tekmar 070 Outdoor Sensor - Manual (Page 2)

© 2012 070_D - 12/12
2 of 4 A Watts Water Technologies Company
STEP TWO
WIRING AND TESTING THE SENSOR
• Connect 18 AWG or similar wire to the two terminals provided in the enclosure and
run the wires from the 070 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 instruction in this brochure and connect the wires to the
control.
• Replace the front cover of the sensor enclosure.
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.
Wires from outdoor
sensor to control’s
outdoor sensor and
sensor common
terminals
Sensor is built into
the enclosure
Sensor Testing Instructions