Wiring; Egt And Cht Probe Wiring - JPI EGT-701 Installation Manual

FAA APPROVED INSTALLATION MANUAL FOR THE EGT-701 Report 103
INSTALLING THE EGT-701 SCANNER® 1/20/09 Rev-E Page 9 of 30
There must be flexible hose into and out of the fuel flow transducer. The hoses must meet TSO-C53a type C or D FAA
specification. The new hoses must be the same size as the current hose in the aircraft. The fuel flow transducer must
be wrapped with fire sleeving. Cut a 1 inch slit in the center of the fire sleeve and pass the transducer connector and
cable through it. Seal with high temperature silicone RTV sealant.
The placard "Do not rely on fuel flow instrument to determine fuel levels in tanks" must be mounted on the
aircraft instrument panel near the EGT-701. If the aircraft is equipped with a primary fuel flow instrument, the following
placard must be mounted on the aircraft instrument panel near the EGT-701 "Refer to original fuel flow
instrumentation for primary information."
11) WIRING (12 / 24 volt)
The EGT-701 automatically accommodates both 14 and 28 volt electrical systems. Connect the power lead (red) to a
separate 5 amp circuit breaker (or 2 amp slow blow in-line fuse) connected to the avionics power buss. The avionics
master switch will then be used to turn off the instrument during engine start-up. The EDM-700 has a 10-second
warm-up. If the panel lacks an avionics master switch we recommend that one be installed or a circuit breaker switch
be provided to turn off the EGT-701 during engine start-up. If the voltage fall below 9.8 vdc the instrument will turn off
automatically. The Instrument should be grounded at the engine. No connection to the aircraft dimmer system is
required because the instrument dims automatically with reductions in ambient light.
12)

EGT and CHT Probe Wiring

The EGT-701 is supplied with special Teflon insulated Chromel Alumel factory assembled wiring harness configured
for the correct number of cylinders. The wire harness is marked E-1= EGT-1, C-1= CHT-1, etc. TIT is marked "T",
Oil I = "O" and OAT = "A". For retrofits of the EGT-100 SCANNER or bar graph instruments, where only the
indicators are being exchanged, the old harness wires need to be pinned with AMP P/N 665049 and fitted into AMP
D-SUB connector P/N 205207-1 with hood per drawing 300701 fig-6 or connected directly via an adapter connector.
NOTE: Unlike most other EGT & CHT installations the probe wire length is not critical and should be trimmed to any
length as required for a clean installation.
The Temperature probes must be wired with the correct polarity. Each wire is marked with the cylinder number. The
EGT and CHT probes connect to the temperature indicator with yellow jacket Teflon Chromel Alumel wire supplied.
Strip the wires according to drawing 5057 and terminate with the crimp-on ring terminals provided. Verify the quality of
each crimp with a sharp pull on the wire. The terminal should be almost impossible to pull off when crimped correctly.
With in a few inches of the instrument terminal strip a connector may be installed.
NOTE: The ring terminals may be crimped with a "service type" tool, however AMP part number 48518 tool is
recommended. Be sure to test each crimp by pulling on the wire to assure it will not come out.
The most common installation problems are poor quality terminations.
The EGT-701 must be grounded to the engine block, not at a ground point under the instrument panel. No
connection to the aircraft dimmer system is required or permitted because the instrument dims automatically with
reductions in ambient light.
Install the data port connector in the instrument panel. This is the 2.5 mm ID, 5.5 mm OD on the
twisted white and black wires on J1. See Installing the Instrument section earlier in this manual.