Functional Devices RIB2421SB : Enclosed Power Relay, 20 Amp Contact Rating, Relay Contact Type: SPST-N/O + Override, 24 Vac/dc/208-277 Vac/120 Vac Coil, NEMA 1 Housing

The RIB2421SB is widely used in HVAC, lighting, and motor control applications where override functionality is required. With compatibility across 24 Vac/dc, 120 Vac, and 208–277 Vac coil voltages, this relay integrates easily into both low- and high-voltage systems. The manual override switch is useful for service work or testing without requiring control input. This relay’s durable NEMA 1 enclosure and UL certifications make it suitable for commercial building automation projects.

• Relays & Contact Type: One (1) SPST Continuous Duty Coil
• Expected Relay Life: 10 million cycles minimum mechanical
• Operating Temperature: -30 to 140° F
• Humidity Range: 5 to 95% (noncondensing)
• Operate Time: 18ms
• Relay Status: LED On = Activated
• Dimensions: 2.30" x 3.20" x 1.80" with 0.50" NPT Nipple
• Wires: 16", 600V Rated
• Approvals: UL Listed, UL916, UL864, C-UL, California State Fire Marshal, CE, RoHS
• Housing Rating: UL Accepted for Use in Plenum, NEMA 1
• Gold Flash: No
• Override Switch: Yes

• 20 Amp Resistive @ 277 Vac
• 20 Amp Ballast @ 277 Vac (N/O)
• 10 Amp Ballast @ 277 Vac (N/C)
• Not rated for Electronic Ballast
• 10 Amp Tungsten @ 120 Vac (N/O)
• 770 VA Pilot Duty @ 120 Vac
• 1,110 VA Pilot Duty @ 277 Vac
• 2 HP @ 277 Vac
• 1 HP @ 120 Vac

Coil Voltage Input:
24 Vac/dc ; 208–277 Vac ; 120 Vac ; 50–60 Hz
Drop Out = 2.1 Vac / 3.8 Vdc
Pull In = 18 Vac / 22 Vdc

Coil Current:
83 mA @ 24 Vac
47 mA @ 120 Vac
69 mA @ 208–277 Vac
47 mA @ 30 Vdc