3 .1
Power supply connections
Mains power connections (240VAC or 110VAC) are made via a plug in terminal with screw
connections.
The transformer low voltage AC output goes to the power supply connector P1 on the main circuit
board via the lead supplied.
Non isolated DC supplies (15 to 24V) are connected at the main circuit board power supply
connector P1 via the plug in connector terminals. The positive and negative supplies may be connected
either way around.
Optional isolated DC supplies use plug in terminals supplied on the power supply board as shown
below. The output from the isolated DC supply board connects directly to the main circuit board power supply
connector via the plug in connector (P1) terminals.
3 .2
Relay connections
The LD4 is supplied with two alarm relays as standard with connections on P6. The relays are single
pole, single throw types and are rated at 5A, 240VAC into a resistive load. The relay contact is voltage free
and may be programmed for normally open or normally closed operation.
Page 6 of 46
LD4LNMAN-1.0-1
AC MAINS
E N A
A
C
OUT
LARGE DIGIT POWER SUPPLY
SERIAL NO.
TRANSFORMER
SOCKET FOR 240/110V
PLUG IN MAINS
CONNECTOR
TRANSFORMER
AC OUTPUT
SOCKET
DC INPUT
E
-
+
DC OUT
LARGE DIGIT POWER SUPPLY
SERIAL NO.
DC TO DC
CONVERTER
(ISOLATING)
SOCKET FOR DC
INPUT CONNECTOR
SOCKET FOR DC
OUTPUT CONNECTOR
FOR DC SUPPLY TO
LD4 INPUT CIRCUIT BOARD
-
+
OPTIONAL ISOLATED DC BOARD
