Trane WC-IOM-7 manual Zone Temperature Sensor ZTS Test, Test Zone Temperature Thermistor ZTEMP

Troubleshooting

Zone Temperature Sensor (ZTS) Test

Note: These procedures are not for programmable or digital models and are conducted with the Zone Sensor Module electrically removed from the system.

Test 1

Zone Temperature Thermistor (ZTEMP)

This component is tested by measuring the resistance between terminals 1 and 2 on the Zone Temperature Sensor. Below are some typical indoor temperatures, and corresponding resistive values.

Table 8.

		Nominal	Nominal CSP
		ZTEMP	or HSP
Zone Temperature		Resistance	Resistance
50 F°	10.0 C°	19.9 K-Ohms	889 Ohms
55 F°	12.8 C°	17.47 K-Ohms	812 Ohms
60 F°	15.6 C°	15.3 K-Ohms	695 Ohms
65 F°	18.3 C°	13.49 K-Ohms	597 Ohms
70 F°	21.1 C°	11.9 K-Ohms	500 Ohms
75 F°	23.9 C°	10.50 K-Ohms	403 Ohms
80 F°	26.7 C°	9.3 K-Ohms	305 Ohms
85 F°	29.4 C°	8.25 K-Ohms	208 Ohms
90 F°	32.2 C°	7.3 K-Ohms	110 Ohms

Test 2

Cooling Set Point (CSP) and Heating Set Point (HSP)

The resistance of these potentiometers are measured between the following ZSM terminals. Refer to the chart above for approximate resistances at the given setpoints.

Cool SP = Terminals 2 and 3

Range = 100 to 900 Ohms approximate

Heat SP = Terminals 2 and 5

Range = 100 to 900 Ohms approximate

52 Packaged Heat Pump • WC-IOM-7