6--22
T-334
Table 6--3 Sensor Temperature/Resistance Chart
(+/-.002%)
Temperature
Resistance
C
F
(Ohms)
AMBS, CPSS,
DTS, RTS, RRS,
STS, SRS
CPDS
-30
-22
177,000
1,770,000
-25
-13
130,400
1,340,000
-20
-4
97,070
970,700
-15
5
72,900
729,000
-10
14
55,330
553,000
-5
23
43,200
423,300
0
32
32,650
326,500
5
41
25,390
253,900
10
50
19,900
199,000
15
59
15,700
157,100
20
68
12,490
124,900
25
77
10,000
100,000
30
86
8,060
80,600
35
95
6,530
65,300
40
104
5,330
53,300
45
113
4,370
43,700
50
122
3,600
36,000
55
131
2,900
29,000
60
140
2,490
24,900
65
149
2,080
20,800
65
158
1,750
17,500
e. Using the plug connector marked “EC” that is con-
nected to the back of the controller, locate the sensor
wires (RRS, RTS, SRS, STS, AMBS, DTS, CPDS
OR CPSS as required). Follow those wires to the con-
nector and using the pins of the plug, measure the
resistance. Values are provided in Table 6--3.
Due to the variations and inaccuracies in ohmmeters,
thermometers or other test equipment, a reading
within 2% of the chart value would indicate a good
sensor. If a sensor is defective, the resistance read-
ing will usually be much higher or lower than the resis-
tance values given.
6.22.2 Sensor Replacement
a. Turn unit power OFF and disconnect power supply.
b. Cut cable 5 cm (2 inches) from shoulder of defective
sensor and discard the defective probe only. Slide the
cap and grommet off a bulb type sensor and save for
reuse.
Do not cut the grommet.
c. Cut one wire of existing cable 40 mm (1-1/2 inches)
shorter than the other wire.
d. Cut one replacement sensor wire (opposite color)
back 40 mm (1-1/2 inches). (See Figure 6--20.)
e. Strip back insulation on all wiring 6.3 mm (1/4 inch).
1
2
Mounting Stud Type
3
Bulb Type
1
2
3
1. Sensor
2. 40 mm (1 1/2 in.)
3. 6.3 mm (1/4 in.)
Figure 6--20 Sensor Types
f. Slide a large piece of heat shrink tubing over the
cable, and place the two small pieces of heat shrink
tubing, one over each wire, before adding crimp fit-
tings as shown in Figure 6--21.
2
1
2
1
3
4
1. Cable
2. Sensor (Typical)
3. Large Heat Shrink
Tubing (1)
4. Heat Shrink
Tubing (2)
Figure 6--21 Sensor and Cable Splice
g. Slide large heat shrink tubing over both splices and
shrink.
h. If required, slide the cap and grommet assembly onto
the replacement sensor.
i. 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.
j. Solder spliced wires with a 60% tin and 40% lead
Rosincore solder.
k. Slide heat shrink tubing over splice so that ends of
tubing cover both ends of crimp as shown in
Figure 6--21.
l. Heat tubing to shrink over splice. Make sure all seams
are sealed tightly against the wiring to prevent mois-
ture seepage.
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