The Functional Devices RIBU1C is a 10-amp SPDT pilot control relay in a NEMA 1 housing, designed for general HVAC and building automation applications. The standard version for commercial HVAC and BAS applications. Accepted for use in plenum spaces. It accepts two independent coil voltage inputs — 10-30 VAC/DC on the white/blue leads and 120VAC on the white/black leads — covering virtually every HVAC control voltage without stocking multiple coil variants. Gold flash contacts ensure reliable signal-level switching, and the relay carries Functional Devices' 10-year warranty with a rated mechanical life of 10 million cycles minimum.
Best for: General hvac and building automation applications requiring a 10-amp SPDT pilot relay with dual coil voltage flexibility and NEMA 1 rated housing.
The RIBU1C is backed by Functional Devices' industry-leading 10-year warranty — the longest standard warranty in the RIB product line. Functional Devices reports a field failure rate of approximately 1 in 16,000 units.
The Standard for Commercial HVAC Pilot Control
The RIBU1C is the most widely stocked and specified pilot relay in commercial HVAC. Its dual coil voltage input — 10-30 VAC/DC on the white/blue leads and 120VAC on the white/black leads — means one part number covers virtually every control voltage found in a commercial building automation panel. Gold flash contacts ensure reliable signal switching at low current levels, and the NEMA 1 housing is accepted for use in plenum spaces, making it suitable for fan coil unit and VAV box installations without requiring a separate enclosure.
RIBU1C
Standard grey NEMA 1 housing. UL Listed, UL916. Plenum accepted. The most widely specified version for commercial HVAC and BAS applications.
RIBU1C-RD
Red enclosure. UL864 and California State Fire Marshal listed. Required for fire alarm and smoke control circuit applications.
RIBU1C-N4
NEMA 4 enclosure for wet, outdoor, and wash-down locations. UL508 listed for industrial control equipment.
| Wire Color | Function | Notes |
|---|---|---|
| White / Black stripe | 120VAC Coil Input | Use for 120VAC control circuits. Cap white/blue leads when using this input. |
| White / Blue stripe | 10-30 VAC/DC Coil Input | Use for 24VAC BAS outputs or 10-30VDC signals. Cap white/black leads when using this input. |
| White / Yellow stripe | Common (Comm) | Common terminal for SPDT contact circuit |
| Blue | N/C — Normally Closed | Connected to Common when coil is de-energized |
| Yellow | C — Contact | Switching contact output |
| Orange | N/O — Normally Open | Connected to Common when coil is energized |
| Specification | Value |
|---|---|
| Part Number | RIBU1C |
| Contact Configuration | SPDT (Single Pole Double Throw) — 1 Relay, Continuous Duty Coil |
| Coil Voltage Input | 10-30 VAC/DC and 120VAC (dual input, 50-60 Hz) |
| Pull In Voltage | 9 VAC / 10 VDC |
| Drop Out Voltage | 2.1 VAC / 2.8 VDC |
| Coil Current — 10 VAC | 33 mA |
| Coil Current — 24 VAC | 46 mA |
| Coil Current — 120 VAC | 28 mA |
| Contact Rating — Resistive | 10A @ 277VAC | 10A @ 28VDC |
| Contact Rating — Pilot Duty | 480 VA @ 240-277VAC | 480 VA Ballast @ 277VAC |
| Contact Rating — Tungsten | 600W @ 120VAC N/O | 240W @ 120VAC N/C |
| Contact Rating — Motor | 1/3 HP @ 120-240VAC N/O | 1/6 HP @ 120-240VAC N/C | 1/4 HP @ 277VAC N/O | 1/8 HP @ 277VAC N/C |
| Electronic Ballast | Not rated for electronic ballast |
| Operate Time | 20ms |
| Expected Relay Life | 10 million cycles minimum (mechanical) |
| Gold Flash Contacts | Yes |
| Status LED | Yes — On = Relay Activated |
| Override Switch | No |
| Housing Rating | NEMA 1, Accepted for Use in Plenum |
| Enclosure Color | Grey |
| Conduit Hub | 0.50” NPT |
| Dimensions | 1.70”H x 2.80”W x 1.50”D |
| Lead Wires | 16”, 600V rated |
| Operating Temperature | -30 to 140°F |
| Humidity Range | 5 to 95% non-condensing |
| Approvals | UL Listed, UL916, C-UL, CE, RoHS |
| Origin | Made of US and non-US parts |
| Warranty | 10 Years |
| Bulk Ordering | Add -10PACK, -25PACK, or -100PACK to part number |
BAS Binary Output Switching
Interfaces building automation system 24VAC or 24VDC binary outputs to 120V or line-voltage HVAC equipment
Fan Coil Unit Control
Switches fan and valve outputs in FCU applications from low-voltage controller outputs to line-voltage equipment
Rooftop Unit Interlock
Pilot duty rated for starter coils and contactor coils in RTU applications requiring isolated switching
Lighting Control
480VA ballast pilot duty rating suitable for energizing lighting contactors from low-voltage control signals
VAV Box Control
Plenum-rated housing allows direct installation in VAV terminal box control applications without separate enclosure
General HVAC Panel Switching
Compact footprint and dual coil voltage make this the go-to stock relay for mixed-voltage HVAC control panels
Important — Electronic Ballast Rating & Coil Input Selection
The RIBU1C is not rated for electronic ballast loads. Use for standard magnetic ballast and pilot duty rated loads only. When wiring the coil, use only one coil input at a time — either the 10-30 VAC/DC leads (white/blue) or the 120VAC leads (white/black). Cap off the unused leads. Never energize both coil inputs simultaneously.
- Mounting:
- Enclosed
- Number of Relays:
- 1
- Relay Contact Type:
- SPDT
