Carrier 69NT40-511-199 - Manual (Page 118)

6-24 T-268-07
position the enlarged positioning section of the
sensor against the the side of the mounting clamp.
NOTE
The P5 Pre-Trip test must be run to inactivate
the alarm (refer to section 3.2.1).
Evaporator Grille
Return Sensor
Mounting Clamp
Enlarged Positioning
(Plastic) Section
Figure 6-24. Return Sensor Positioning
6.23.4 Checking Sensor (AMBS or DTS)
a. Turn unit OFF and disconnect power supply.
b. Refer to section 6.27 for removal of the Controller
module.
AMBS or DTS:
Using the plug connector marked “EC” that is
connected to the Controller module. Locate the wires
marked AMBS or DTS, depending on which sensor
needs to be replaced. Follow that wire to the connector
and using the pins of the plug, measure the ohms
resistance. Readings are shown in Table 6-1.
6.23.5 Replacing Sensor (AMBS or DTS)
a. Turn unit power OFF and disconnect power supply.
b. Cut wires to 25.4 cm (10 inches) from the back of
the mounting stud of the defective sensor and
discard.
c. Cut one of the two wires from step b 25.4 mm (1.0
inch) shorter than the other wire.
d. Cut one replacement sensor wire back 25.4 mm (1.0
inch). (See Figure 6-25.)
e. Strip back insulation on all wiring 6.35mm (1/4
inch).
Sensor
25.4 mm (1.0 inch)
6.35mm (1/4 inch)
Mounting Stud
Figure 6-25. Sensor (AMBS or DTS)
f. Slide two small pieces of heat shrink tubing over
each wire before adding crimp fittings as shown in
Figure 6-26.
g. Slip crimp fittings over dressed wires. Make sure
wires are pushed into crimp fittings as far as
possible and crimp with crimping tool.
h. Solder spliced wires with a 60% tin and 40% lead
Rosincore solder.
i. Slide heat shrink tubing over splice so that both
ends of tubing cover both ends of crimp as shown in
Figure 6-26.
Sensor
Heat Shrink
Tubing (2) Crimp Fitting
Crimp Fitting
Figure 6-26. Sensor and Wire Assembly
(AMBS or DTS)
j. Heat tubing, preferably with a flameless heat gun. If
not available, a propane torch will work (caution
should be taken not to burn the heat shrink tubing or
wire insulation). Make sure all seams are sealed
tightly against the wiring to prevent moisture
seepage.
CAUTION
Do not allow moisture to enter wire splice
area as this may affect the sensor resistance.
k. Secure sensor to unit and check sensor resistance as
detailed in section 6.23.4.
NOTE
The DTS sensor must have “Presstite”
insulating material placed completely over the
sensor to insure proper function of the sensor.