SECTION 5 – INSTALLATION
2014-MAY-08 REV. 02 PAGE 5-15
DIGITAL 3.3 VDC ALARM OUTPUT CIRCUIT LEAD
The Digital 3.3 VDC Alarm Output Circuit Lead (Yellow plug)
on the CHECKFIRE 110 Control Module is an 18 AwG, two
conductor polarity sensitive cable assembly. The white conduc-
tor is positive and the black conductor is negative.
This circuit is initiated by an alarm condition. The output is not
intended to directly operate analog devices such as audible
horns, strobes and relays. However, the installer or OEM can
use the circuit as a logic input to a vehicle operating system or
Programmable Logic Controller to manage engine shutdown,
cooling fans, hydraulic pumps, notification devices, relays, etc.
The vehicle operating system, control configuration, and field
wiring must be provided and installed by others.
Note: Removal of the yellow plug on the Alarm Output Circuit
Lead may compromise the IP67 rating for this circuit.
NOTICE
Do not remove the yellow plug unless circuit
is intended for use.
VEHICLE SYSTEM PRESSURE SWITCH
The Vehicle System Pressure Switch is a manually resettable
3-conductor SPDT switch, rated for 6A when used with volt-
ages between 12 VDC and 36 VDC nominal. The switch can
be used to perform several different tasks on system actuation,
including equipment shutdown, turning on notification appli-
ances, or providing “Pressure Switch Feedback” to a vehicle
control panel. The switch has one integral cable, sealed to the
end of the switch housing with 3-conductors (NO/C/NC) for
field connections. See Figure 5-46.
3-CONDUCTOR CABLE
Common (COM) – BLUE
Normally Closed (N.C.) – BLACK
Normally Open (N.O.) – wHITE
FIGURE 5-46
PRESSURE SWITCH CONDUCTORS
009351
CAUTION
!
The location of the Discharge Pressure Switch must be at the
expellant gas inlet port of the agent tank. Failure to comply
may result in damage to the switch and cause the switch to not
function properly.
Installation of the Vehicle System Pressure Switch is as follows
(see Figure 5-47):
1. The pressure switch installs in a standard 1/4 in. NPT
female fitting. The pressure switch must be installed in the
expellant gas line using the included 1/4 in. tee at the inlet
port of the agent tank. Use Teflon tape on the male threads.
FIGURE 5-47
INSTALLED PRESSURE SWITCH
009230
CAUTION
when threading the switch into the expellant gas line tee, DO
NOT apply torque directly to the metal switch body. Failure to
comply may result in damage to the switch. Tighten ONLY by
applying torque to the 1/4 in. NPT male pressure fitting. See
Figure 5-48.
CAUTION
DO NOT install the pressure switch in the fire hazard area or
in any area where the ambient temperature will exceed 175 °F
(79 °C). Failure to comply may prevent the pressure switch from
functioning properly.
NO wRENCH
TORqUE
wRENCH
GRIP
FIGURE 5-48
WRENCH GRIP AREA
009231
CHECKFIRE 110
Detection and Actuation System
PRESSURE
SwITCH
1/4 IN.
TEE
RELEASE
CIRCUIT
EXPELLANT
GAS LINE
TO VEHICLE
CONNECTION
