underwriters Laboratories (UL) is a widely recognized, independent safety and certification organization. In order to receive UL certification, company switches must pass temperature, short circuit and environmental tests. The use of Company Switches that are not UL Listed can result in less than desirable performance, but more importantly, might be unsafe.

In order to restrict operation to authorized personnel, Company Switch assemblies should be equipped with a padlockable main access door allowing access to the connection chamber only. It is also beneficial for the interlocked circuit breaker handle to be padlockable so the circuit breaker can be locked in the off position, thereby preventing unauthorized use.

Since Company Switches are typically installed close to the stage for accessibility, it is important to ensure the unit remains hidden from the concert-goers’ view. Some Company Switch manufacturers provide options such as a wrinkle black finish and other custom colors to match the surroundings. Enclosures can also be furnished with a flush front and recessed circuit breaker handle, or a surface mount design that can be positioned unobtrusively in the background and prevent anything from catching on the handle.


Various facilities may have power requirements that cannot be met with an off-the-shelf solution. This is often true with large scale venues that have tailored designs to suit particular needs, such as:
• Flush Mount/In Wall Design
• Custom Finishes and Colors
• 100% Rated Breakers
• Bare Wire connectors behind interlocked doors
• Isolated Ground
• Dual Neutrals
• Reverse connectors (Male for N+G) to ensure that phase connections cannot be mistakenly connected to the neutral or ground
• Posi-Lok or Pin & Sleeve connectors
• Auxiliary GFCI power outlets
• Meters & Indicator Lights
• Custom Modular Units for larger power needs

Download Company Switch Specifications for Engineers here.

As a manufacturer of safety-interlocked power distribution equipment since 1991, ESL specializes in engineering safe solutions for custom Company Switches. ESL has had the opportunity to provide standard and custom Company Switch assemblies to venues such as Madison Square Garden, Rose Bowl, UCLA Pauley Pavilion, L.A. Live, Los Angeles Stadium, Las Vegas Stadium, and Kannapolis Ballpark to name a few. Visit to learn more about ESL’s Company Switch product line.


Eight Things to Consider When Selecting a Company Switch

There are a number of options to consider when selecting and installing a company switch. Below is a list of 8 key items to answer before purchasing your unit.

1. What is the incoming wire size to be accommodated?
It is important to match the incoming wire size; you don’t want to have lugs on the company switch that are too small to accept the feed wires available at the installation. Make sure to indicate where the conduit will enter the enclosure.

2. Is 200% neutral required?
If unbalanced power is a problem, then an oversized neutral can be specified. If the company switch will be feeding more than one set of equipment, dual neutrals may be necessary. Depending on the amperage, there could be six cam-lock receptacles instead of five.

3. Is isolated ground required?
If the company switch will feed a sound system it is common to isolate the ground from the equipment ground in order to provide a noise-free ground return. If this is the case, an isolated ground is recommended.

4. Are direct-wire lugs needed?
If the equipment that is to be connected to the company switch does not have cam connectors available, direct-wire lugs will allow bare-wire ends to be connected.

5. Is a digital ammeter required?
An ammeter will allow quick and easy reading of the current being drawn through the company switch at a given time.

6. Is an interior work light required?
This option is very useful in dark theater environments, providing a lit chamber makes for easier connections.

7. Will the switch be inside (NEMA Type 1 enclosure) or outside (NEMA 3R enclosure)?
Standard ESL company switches are NEMA Type 1 however, if your unit will be installed outside, NEMA 3R should be specified.

8. Will the company switch use an electrical interlock or a mechanical interlock?
A mechanical interlock is more reliable; an electrical interlock can fail and expose live parts, while a mechanical interlock is a rock-solid way to ensure power is off to the company switch.

Interested in learning about ESL Company Switch features? Watch our ShowSwitch – Company Switch video here!

ESL Power Systems would be happy to discuss these options with you and ensure you get the right company switch for your venue! Contact us at 1-800-922-4188 or for more information.

What is a Company Switch?

Company Switch Banner

Many engineers may know that during the planning and design stages of a project, an electrical disconnect will be needed. However, do you really know what you’re specifying, and what the differences are between your disconnect options? A question not so rarely asked by many engineers is, “What is a Company Switch?”

Here’s your short, to-the-point answer if you are one of the many who aren’t quite sure:

A Company Switch is a specialized type of electrical disconnect that is used extensively in the entertainment industry for set stage applications (such as lighting) by entertainers, road-shows, media personnel and the like. Company Switches include cam lock receptacles to allow single-pole cam connections to be made quickly and easily. Company Switches incorporate safety features and ease-of-use features that are not found in simpler electrical disconnects. These include safety-interlocked circuit breakers and lights to indicate which phases are live.

Any time there is a need for safe and easy connections to facility power, a Company Switch is the obvious choice.

ESL is here to help:

ESL Power Systems’ Company Switches utilize a mechanically interlocked safety scheme. This prevents access to live parts inside the Company Switch by interlocking the circuit breaker with the door handle. In order to plug in cams it is necessary to open the access door, which in turn disconnects the breaker.

ESL Power Systems’ Company Switches have lights to indicate when cams are inserted, and when power is available (circuit breaker is on). These lights are easily visible even in darkened theaters and performance spaces.

For a more in depth look at Company Switches, stay tuned for part two, “Eight Things to Consider When Selecting a Company Switch.”

Let us make your job easy, Download our Company Switch Standard Specifications or contact us if you have additional questions.