WattMaster Auto-Zone Plus, Design, Installation And Operation

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Auto-Zone Plus Section 4
Start-Up and Troubleshooting 4-29
2.2.7 Analog Input Connector
This connector provides the termination point for all of the temperature sensors and the
auxiliary contact closure inputs.
All of the temperature sensor inputs (SAT, RAT, OAT) are designed to accept a standard
10K Type III thermistor temperature sensor. The sensors can be checked by
disconnecting the wires at the terminal block and comparing the resistance against the
chart at the end of this section. The sensors may also be checked by measuring the
voltage (DC Volts) at the terminal block and comparing the measured value to the chart.
The negative meter lead should be on the GND terminal.
Tip
Any inputs that m5.1 VDC are OPEN, and any inputs which have less
than +0.1 VDC are SHORTED. Look for wiring errors if this is a temperature
input.
The wiring consists of the following six inputs:
SAT - Supply Air Temperature
This input accepts a two wire 10K Type III thermistor temperature sensor. The
sensor measures 10,000 Ohms @ 77
°
F. The resistance drops as the temperature
increases. The sensor is connected between this terminal and the GND terminal.
RAT - Return Air Temperature (Same as SAT)
OAT - Outside Air Temperature (Same as SAT)
AUX1 - Economizer Disable
This input allows the Economizer to be disabled when it is SHORTED to the
GND terminal. This input is typically connected to an enthalpy sensor to disable
economizer operation during high humidity periods.
AUX2 - Filter Alarm
This input allows connection of a Dirty Filter switch, an alarm condition is
created at the System Manager when it is SHORTED to the GND terminal. This
input is typically connected to a normally open switch contact.
AUX3 - Forced Occupied Mode
This input allows another system to force the Zone Manager into the Occupied
mode of operation when it is SHORTED to the GND terminal. This input is also
useful as a test when checking the system during unoccupied periods. This input
is typically connected to a normally open switch contact.
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