Com (–) terminal on the control and not to earth
ground.
•
Run wires from the 24-30 V (ac) power source or
heat demand to the electrical box for the wiring.
Use a clean power source to ensure proper
operation.
Wiring and Testing the Outdoor Air Temperature
Sensor 070
CAUTION: No wires should be connected to the
control during testing.
CAUTION: Do not apply voltage to the 070 at any time
as damage to the 070 may result.
A good quality test meter capable of measuring up to
5,000 kW (1kW = 1000 W) 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 070 sensor can be placed
alongside the one to be tested and the readings
compared.
Connect the wire to the two terminals provided in the
PVC enclosure (Fig. 7A).
First measure the temperature using the thermometer
and then measure the resistance of the 070 sensor at
the control. The wires from the 070 sensor must not be
connected to the control while the test is performed.
Using the Resistance/Temperature Chart (page 12),
estimate the temperature measured by the 070 sensor.
The 070 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
Figure 7A - Sensor Wire Connection
Page 11
