Lighting Controls

UL924 Bypass/Shunt Relays

Shunt Relay Applications

Our Emergency Bypass / Shunt Relays are UL924 listed and suitable for shunting around wall switches in order to turn on emergency lighting in the event of the loss of normal utility power.

When normal power is present, the ESR relay coil is activated and the emergency panel is fed from normal power. The lighting load can be switched on/off using an individual wall switch.

When normal power drops out, the ESR coil is deactivated and N/C contact falls closed. The automatic transfer switch changes over to backup (generator) power, and the lighting load is illuminated regardless of the position of the wall switch or controller scheme.

Standard Shunt Application Click here to show and hide diagram

Wiring Procedure
  • Turn OFF Normal Panel breaker and Emergency Panel breaker
  • Connect Emergency Hot to BLUE wire of ESR, and also to input side of wall switch.
  • Connect YELLOW wire of ESR to output side of wall switch, and also to Load.
  • Connect Emergency Neutral to Load.
  • Connect Normal Hot to White/Black (120 Vac units) or White/Brown (277 Vac units) wire of ESR.
  • Connect Normal Neutral to White/Yellow wire of ESR.
  • Individually cap all unused wires of ESR unit.

Zone Control - Fire Alarm Input Click here to show and hide diagram

Enclosed Relays:

Single Switch Application (Use Normal Light as Emergency Switch) Click here to show and hide diagram

ESRT RF Test Fob

By using one of these models, normal and emergency lighting can be controlled by a single wall switch. When normal utility power is present, the emergency lighting load will function as a normal light. When normal utility power is lost, the emergency lighting will automatically be illuminated.

Suggested use: classrooms, office areas, or any lighting zone controlled by a single wall switch.

Models with RF Test Fob Capability

ESRBE01C-RF for 120 Vac lighting
ESRBE277C-RF for 277 Vac lighting

Models without RF Test Fob Capability

ESRBE01C for 120 Vac lighting
ESRBE277C for 277 Vac lighting

Keep your inspector's feet on the ground.

Make field inspection easy with remote wireless test fob (ESRT) and RF enabled shunt relay models
(Look below for more info).

Remote Test for RF-Equipped ESR Models

Models ESR2401B-RF, ESR2402B-RF, ESRBE01C-RF, ESRB01C-RF, ESRBE277C-RF, & ESRB277C-RF are equipped with a wireless receiver which responds to signals transmitted by the ESRT remote test transmitter. When the signal is received, the coil of the relay is disconnected, allowing the emergency power to flow to the contacts of the relay, thus switching the designated emergency lighting on. For this operation to occur, the light switch or lighting control must be off during the test procedure.

Together these models are used to enable an inspector, in accordance with Article 700.3 of the 2011 NEC
(National Electrical Code), to easily activate the UL924 Emergency Bypass / Shunt Relay wirelessly with the ESRT remote test transmitter, as to prove the ability of the system to bypass the wall switch or other lighting control.

Functional Devices Gives You Two Ways to Meet Article 700.3 of the 2011 NEC
(National Electrical Code)


Track Mount

Model # Description
ESRM2401BUL924 Panel Relay 4.00x1.25in 20 Amp SPDT 24 Vac/dc/120 Vac
ESRM2402BUL924 Panel Relay 4.00x1.25in 20 Amp SPDT 24 Vac/dc/208-277 Vac
ESRM2402SBUL924 Panel Relay 4.00x1.60in 20 Amp SPST + Override 24 Vac/dc/208-277 Vac
ESRMH1CUL924 Panel Relay 4.00" x1.50" 15 Amp SPDT 10-30Vac/dc/208-277 Vac
ESRMNU1CUL924 Panel Relay 2.75x1.70in 15 Amp SPDT 10-30 Vac/dc/120 Vac
ESRMU1CUL924 Panel Relay 4.00x1.50in 15 Amp SPDT 10-30V ac/dc/120 Vac