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Prevent Backup Power Failure – Use UL 1008

July 12, 2017July 13, 2017Patrick Evans

Use UL 1008

To ensure the safest and most reliable transfer switch equipment is purchased, the UL 1008 requirement should be included into project specifications. Whoever is responsible for the transfer switch selection process should be aware of criteria that helps classify each UL Listing.

Why UL Listing Matters?

In order to minimize the chances of backup power failure, it is important to make sure that transfer switches and other electrical equipment are properly certified. The UL 1008 Listing is not just a transfer switch performance standard; it is an industry standard for design and construction certification. In order to receive a UL 1008 Listing, a transfer switch must undergo rigorous testing by the independent certification agency.

UL 1008 standard was established by Underwriters Laboratories to help protect against transfer switch dangers and failures. Since its inception, the UL Certification process and standard have been modified and updated on a regular basis. The 7th Edition of UL 1008, which became effective in 2014, resulted in significant changes to the short-circuit ratings shown on all transfer switch products within the industry.

The additional requirements now include:

Withstand and close on ratings (WCR) covering severe fault currents
Bolted faults and short circuits to ensure the device can carry rated currents
Endurance tests which record performance of the transfer switch at each ampere level

The File number is located on top of (or next to) the UL mark; which is identified with the letters “UL” inside a circle and the word “Listed.”

When a transfer switch has successfully passed all of UL’s tests, the manufacturer is then permitted to label qualifying products with the UL mark. The UL 1008 transfer switches are given one of three labels:

Non-automatic transfer switch
Automatic transfer switch
Transfer and bypass isolation switch

Know How to Identify the UL Mark

After passing the tests, UL Listed products are required to carry a marking to identify the Listed company. A (label on a) transfer switch can consist of the company name, a trade name or trademark, or the Listee’s UL file number. The File number is located on top of (or next to) the UL mark; which is identified with the letters “UL” inside a circle and the word “Listed.”

Misconceptions with UL Certification

Knowing there is a lack of education in the market, many companies will state their device “meets UL standards.” This does not mean it was tested and is “UL Listed”. When you are evaluating products, look for the logo and category code. This code can be used to verify the listing and the standard to which it was evaluated.

Below is a list of common UL Listings associated with transfer switches and emergency power connection equipment.

UL 1008 Transfer Switch Equipment
UL 1008 is specifically designed for transfer switch equipment. Products with a UL 1008 certification means the whole assembly is certified and has undergone rigorous testing to ensure 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 inspection process is also easier when emergency power transfer switch equipment is UL 1008 Listed.

UL 1773 Termination Boxes
This standard is intended for applications that are wired via terminals (usually permanent) and does not contain switching equipment.

UL 98 Enclosed Dead-Front Switches
The UL 98 standard applies to double throw or knife edge switches (air switches), and does not allow the incorporation of circuit breakers.

UL 67 Panelboards
This standard does not apply to transfer switch equipment. UL 67 covers panelboards for the control and protection of electric lighting and appliance branch circuits, and power circuits, including feeder distribution panelboards.

UL 50 Enclosures for Electrical Equipment, Non-Environmental Considerations
A UL 50 Listing only certifies that the actual box is UL Listed for a specific environmental condition (Type 1, Type 3R, etc.). This does not mean that the whole assembly (enclosure plus components) has undergone testing for the intended application.

Let ESL make your job easy! Download our UL 1008 Listed Manual Transfer Switch specifications for engineers.

What is a Company Switch?

July 28, 2016August 16, 2016Bill Hallemeyer

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.

3 Benefits of Well Written Specifications

July 23, 2012August 23, 2017David Hellmers

Whether you are an engineer, end-user, manufacturer, contractor, or distributor, the process of composing or evaluating bid documents can be quite complex and time-consuming. Keep in mind that the end goal is to deliver a high quality product at a fair price that meets or exceeds customer expectations. However, without clear guidelines, many items might be left open to interpretation. At the end of the day, one bidder is quoting a blue minivan and another a red sports car when the customer was really wanting a white pick-up truck. Meanwhile everyone involved is pulling their hair out trying to determine what to offer or attempting to evaluate dissimilar bids. Sounds all too familiar, right?