© 2016 Littelfuse Protection Relays & Controls

Flashers and Tower Lighting Controls

Tower and Obstruction Lighting Controls

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Rev: 1-A-062316

Wiring Diagram

SCR SERIES

Universal Lamp Alarm Relay

Description

The SCR series is a universal lamp alarm relay designed to

sense the failure of flashing or steady incandescent beacon

lamps or steady side lights. The toroidal current sensor provides

isolation and allows monitoring of more than one line at a time.

The SCR Series energizes when one or more lamps fail. It will

monitor the operation of one to four side lights and up to four

beacon lamps.

Operation

When a lamp fails, the SCR Series senses a decrease in current

flow. After a fixed time delay, the LED glows and the two alarm

outputs energize. The outputs and the LED are reset when

the failed lamps are replaced and the current returns to the

nominal setting, or when the input voltage is removed. The SCR

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

flasher (see FB Series).

Features & Benefits

FEATURES

BENEFITS

Toroidal current sensing

Provides isolation from the lighting circuit and

allows monitoring of multiple lines simultaneously

Monitors 1-4 side

lights or up to 4

beacon lamps

Senses failed incandescent flashing beacon or

steady obstruction lamps

Isolated, 10A, SPDT alarm

output plus one 1A,

solid-state line voltage

alarm output

Provides alarm indication and can also be used for

remote monitoring of the lighting system

Fixed trip delay (6s)

Prevents nuisance alarms

Switch selectable

number, voltage, and

wattage of lamps

User selectable to meet wide application needs

with one relay

(SCR430T only)

L1 N/L2

L1

N/L2

BEACON LAMP CONNECTION DIAGRAM

OBSTRUCTION LAMP CONNECTION DIAGRAM

V = Voltage

B = Beacon Lamps

SS = Selector Switch

T =Toroid

F = Flasher

AXL = Auxiliary

Load/Alarm

Relay contacts

are isolated.

V = Voltage

SS = Selector Switch

T =Toroid

AXL = Auxiliary

Load/Alarm

OL = Obstruction

Lamps

Relay contacts

are isolated.

Ordering Information

MODEL

INPUT

LAMP TYPE

SCR430T

120VAC

Incandescent

SCR630T

230VAC

Incandescent

If you don’t find the part you need, call us for a custom product 800-843-8848