Electrical Power

Sourcing Wayside HEP Power Systems for Rail Yards

Erika Thorson

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Head End Power Unit Configurations for Passenger Trains

In the late 1990s, the American Public Transportation Association (APTA), implemented practices for Head End Power sources throughout the passenger rail industry.

According to 3.1.3 in APTA RP-R-015-99, Head End Power (HEP) is defined as “A system by which 480 VAC 3-phase electrical power, to operate auxiliaries, is provided to railroad vehicles from a central source via a trainline system. The power source can be locomotive (hence “Head End”), power car, or wayside source.” Read more →

How to Prevent Exploding Reefer Plugs & Connectors

Carlos Valero
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Those who have plugged in Refrigerated Containers (a.k.a “reefers”) know firsthand that water intrusion can cause reefer plugs and connectors to explode.  This is extremely dangerous and can result in injury to the operator, damage to the plug, receptacle, and surrounding equipment.  And obviously, the refrigerated cargo is no longer being cooled.  Experienced operators will even shake the plug prior to plugging in; if they suspect water is inside they know better than to energize the plug.

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Emergency Power Q&A

Erika Thorson

Emergency Power connection solutions Q&A

Many questions arise when beginning your first emergency power connection equipment project. ESL has put together some Frequently Asked Questions from customers throughout the years to assist as you move forward with choosing your back up power solution.

General

Q: How do I know what product will best work with my specific needs?
A: ESL’s knowledgeable sales personnel will gladly assist with helping to identify the proper product for your application. The key factors will be the voltage system and the desired emergency load that is to be fed.

Q: What is UL 1008 and how does it affect me? 
A: Local building inspectors typically require all new electrical equipment installed in their jurisdiction to be “Listed” which means the equipment has been approved by Underwriter Laboratories or another recognized test lab. For standby systems that allow portable generator connection, UL 1008 is the proper standard to comply to. If the equipment is not Listed, it may not be acceptable to the inspector.

Q: Is it difficult to make the generator connection to the StormSwitch®, TripleSwitch® or TempTap® product line?
A: No, they utilize the industry standard 400A series 16 cam-style connectors. ESL’s StormSwitch, TripleSwitch and TempTap are color-coded to the voltage, e.g. 208Y/120 green, white, black, red, blue.

Q: Do the generators have the same color-coded plugs that the StormSwitch, TempTap, and TripleSwitch have? 
A: ESL cannot guarantee that. Industry standard is green for ground, white for neutral, and typically black for “A” phase, red for “B” phase and blue for “C” phase. When entering in an agreement for generator service, it is recommended that you request the aforementioned color-coding for the cams.

StormSwitch

 Q: What are the advantages/disadvantages of using a manual transfer switch with a portable generator versus an automatic transfer switch with a permanent generator?
A: Advantages:
Significantly lower cost
No on-site fuel storage required
No maintenance or standard periodic testing
Easier installation – days instead of weeks
Smaller size
Portable generator can be rented or used at other facilities
Permanent generator requires multiple permits

Disadvantages:
Longer time before generator power is established

Q: Can the StormSwitch be Service Entrance Rated?
A: Yes, the StormSwitch has the option to be SUSE (Suitable for Use as Service Entrance in the USA). This option should only be used when the StormSwitch is installed at the building service entrance.

 Q: What is the reason an additional circuit breaker is available with the purchase of a StormSwitch?
A: Circuit breakers provide over current protection; switches do not. If the supplied generator does not have built in over current protection, then it is recommended that the generator disconnect and the StormSwitch be equipped with a circuit breaker rather than a switch. Also depending on your specific application, you may or may not need over current protection on the utility side. Again, ESL’s knowledgeable Sales personnel will gladly help you in deciding what combination works best for your application.

 Q: How does the StormSwitch compare to a standard “double-throw” or “double-key” transfer box?
A: The traditional “safety switch” and/or “double-throw” switches do not provide the over current protection option that is available in ESL’s StormSwitch. These “safety switch” and/or “double-throw” switches are intended for “hard wiring” and therefore would require a licensed electrician (difficult to find one available as they are in high demand during power outages) to connect and disconnect the generator.

