Service manual

6-- 21
T--318
Sensor
40 mm (1 1/2 inch)
6.3 mm (1/4 inch)
Mounting Stud Type
Sensor
40 mm (1-1/2 inches)
6.3 mm (1/4 inch)
Bulb Type
Figure 6-27 Sensor Types
d. Prepare the cables by cutting wires to the opposite of
the sensor (See Figure 6-28).
When installing a single wire color two wire sensor ,
cut one wire of existing two wire cable 40 mm (1-1/2
inch) shorter than the other wire.
When replacing two single sensors with a combina-
tion (3-wire) sensor , the black wires of the cables
should be cut to the same length and the red wire of
one cable cut to the shorter length.
When replacing a original 3-wire sensor, cut the black
wire to the middle length and the red wire to the short-
er length.
e. Strip back insulation on all wiring 6.3 mm (1/4 inch).
f. Slide a large piece of heat shrink tubing over the
cable, and place small pieces of heat shrink tubing,
one over each wire, before adding crimp fittings as
shown in Figure 6-28.
g. If required, slide the cap and grommet assembly onto
the replacement sensor. If the replacement sensor is
of a larger diameter than the original, a different grom-
met may be required.
h. Slip crimp fittings over dressed wires (keeping wire
colors together). Make sure wires are pushed into
crimp fittings as far as possible and crimp with crimp-
ing tool.
i. Solder spliced wires with a 60% tin and 40% lead
Rosincore solder.
j. Slide heat shrink tubing over splice so that ends of
tubing cover both ends of crimp as shown in
Figure 6-28.
k. Heat tubing to shrink over splice. Make sure all seams
are sealed tightly against the wiring to prevent mois-
ture seepage.
l. Slide large heat shrink tubing over both splices and
shrink.
CAUTION
Do not allow moisture to enter wire splice
area as this may affect the sensor resis-
tance.
m. Reinstall sensor, refer to paragraph 6.22.3.
NOTE
The P5 Pre-T rip test must be run to inactivate
probe alarms (refer to paragraph 4.8).
6.22.3 Sensor Re-Installation
a. Sensors STS/SRS
To properly position a supply sensor, the sensor must be
fully inserted into the probe holder. This positioning will
give the sensor the optimum amount of exposure to the
supply air stream, and will allow the Controller to
operate correctly. Insufficient probe insertion into the
probe holder will result in poor temperature control due
to the lack of air flow over the sensor.
It is also necessary to ensure that the probe tip does not
contact the evaporator back panel. The design
minimum clearance of 6 mm (1/4 inch) should be
maintained (see Figure 6-29).
b. Sensor RTS/RRS
Reinstall the return sensor as shown in Figure 6-30. For
proper placement of the return sensor , be sure to
position the seal section of the sensor against the the
side of the mounting clamp.
c. Sensor DTS
The DTS sensor must have insulating material placed
completely over the sensor to insure the coil metal
temperature is sensed.
Sensor (Typical)
Cable
Heat Shrink
T ubing
Large Heat Shrink
T ubing
REPLACEMENT 2 WIRE TO
2WIREOR3WIRETO3WIRE
REPLACEMENT FO R DUAL SINGLE
SENSOR CONFIGURATION
RED
BLACK
RED/WHITE
Figure 6-28 Sensor and Cable Splice