Single-Pole Heavy-Duty Latching Relay

Engineered to be one of the most reliable relays on the market, the Single-Pole Heavy-Duty Latching Relay is suitable for all types of loads, including capacitor-corrected HID ballasts. The relay has a set of built-in auxiliary contacts that allow the connected controller to determine the position of the load contacts. A manual operation lever and indicator are also built in for convenient operation and status check at the panel.

Purchase Products

Product features

Built-In Dual Diode

  • Rectifies full-wave ungrounded AC signal to switch the relay using a positive or negative pulse.
  • Acts as a gate for the switch signal in series with the relay coil.

Easy Wiring

  • Line-voltage leads conveniently color-coded.
  • All connections made with screw terminals.

Manual Override Switch

  • Provides a means to override control during commissioning or in an emergency.

Industry Standard for Decades

  • Durable design reliably controls lighting and plug loads while prioritizing safety.
  • Mechanical latching requires no energy to maintain state.
  • Two-wire connection provides command and reads relay status without using an input.


  • Works with all MACH‑ProLight™ -R models and -U models that have their outputs configured to relay.
  • Each relay supports up to six Douglas Lighting series 8700 switches. One switch controls up to four relays.

Manufacturer Warranty

  • 2 years.

Technical specifications

Supply Voltages

  • Load terminals 347 VAC maximum. See contact ratings for more information.

Contact Ratings

  • UL Listings:
    • 20 A 347 VAC General Use.
    • 20 A 300 VAC General Use.
    • 20 A 300 VAC Ballast.
    • 16 A 120/277 VAC Ballast.
    • 2,400 W 120 VAC Tungsten.
    • 2,400 W 240 VAC Tungsten.
    • 1/2 HP at 110–120 VAC.
    • 1 1/2 HP at 220–277 VAC.
    • Short circuit rating: 14 kA maximum at 277 VAC.

Control Input

  • Compatible with MACH‑ProLight ‑R and ‑U models and LI‑D outputs.
  • Class 2 circuit.
  • 350 mA momentary pulse, 24 VAC latching-type coil. Reversible polarity.
  • Color-coded red and blue screws.
  • Wiring terminal: 16–18 AWG (1.5–0.75 mm2), 1.1 Nm (10 in-lbs). Use 60°C to 75°F (140°F to 160°F) copper wire only.

Control Output

  • Allows more than 240,000 operations with 20 A load, 2,000 A inrush at 20 times minimum switch speed.
  • Wiring terminal: 10–12 AWG (6–4 mm2), 1.7 Nm (15.2 in-lb). Use 60°C to 75°C (140°F to 160°F) copper wire only.


  • Suited for indoor, stationary, non-corrosive environment with noncondensing humidity.


  • 9.6 cm W x 6 cm H x 2.5 cm D
    (3.8" W x 2.4" H x 1" D).

Ambient Limits

  • Operating: -10°C to 40°C (14°F to 104°F).


  • Snap-rail mountable with RE-WR-MP accessory.


  • UL.


Application diagram

Wiring diagram