 Additional StormSwitch Q&A can be found here

 TempTap

 Q: What is a TempTap?
A; Also referred to as a docking station or tap box, ESL’s TempTap is a means for direct connection from the generator to the building’s switchgear.

Q: Is there any protection offered in a TempTap?
A: Locking doors and internal connection points to keep unauthorized persons from the device. The TempTap is designed to be a safe and simple pass-through box mounted to the outside of a building. It should be used in conjunction with a with a transfer switch or a utility disconnect.

TripleSwitch

 Q: What is the TripleSwitch designed to do?
A: The UL 1008 Listed TripleSwitch was designed to simplify and reduce the cost of load bank testing procedures and to provide a backup for the permanent generator. This unique 3-way manual transfer switch system provides a quick and completely safe way with mechanically interlocked breakers to supply power to the facility from a portable emergency standby generator in the event the utility power is disrupted due to a power loss when the permanent generators are offline.

Q: I know it’s easy to show the ease of use and the safety aspects of the TripleSwitch, but are there other advantages as well?
A: Yes, an added benefit is a reduction in down time when connecting and disconnecting for load bank testing. Having quick connect cam locks for connecting the portable load bank means set up time is reduced to minutes not hours.

Q: How difficult is this to install a TripleSwitch on a job site?
A: Being UL1008 Listed means the TripleSwitch is built in an enclosure designed to provide the proper bend radius and space for the cable amperage being used. The TripleSwitch is an integrated unit with all necessary breakers and cam-lock connections. This means the contractor is installing one unit thus reducing conduit runs and cable lengths as opposed to alternative multiple unit and switchgear solutions that would require multiple conduit runs.

Q: Can I install the TripleSwitch with an existing permanent generator?
A: Yes, very easily. Being an integrated unit, you typically do not need to design-in new breakers and interlock methods. It is a drop-in solution connecting into the existing connection between the ATS and permanent generator.

ESL’s knowledgeable sales personnel is here to answer any additional questions you may have. Please feel free to contact us! ESL is always here to help!

3 Reasons Why UL 1008 Should Be Specified

Erika Thorson

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When comparing NRTL Listings of different products, it is important to know what the appropriate UL standards are and how they apply to your specific application. You may not always be purchasing what you think you are purchasing. UL 1008 was specifically created for transfer switch equipment. Products with a UL 1008 certification ensure the complete assembly is certified and has undergone rigorous testing to validate performance, safety, and reliability. Non-Automatic transfer switches that are Listed under the UL 1008 standard are evaluated in accordance with Articles 517-Health Care Facilities, 702-Optional Standby Systems of the National Electrical Code (ANSI/NFPA 70) and the National Fire Protection Association Standard for Health Care Facilities (ANSI/NFPA 99). The local inspection process by the AHJ is typically much easier when emergency power transfer switch equipment is UL 1008 Listed. So what are some basic reasons to purchase UL 1008? How about these three…

  1. Your UL 1008 listed Manual Transfer Switch will be listed the same as an Automatic Transfer Switch unit. This means continuity of Listing in all your transfer switch designs.
  2. No need to “reinvent the wheel”. With a UL 1008 listed transfer switch for your project, there is no need to verify if your design meets all the requirements for a transfer switch. This should shorten your design time on your project.
  3. By specifying a UL1008 Listed unit, you are assured that the unit supplied is not just a UL 50 enclosure and/or UL Listed components but has been tested as a complete unit. AHJ are becoming more aware that a manual transfer switch should be listed the same as an automatic transfer switch since they perform the same basic function.

When there is a proper solution why go any other way? It just makes sense!

ESL’s line of emergency power connection equipment for commercial and industrial applications is UL/cUL 1008 Listed for StormSwitch® – Manual Transfer Switches up to 3000A, TempTap® – Generator Docking Stations up to 3200A, and TripleSwitch® – 3-Way Manual Transfer Switches up to 3000A. To get a quote on your next project contact us!

Intro to Company Switches for Temporary Show Power

Bill Hallemeyer

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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
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.

Security
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.

Aesthetics
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.

Customization

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 www.showswitch.com to learn more about ESL’s Company Switch product line.