tekmar 086 Humidity & Temperature Sensor - Manual (Page 5)

© 2012 086_D - 08/12
5 of 8 A Watts Water Technologies Company
Temperature Sensor Testing Instructions
A good quality test meter capable of measuring up to 5,000 kΩ (1 kΩ = 1000Ω)
is required to measure the sensor resistance. In addition to this, the actual
temperature must be measured with either a good quality digital thermometer, or
if a thermometer is not available, a second sensor can be placed alongside the
one to be tested and the readings compared.
First measure the room temperature using the thermometer. Disconnect the Sen and
Com wires from the thermostat. Using an electrical meter, measure the resistance
of the Sen and Com wires at the thermostat location. Using the temperature versus
resistance table, estimate the temperature measured by the sensor. The sensor
measurement and thermometer readings should be close. If the test meter reads
a very high resistance, there may be a broken wire, a poor wiring connection or a
defective sensor. If the resistance is very low, the wiring may be shorted, there may
be moisture in the sensor or the sensor may be defective. To test for a defective
sensor, measure the resistance directly at the sensor location. Once the test has
been completed, reconnect the Sen and Com wires to the thermostat.
Do not apply voltage to the temperature sensor terminals at any time as damage
to the sensor may result.
The sensor has four wiring terminals that connect to a humidity sensing
thermostat.
1. Connect the Sen terminal to the thermostat temperature sensor terminal (typically
auxiliary sensor 2).
2. Connect the Com terminal to the thermostat sensor common terminal.
3. Connect the %RH terminal to the thermostat humidity sensor terminal (typically
auxiliary sensor 3).
3. Connect the +V terminal to the thermostat 0-10 Vdc terminal.
Step Five - Wiring the Sensor
+V Com %RH Sen
S3
0-1
0
Vdc
Com
S2
tekmarNet ®
Thermostat
557
Humidity &
Temperature
Sensor 086