J.P. Instruments Classic Scanner - Manual (Page 3)

INSTALLING THE EGT SCANNER
Page 3 of 3
Rev-D
NOTE:
Most factory installed cylinder head temperature gauges utilize a bayonet or threaded resistive
type probe that occupies one of the bayonet sockets. This probe is not compatible with the
thermocouple probes required for the SCANNER.
4) Spark Plug Gasket CHT Probe
The spark plug gasket probe, PIN M-113, replaces the standard copper spark plug gasket on
one spark plug in each cylinder. The plug chosen should be the one that receives the most
direct cooling air for all Lycoming engines or top plug and the one that receives the least air or
bottom plug for Continental engines. The plug gasket should be removed and replaced by the
gasket probe. After many removals the probe may be annealed for re-use. Heat and quench in
water.
5) Oil Temperature Probe
The Oil Temperature Probe PIN 400505-C,-L is installed as a supplemental oil temperature
indicator. The -L part number is for all Lycoming Direct Drive Engines and is installed in tile
Right (passenger side) front Oil galley by removing the present 1/8 NPT plug (see fig-6). The -C
part number is for all Continental Direct Drive engines and is installed in the Left (pilot side) front
Oil galley by removing the present 3/8 NPT plug (see fig-7). Oil temperature will be displayed on
probe #7 for six cylinder engines and probe #5 for four cylinder engines. Instruments with CHT
option will display oil temperature on the CHT channel. The original oil temperature gauge and
sensor must remain operative. Check for oil leaks before first flight.
6) Outside Air Temperature Probe, OAT
The OAT probe, PIN 400510, is very similar to the conventional mechanical probe: now in use
in many aircraft and will fit into the same hole. If no hole exist, a 5/16 hole will be required. It is
recommended to place the probe in the airframe away from engine exhaust heat. If placed in
sheet metal panel, a 2 inch square backing plate may be required for support. The outside
aluminum tube is used to both hold the probe in place and shield it from radiated heat. The OAT
probe is connected to EGT channel #7 or #5
for SCANNERS without TIT option. With TIT option on EGT channel #8 or #6.
7) Wiring (12 I 24 volt)
The EGT SCANNER will function on both 14 and 28 volt electrical systems. The SCANNER red
lead is connected to the positive avionics buss through a circuit breaker of 3 amps or an in-line
fuse of 1 amp. The black lead should grounded to the engine for accuracy. The EGT
SCANNER does not require a separate switch, but one can be installed. No connection to the
aircraft dimmer system is required because the instrument has its own dimming switch (See fig
8 to 12) for wiring details).