J.P. Instruments Slim Line Gauges Installation Guide - Manual (Page 7)

INSTALLING THE SLIM LINE® INSTRUMENT SERIES PAGE 7 OF 14
REV B
SIDE VIEW
SIDE VIEW
SIDE VIEW
gray
wire
+12/24
Remote Alarm Light
(150 ma max)
Slim Line automatically accommodates both 14 and 28 volt electrical systems. Connect the power lead (red) to
a separate 2 amp circuit breaker (or 1 amp in-line fuse) connected to the avionics power bus. The avionics
master switch will then be used to turn off the instrument during engine start-up. If the panel lacks an avionics
master switch it is recommended that one be installed or a circuit breaker switch be provided to turn off the
Slim Line during engine start-up. Connect the ground return (black) to the avionics ground.
No connection to the aircraft dimmer system is required or permitted because the instrument dims automatically
with reductions in ambient light.
The gray remote alarm wire is an open collector capable of
sinking up to 150 ma. This signal may be connected to a
unique alarm light or buzzer, or it may be connected to
other Slim Line instruments in a “wired-OR” configuration
to a common alarm light or buzzer. If it is not used, leave
the line open and tie-wrap the wire so that it does not
obstruct the freedom of control travel.
Plug the probe or sensor connector on the rear of the
instrument with the hook tab of the connector pointing
down. Be sure the connector is aligned with all the pins and
not shifted left or right.
The Volt/Amp instrument is configured without a
connector. Identify the wire bundle with the toggle switch
attached. The toggle switch should be mounted to the instrument panel near the instrument. The white wire
should be connected to the positive side of the shunt and the gray wire to the negative side of the shunt. See the
section, later, on VOLT/AMP shunt wiring.
17) Routing the Wiring
Leave adequate service loops at the instrument. Bundle all the probe and sensor wires together and route the
them from the instrument through the firewall using fireproof rubber grommets and flame retarding silicone.
Use an existing hole if possible. All wires must be routed away from high temperature areas (exhaust stacks,
turbochargers, etc.). Secure probe and sensor leads to a convenient location on the engine approximately 8 to 12
inches from the probe or sensor, being sure there is sufficient slack to absorb engine vibration and torque. It is
essential in routing the probe or sensor wire that this wire not be allowed to touch metal parts of the air-frame or
engine since abrasion will destroy the wire.
18) Temperature Probe Wiring
When cutting the pair of leads to the proper length to connect to the probes, leave enough slack in the wiring so
that probe may be interchanged to an adjacent cylinder if necessary for trouble-shooting and servicing.
Thermocouple wire length is not critical and should be trimmed to any length as required for a clean
installation.
The Temperature probe must be wired with the correct polarity. The temperature probe connects to its
temperature indicator with yellow jacket Teflon Chromel Alumel wire supplied. Strip the wires as shown below
-observing color codes.
1/4" 1 1/2"
Fold back wire
double before
crimping terminals
2 1/4"
Thermocouple wire harness
red
yellow