tekmar 081 Three Outdoor Sensor Module - Manual (Page 2)

© 2013 081_D - 01/13
2 of 4 A Watts Water Technologies Company
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 temperature using the thermometer and then measure the resistance of
the sensor at the control. The wires from the sensor must not be connected to the control
while the test is performed. Using the chart on the following page, estimate the temperature
measured by the sensor. The sensor 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.
Do not apply voltage to a sensor at any time as damage to the sensor may result.
STEP TWO WIRING AND TESTING THE SENSOR
• Connect 18 AWG or similar wire to the two terminals (S1 and S1) provided on the
module and run the wires from the module to the control. Do not run the wires parallel
to telephone or power cables. If the sensor wires are located in an area with strong
sources of electromagnetic interference (EMI), shielded cable or twisted pair should be
used or the wires can be run in a grounded metal conduit. If using shielded cable, the
shield wire should be connected to the Com terminal on the control and not to earth
ground.
• Follow the sensor testing instructions on the bottom of this brochure and connect the
wires to the control.
• Repeat the above steps for the second (S2 and S2) and third (S3 and S3) sensors.
• Replace the front cover of the Outdoor Sensor 070 enclosure.
Sensor Testing Instructions