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The FB series is a universal lamp alarm relay designed to sense the failure of flashing LED beacon lamps. It will monitor the operation of one to eight beacons connected to a single flasher and/or auxiliary modules and the operation of the flasher.

SSAC FB9L Universal Lamp Alarm Relays Distributors

FB9L Series

The FB Series output relay energizes when one or more lamps fail. All monitored lamps must be the same wattage and voltage. The 0.5A solid-state output energizes when a flasher failure is sensed.

When a LED beacon lamp fails, the FB senses a decrease in current flow. After a 10s lamp failure trip delay, the isolated SPDT (4-5-6) and non-isolated SPNO (3-1) relay contacts energize. These contacts are used to indicate a beacon failure has occurred. The "L" onboard LED indicator flashes green during the trip delay and glows red after the output relay energizes. Connected to a site monitoring system, it provides remote beacon monitoring required by FAA-AC No: 150/5345-43E.

If you are looking for SSAC Flashers, please call us on (800) 894 - 0412 or email us at we will do our best to help you find the SymCom FB120A incandescent beacon alarm relay that you are looking for at the most competitive prices possible. If you are searching for SSAC FB230A incandescent beacon alarm relays technical information (data-sheets) please use the datasheets or product selection guide page links.

The FB also monitors the operation of the flasher. If the flasher remains in the ON or OFF condition for more than 6s the solid-state output energizes and the "F" flasher failure, onboard LED glows red. This output is normally used to energize an external flasher bypass relay. The contacts of the bypass relay are used to route voltage around the failed flasher and to indicate an alarm condition.

Note: In a single flasher, single beacon system, if the beacon lamp fails, zero current flow is detected. This will cause the flasher failure output to energize after 6s and then the beacon failure outputs after 10s. This is normal operation and can be expected anytime zero current is flowing through the monitored conductor.


The alarm relays must be calibrated after initial installation and each time the LED lamps are replaced. In order to calibrate or re-calibrate the alarm relay, the internal memory must be cleared.

Remove input voltage, transfer the calibration switch to the off position, re-apply input voltage. The LED will flash Red to indicate the memory is clear and the relay is ready for calibration.


  • Senses failed flashing beacon lamps
  • Switch selectable number of beacons
  • Senses flasher failure
  • Isolated, 10A, SPDT alarm output contacts
  • 10A, NO line voltage alarm output
  • 0.5A, solid-state flasher failure output "F"
  • Self calibrating; no fine adjustment required
  • Meets FAA-AC No: 150/5345-43E

Our industrial factory automation supplies distributors warehouse in Boise, Idaho USA stocks some SymCom products enabling us to further assist you in finding the correct SSAC FB120A flashers in the USA, Canada and Mexico. Whether we have ABB FB230A flashers in stock in Boise, Idaho USA or need to ship direct from Littelfuse to any USA cities; Clearwater Tech can get SSAC FB120A flasher to you fast and save you some money! It will be very helpful if you have the ABB FB230A flasher part numbers ready, then our sales representatives can provide you with a pricing and availability quote for SymCom FB230A incandescent beacon alarm relay that you are looking for in seconds. If you do not have the part numbers for SSAC FB120A incandescent beacon alarm relays, our application engineers will be able to help you figure out the part numbers and get the price quote to you as soon as possible.

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