© 2016 Littelfuse Protection Relays & Controls

Flashers and Tower Lighting Controls

Tower and Obstruction Lighting Controls

www.littelfuse.com/scr9L

Rev: 1-A-062316

Wiring Diagram

SCR9L

Universal Lamp Alarm Relay

Description

The SCR9L is a universal lamp alarm relay designed to sense the

failure of flashing or steady LED beacon lamps or obstruction

lamps. The SCR9L energizes when one or more lamps fail. It

will monitor the operation of one to eight beacon or obstruction

lamps. All monitored lamps must be the same wattage and

voltage. When connected to a site monitoring system, it

provides the remote lamp monitoring protection required by the

FAA-AC No: 150/5345-43E.

Operation

When a lamp fails, the SCR9L senses a decrease in current flow.

After a 10s trip delay, the onboard LED glows and the two alarm

outputs energize. The outputs and the LED are reset when the

failed lamps are replaced and the unit is recalibrated. The SCR9L

will sense an open flasher, it will not sense a continuously ON

flasher (see FB Series). Removing input voltage de-energizes the

output and the LED‘s. It does not change the calibration.

Features & Benefits

FEATURES

BENEFITS

Self calibrating

Designed for use with all types of LED beacon and

obstruction lamps

Failsafe beacon

monitoring

Relay will also provide an alarm signal on a failed

flasher (open)

Number of lamps

monitored is switch

selectable up to 8

User selection allows quick set up and easy

adaption to multiple applications

Universal voltage

120 to 230VAC

Designed for use in most applications

Isolated, 10A, SPDT

alarm output contacts

Provides remote beacon monitoring when

connected to a site monitoring system, as is

required by the FAA

LED indication

Provides visual relay status of operation, alarm, trip

delay, and calibration

Fully encapsulated

Protects against shock, vibration, and humidity

Accessories

C103PM (AL) DIN Rail

35 mm aluminum DIN rail available in a 36 in.

(91.4 cm) length.

P1023-20 DIN Rail Adapter

Allows module to be mounted on a 35 mm DIN

type rail with two #10 screws.

L1 N/L2

L1 N/L2

BEACON LAMP CONNECTION DIAGRAM

OBSTRUCTION LAMP

CONNECTION DIAGRAM

V = Voltage

B = Beacon Lamps

SS = Selector Switch

L = LED Indicator

F = Flasher

AXL = Auxiliary

Load/Alarm

OL = Obstruction Lamps

SI = Sensor Input

H = “3“ Spare AC Hot

Connection (2A max.)