Carrier 69NT20-531-300 manual Cut wires 5 cm 2 inches from shoulder of defec, 43,200 423,300

Table 6-2 Sensor Temperature/Resistance Chart				b. Cut wire(s) 5 cm (2 inches) from shoulder of defec-
	(+/--.002%)			tive sensor and discard the defective probe only.
Temperature		Resistance		c. Cut one wire of existing cable 40 mm (1-1/2 inch)
				shorter than the other wire.
_C	_F	(Ohms)
				d. Cut one replacement sensor wire (opposite color)
		AMBS,	CPDS
				back 40 mm (1-1/2 inch). (See Figure 6-19.)
		CPSS,
				e. Strip back insulation on all wiring 6.3 mm (1/4 inch).
		DTS, RTS,
		RRS, STS,		f. Slide a large piece of heat shrink tubing over the
		SRS		cable, and place the two small pieces of heat shrink
-30	-22	177,000	1,770,000	tubing, one over each wire, before adding crimp fit-
-25	-13	130,400	1,340,000	tings as shown in Figure 6-20.
					Sensor (Typical)
-20	-4	97,070	970,700
-15	5	72,900	729,000
-10	14	55,330	553,000		Heat Shrink
-5	23	43,200	423,300	Cable	Tubing (3)
0	32	32,650	326,500
5	41	25,390	253,900	Large Heat Shrink
10	50	19,900	199,000
				Tubing (1)
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 6-2.

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 reading will usually be much higher or lower than the resis- tance values given.

6.22.2 Sensor Replacement

a. Turn unit power OFF, disconnect power supply and remove sensor assembly from unit.

Figure 6-20 Typical Sensor and Cable Splice

g. 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.

h. Solder spliced wires with a 60% tin and 40% lead Rosincore solder.

i.Slide heat shrink tubing over splice so that ends of tubing cover both ends of crimp as shown in Figure 6-20.

j.Heat tubing to shrink over splice. Make sure all seams are sealed tightly against the wiring to prevent mois- ture.

k.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 resistance.

l.Position sensor in unit as shown in m.Figure 6-21 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 crimping tool. and re-check sensor resistance.

n. Reinstall sensor, refer to paragraph 6.22.3.

NOTE

The P5 Pre-Trip test must be run to inactivate probe alarms (refer to paragraph 4.7).

6-17 T-309