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AHU Fan Safety Alarm Circuit, 24 VAC/DC, 4 Alarm Inputs with N/C Outputs, NEMA 1
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AHU Fan Safety Alarm Circuit, 24 VAC/DC, 4 Alarm Inputs with N/C Outputs, NEMA 1

AHU Fan Safety Alarm Circuit, 24 VAC/DC, 4 Alarm Inputs with N/C Outputs, NEMA 1
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$103.13 each
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AHU Fan Safety Alarm and General Purpose Logic Circuit, 24 Vac/dc Power Input, 4 Alarm Inputs all with N/C Outputs, NEMA 1 Housing

RIBLB-4 is simply a device that combines a common relay-logic function into a small, easy-to-install, and less expensive form. A master relay will open if any one of the normally-closed (N/C) inputs open. There are four inputs. LED status of all inputs, the master relay, and power input is provided. Bypass of un-used inputs is also provided. The RIBMNLB series is provided with mounting track for mounting in user-provided electrical enclosures. The RIBLB series is enclosed in a NEMA-1, 4" x 7" enclosure with a clear lid to allow viewing of the status LEDs. The master relay has three general-purpose outputs: two 24 V output terminals and one dry-contact output rated up to 10 Amp @ 277 Vac (terminals on RIBMNLB series, wires on RIBLB series.) The most common application is an Air Handling Unit (AHU) fan-safety-shutdown where the master relay is used to shutdown the fan. Contact closure outputs are provided so that a DDC controller can determine the cause of a shutdown. Specifications:
  • RIBLB-4 have four Alarm Inputs and one Master Alarm.
  • Expected Relay Life: 10 million cycles minimum mechanical
  • Operating Temperature: -30 to 140 F
  • Humidity Range: 5 to 95% (noncondensing)
  • Operate Time: 8ms
  • Power Input: 4 Amp max. @ 24 Vac/dc ; 50-60 Hz
  • Alarm Status: LED On = Activated
  • Dimensions: 4.28" x 7.00" x 2.00" with .75" NPT Nipple (RIBLB-6/-4/-2)
  • Track Mount: MT212-6 Mounting Track Provided (RIBMNLB-6) MT212-4 Mounting Track Provided (RIBMNLB-4, RIBMNLB-2)
  • Approvals: UL Listed, UL916, UL864, C-UL, CE, RoHS, CSFM
  • Housing Rating: UL Listed, NEMA 1, C-UL, CE Approved, UL Accepted for Use in Plenum
  • Gold Flash: No
  • Override Switch: No


Product Type:

Safety Relay



Humidity Range:

5% to 95% Relative Humidity (Non-Condensing)

Operating Temp Range:

-30º to 140ºF


4 Alarm Inputs

1 Master Alarm

Enclosure Type:


NEMA Rating:


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