For A Complete Line of UL 1008 Listed Emergency Power Solutions – Look No Further

For A Complete Line of UL 1008 Listed Emergency Power Solutions – Look No Further

Announcing DualConnect™, ESL’s New Dual Purpose
Docking Station

CORONA, California, October 22, 2021 – ESL Power Systems provides a number of solutions for the growing market to both load bank test, and provide temporary back up to a permanent generator.

For over 10 years, the ESL TripleSwitch® has provided the leading solution to perform both of these functions, and meets the required NEC codes for this application. ESL is now excited to announce the addition of yet another UL 1008 Listed Emergency Power Connection Solution, The DualConnect™ Dual Purpose Docking Station!

Available from 400 to 5,000 amps and rated up to 65kAIC@600VAC, ESL is now the only manufacturer that can provide a complete line of UL 1008 Listed Emergency Power Connection Solutions for all your design needs.

The TripleSwitch is the cost effective, most user-friendly solution for new construction design or adding a permanent generator to an existing facility. Utilizing the (3) circuit breakers necessary for this type of application, it provides the overcurrent protection and safety interlock between permanent and portable generator, without the need for key locks or breakers in separate locations.

The standard TripleSwitch is configured with an AUX Contact for the remote annunciator.  It is also provided with -a shunt trip on the load bank breaker, to dump the power to the load bank, in case utility power is lost during a load bank test. This meets the requirements of NEC Code 2017 700.3 (F).

However, there are applications where multiple generators or existing generators need the ability to be load bank tested and also have provision for a connection of a back-up temporary, portable generator. For these projects ESL’s DualConnect – Dual Purpose Docking Station is the right solution for the application.

Where multiple generators are utilized, the design will typically include the necessary switchgear and controls to selectively perform your load bank test or temporary back-up of the permanent generator. In addition, many existing permanent generators need back-up and the capability to do lower cost portable load bank connection. 

300A DualConnect™

Having a single unit to quickly connect a portable load bank or portable generator while using the existing switchgear overcurrent protection when possible minimizes the total project cost and redundant overcurrent devices.

The Dual Connect – Dual Purpose Docking Station provides the flexibility needed to meet your design criteria and is highly customizable with various optional features. Depending on the emergency back-up system design for multiple or existing generators, the DualConnect is available in three different versions.

No Breaker: Where all the controls and/or breakers are currently in the emergency power system. The interlock between the permanent generator and temporary back-up generator is accomplished by a key interlock between an appropriate designated breaker and the DualConnect portable generator cable access door.

One Breaker: Provides overcurrent protection to the unit and functions as the disconnect for both the load bank and portable generator cams. The interlock between the permanent generator and temporary back-up generator is accomplished by a key interlock between an appropriate designated breaker and the DualConnect portable generator cable access door.

Two Breakers: Provides overcurrent protection to the unit and functions as the disconnects for both the load bank and portable generator cams. The interlock between the permanent generator and temporary back-up generator is accomplished by a key interlock between an appropriate designated breaker and the portable generator breaker in the DualConnect. All of ESL’s DualConnect units with 2 breakers can be configured to meet NEC700.3(F) if required.

To learn more and get downloadable specifications for ESL’s DualConnect – Dual Purpose Docking Station visit:

About ESL Power Systems, Inc.

A 100% employee owned company, ESL Power Systems, Inc. is an innovative global leader in the design and manufacturing of cord-connected electrical equipment for industrial and commercial applications and is also the premier custom control panel builder in Southern California.

Media Contact:
Erika Thorson
ESL Power Systems, Inc.
2800 Palisades Dr.
Corona, CA 92878
+1 (951) 739-7000

4 Natural Events That Could Trip Up Your Business

Natural events have become a common occurrence in many parts of the US with a growing number of devastating natural disasters occurring in recent years. Preparing your business for emergency back-up power in the midst of a natural disaster such as an earthquake, hurricane, ice storm or flood is crucial for business continuity.


In the US alone, the National Earthquake Information Center locates about 12,000-14,000 earthquakes per year. Globally there are approximately 55 earthquakes per day averaging out to 20,000 a year!

During an earthquake, a building’s emergency equipment may inevitably experience vigorous shaking and movement depending on the magnitude. Acquiring back-up equipment that is OSHPD “OSP” Special Seismic Certified provides enormous value in knowing your equipment has been shaker-table tested and certified to endure major earthquakes without fail. However, earthquakes aren’t just about shaky buildings, earthquakes also have the power to cause damage to electrical grids and powerlines. When either of the two are down, electricity and power can go out resulting in a loss of power to your business. This ultimately results in loss revenues, product and production to name a few. Where critical facilities are concerned, this could mean life or death.

Wind and Storms

High winds from hurricanes, tornadoes, and severe storms affect emergency power every year and are one of the most common causes of power outages. In 2020, NOAA reported a record-breaking 30 named storms (top winds of 39 mph or greater), of which 13 became hurricanes (top winds of 74 mph or greater), including six major hurricanes (top winds of 111 mph or greater). 2020 became the year with the most storms ever recorded in the continental United States. A report from Climate Central states that 44 percent of power outages are caused by storm events which negatively impact businesses and homes.

Strong winds tend to blow large debris resulting in broken power lines and utility poles. They can also cause lines to swing together which can result in short circuiting utility power. Strong winds are also traced to the cause of wildfires. Utility companies have begun to implement “Public Safety Power Shutoffs” in order to tackle the event of severe winds and prevent wildfires from occurring. With consistent power outages during severe winds, businesses are forced to find alternatives to utility power in order to keep the lights on during these long shutoffs.

