FB9L Series - Universal Lamp Alarm Relay

Series: FB9L
Questions? Contact Littelfuse Support
External overview image
Roll Over to Zoom
Disclaimer Notice

Littelfuse products are not designed for, and shall not be used for, any purpose (including, without limitation, automotive, military, aerospace, medical, life-saving, life-sustaining or nuclear facility applications, devices intended for surgical implant into the body, or any other application in which the failure or lack of desired operation of the product may result in personal injury, death, or property damage) other than those expressly set forth in applicable Littelfuse product documentation. Warranties granted by Littelfuse shall be deemed void for products used for any purpose not expressly set forth in applicable Littelfuse documentation. Littelfuse shall not be liable for any claims or damages arising out of products used in applications not expressly intended by Littelfuse as set forth in applicable Littelfuse documentation. The sale and use of Littelfuse products is subject to Littelfuse Terms and Conditions of Sale, unless otherwise agreed by Littelfuse. "Littelfuse" includes Littelfuse, Inc., and all of its affiliate entities.

The FB9L 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. The FB9L 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.

Operation
When a LED beacon lamp fails, the FB9L 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.

The FB9L also monitors the operation of the flasher. If the flasher remains in the ON or OFF condition for more than 6s the solidstate 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.

For Technical Questions

Call +1 800-832-3873 or email us at relays@littelfuse.com 

Access specifications, certifications, check availability and order parts below

Catalog #Input
Voltage (V)		Output
Form		Trip Delay RangeOutput Load Rating (VA)DimensionsStockSamples
FB9L120 - 230 V ac3 total: 2 relay and 1 solid stateFlasher failure: Fixed at 6 s; -0/+40; Lamp failure: Fixed at 10 s; -0/+40%One isolated SPNO relay rated 5 A @ 240 Vac or 30 Vdc resistive - 1/4 hp @125 Vac - 1/2hp @ 250 Vac; One SPDT relay rated at 10 A @ 240 Vac or 30 Vdc resistive - 1/4 hp @125 Vac - 1/2 hp @ 250 Vac; One solid-state line voltage output rated 0.5 A steady and 5A inrush3 H x 2 W in. (76.7 x 51.3 mm)CheckOrder
To request product environmental information, please complete the Product Environmental Information Request Form.