Installation Manual
–
SDU 404
Page 4
Wiring
Follow these wiring guidelines.
24VDC Supply
Connect 24VDC to terminals 1
(positive) and 2 (0V). Connect a ground
connection to terminal 3.
Wire Requirement
SDU supply wires shall have a minimum
area of 1.0 mm
2
.
Switch Channels
Switch Channels are configurable for
loop monitoring and short circuit.
All switch channels use a two-wire
layout, where both wires from the
switch are to be routed to the SDU.
Wire Requirement
Switch wires shall have a minimum area
of 0.5 mm
2
.
Broken Wire Detection
Requirement for type approved
installations. Each switch shall have a
10k resistor connected across.
Note! The 10k resistors shall be
connected directly
at the switch
,
and not at the SDU 404.
Switches shall be normally open (NO),
and shall close to indicate engine
shutdown.
Short Circuit Detection
Each switch shall have a 10k resistor
connected in series.
Note! The 10k resistors shall be
connected directly
at the switch
,
and not at the SDU 404.
Pickup Channel
The SDU can operate with a magnetic
or active pickup source.
Connect the pickup to terminals 4 and
5, with shield to terminal 3.
Note! Make sure the cable shield is
connected at the SDU side and
not at the pickup side.
Shutdown Override
This is to be wired exactly like a Switch
Input, that is; it shall be a normally
open switch. Close the switch to
activate Shutdown Override.
Note! Make sure a 10k resistor is
connected across the switch.