Ice Storms

Ice storms fall into the “winter weather” category and occur in the U.S. primarily during the months of December and January. Also known as freezing rain, these storms occur when rain freezes and accumulates on surfaces such as trees, power lines, and the ground.

Severe damage to trees and power lines begins when ice accumulates between a quarter- and half-inch. When these ice droplets accumulate onto powerlines it can add up to 500 pounds of extra weight. With the amount of weight added by ice layers, trees and utility lines tend to fall and result in damage to roads, homes, and businesses. It can take quite a while for trees to be removed from roads and powerlines to be repaired, this can result in a loss of electricity and heat for many days. In January 2020, an Atlanta ice storm left half a million people without power, some for more than a week while utility companies tried to repair lines. Estimated total losses reported for this storm reached upwards of $48 million. In mid-December of 2020, an ice storm left more than 500,000 without power in parts of Texas, Oklahoma and Arkansas. At the time, it was called one of the most destructive ice storms seen to the electrical utility infrastructure in those areas. In February 2021 more than 700,000 people were without power due to ice storms in eight states including Nevada, Oregon, Washington, Kentucky, North Carolina, West Virginia, and Virginia.

Knowing that ice storms can last up to a few days, preparing ahead of time is the best decision. Businesses with back-up power solutions are able to sustain these winter events and keep the lights and heat on when it is needed the most.


According to the department of agriculture, ninety percent of all natural disasters in the United States involve flooding. Additionally, high-risk flood areas are not the only ones at risk, about 25% of flood insurance claims come from moderate-to low-risk areas.

Floods are caused by spring thaw resulting in the overflow of rivers, waterways, dams, etc. They are also caused by coastal flooding due to hurricanes, tropical storms, and heavy rains. Flood surges that occurred in Hurricanes such as Sandy and Katrina severely affected emergency power. Flood damage poses one of the greatest risks to on-site power.

Considering the location of your emergency back-up equipment is paramount when planning for possible flood-damage. The lowest level of a building is the most likely to flood knocking out emergency power distribution equipment, such as transfer switches, rendering switches inoperable. Organizations such as Medical facilities and Universities have begun mounting back-up equipment on the second floor keeping all equipment dry and operational during a flood.

Natural disasters are in abundance. All the U.S. incurs some sort of natural disaster that knocks out power daily. Designing on-site emergency power back-up systems is crucial to business survival and recovery.

Learn how to protect your business with ESL’s back up power solutions.

Emergency Power Q&A

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.


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.


 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

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


 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.


 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


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!

Public Safety Power Shutoff: The Power of Being Prepared

Public Safety Power Shutoff Blog header

Is your business ready when the next Public Safety Power Shutoff occurs?

Do you have a plan to get your business up and running if the power is out for days?

Emergency back-up power contingencies must be at the core of your business power shutoff plans now that local energy companies may need to turn off power during extreme weather conditions. According to, “Public Safety Power Shutoffs (PSPS) are an operational practice where we [CA local energy companies] preemptively shut off power in high fire risk areas to reduce fire risk during extreme and potentially dangerous fire weather conditions” (

ESL’s quick connect manual transfer switch (StormSwitch™) provides a cost-effective solution for municipalities and businesses ready to take action in preparation for the next Public Safety Power Shutoff.

When considering which manual transfer switch is best for your business during a Public Safety Power Shutoff, there are a few factors to consider:

  1. Ampacity Draw/Usage
    The first step in selecting a transfer switch is determining what ampacity is needed to provide power to the building. In the event of a prolonged Public Safety Power Shutoff, will all of your electrical equipment need to be powered or can you get by with only some equipment being operational? If the entire facility needs to be powered, then the ampacity should match the building’s service. In many cases, only a portion of electrical power is necessary for a facility to remain operational during a PSPS. In this situation, the transfer switch ampacity and subpanel would need to match the ampacity proportion needed.
  2. Permanent vs. Portable generator
    A permanent generator works with an automatic transfer switch (ATS). An ATS transfers the power source from the utility grid to the generator in seconds. While minimizing downtime is a huge advantage, an automatic system can be quite costly when considering the cost of the switch, permanent generator, fuel storage, installation, and regular maintenance of generator. A cost-effective alternative for preparing for a PSPS is a manual transfer switch which can allow you to connect a portable generator to your facility during a power shutoff. With a portable generator and manual transfer switch, “quick-disconnect” connections can be established (within minutes) restoring power to your business.
  3. Safety Requirements from Local Jurisdiction
    Local building inspectors typically require all new electrical equipment installed in their jurisdiction to be “Listed” which means the equipment has been approved by Underwriters Laboratories or another recognized test lab. For standby systems that allow portable generator connection, UL 1008 is the proper standard to adhere to. If the equipment is not properly Listed, it may not be accepted by the inspector.

Evaluating a backup system that is suitable to your needs is an important step in preparing for the next Public Safety Power Shutoff. Installation of a manual transfer switch requires some planning, but it can be the difference in your facility being operational versus out-of-business. A PSPS event will last as long as the extreme and potentially dangerous fire weather conditions exist, along with additional time to inspect/repair equipment in the affected area(s) to ensure safe and reliable power restoration. Will your business be the one ready to serve your customers at a time when demand is high?

ESL is here to help you determine which solution is best for your business and what additional options may be helpful. Be prepared. Plan ahead. Learn more about manual transfer switches and how you can keep the lights on during a PSPS event.