When power fails, occupants rely on emergency lighting to safely exit. Branch Circuit Emergency Lighting Transfer Switches (BCELTS) play a critical role by automatically transferring power to emergency sources, ensuring compliance with life-safety codes and reducing risk during outages. A well-designed BCELTS can simplify wiring, improve reliability, and save time for installers.
Functional Devices has long been a trusted name in emergency lighting control with UL924 products that make bypassing switches and overriding dimming simple. Traditionally, these products required a separate transfer switch, adding cost and complexity.
To solve this, we developed the ESR-BCELTS, combining branch-circuit transfer and lighting control in one compact unit. It streamlines installation, supports code compliance, and ensures lights stay on when they’re needed most. In this blog, we’ll highlight how this product simplifies compliance, cuts installation time, and provides a dependable way to keep lights on when they matter most.
Want to learn more or see how the ESR-BCELTS can fit your project? Contact Functional Devices today for details and support.
The ESR-BCELTS to the Rescue
The ESR-BCELTS is designed to automatically transfer a lighting load from a Normal source to an Emergency source, like a generator or inverter, upon loss of Normal power. Depending on the wiring configuration, the device can transfer power to a lighting load, override 2-, 3-, or 4-wire dimming controls, bypass a switch, or do all three at the same time.
Key Features of the ESR-BCELTS
Some of the notable features of the ESR-BCELTS are:
- Wide input voltage range of 120-277 Vac
- Test button in the enclosure lid
- Remote test input for Fire Alarm panels and routine testing
- Rated for 16 Amp Electronic Ballast (LED), Magnetic Ballast, and Tungsten Loads
- Auxiliary contact for status feedback
- ETL Listed to UL1008 and UL924
- Made in the USA of domestic and global parts.
Benefits for Installers and Facility Managers
The ESR-BCELTS makes life easier for both installers and facility managers by streamlining emergency lighting setups. Because transfer and control are built into one unit, wiring is simplified, installation time is reduced, and fewer components mean fewer potential failure points.
For facility managers, this translates to reliable operation, easier maintenance, and a more straightforward path to code compliance. The compact design also frees up space in electrical panels and minimizes long-term costs, making it a practical choice for new installations or upgrades alike.
Simple Wiring & Installation
Let’s explore more specifics on how the ESR-BCELTS should be wired and some of its features that simplify the installation.
The two diagrams below show the wiring configuration for a basic UL1008 transfer application and a UL924 bypass application. For a full list of product specifications, check out the product Datasheet or Bulletin on our website.
The product also offers features that make it versatile and simple to install. The steel enclosure means it is acceptable for installation in Plenum spaces. All field connections are made on terminal strips inside the enclosure. This prevents the need to use wire nuts and extra junction boxes to make terminations. The enclosure also has pre-stamped knockouts on the top and bottom of the enclosure for landing conduit connections.
FAQ About the ESR-BCELTS
Q: What is the ESR-BCELTS?
A: The ESR-BCELTS is a Branch Circuit Emergency Lighting Transfer Switch that automatically switches a lighting load from a normal power source to an emergency source (like a generator or inverter) when normal power is lost.
Q: What standards is it certified under?
A: It is ETL-listed to both UL 1008 (for transfer switches) and UL 924 (for emergency lighting and bypass/override functions).
Q: What load types and voltages does it support
A: It supports 120-277 Vac at 50/60 Hz and is rated for 16 A loads, including electronic ballasts (LED), magnetic ballasts, and tungsten.
Q: Can it override dimming or bypass a switch
A: Yes. Depending on wiring, it can override 2-, 3-, or 4-wire dimming controls, bypass traditional wall switches, or do all of these functions together.
Q: What features aid testing and monitoring
A: It includes a test button on the enclosure lid, a remote test input (for fire alarm panels or routine use), and an auxiliary contact for status feedback. LEDs indicate states: green for normal power, red for emergency power, yellow when load power is available, and blue for fault.
Q: What are environmental and installation specifications?
A: Operating temperature range is –30° to 140° F (−35° to 60° C); humidity is 5 to 95 percent non-condensing. It comes in a steel NEMA-1, plenum-rated enclosure, with field-terminals and knock-outs for conduit top and bottom entries.
Q: What is the expected lifetime and warranty?
A: Mechanically, the relay is rated for at least 1 million cycles. The unit carries a 10-year warranty.
Rely on Functional Devices for Emergency Lighting Control
A BCELTS helps ensure the lights stay on when an emergency strikes. With the ESR-BCELTS, we’re able to offer a more complete solution for our customers’ NFPA 101® emergency lighting needs.
At Functional Devices, we pride ourselves in providing great customer service, competitive pricing, and high quality, reliable products for our customers. You can be assured that, just like all our products, the ESR-BCELTS will be fully tested in our production facility before it makes its way out the door. If you have questions, please contact us!
About Functional Devices, Inc.
Functional Devices, Inc., located in the United States of America, has been designing and manufacturing quality electronic devices since 1969. Our mission is to enhance lives in buildings and beyond. We do so by designing and manufacturing reliable, high-quality products for the building automation industry. Our suite of product offerings include RIB relays, current sensors, power controls, power supplies, transformers, lighting controls, and more.
We test 100% of our products, which leads to less than 1 out of every 16,000 products experiencing a failure in the field.
Simply put, we provide users of our various product confidence and peace of mind in every box.