Setting Up Alerts And Diagnostics - Honeywell Prestige 2.0 THX9421 Manual

6. Set Minimum and Maximum Delta T Limits based on
what you consider to be unacceptable performance
from the heating and cooling equipment.
NOTE: When the system operates below the
Minimum Limit or above the Maximum
Limit multiple times (Table 7), an alert is
recorded in the log. If configured to do so,
the thermostat will display an alert to the
user, along with your contact information.
7. Delta T Diagnostics is only for non-zoned forced air
systems.
8. The thermostat does not provide Heat or Cool Delta
T Diagnostics when it is set to control an Economizer
module (ISU 2220).
9. The thermostat cannot be setup for Heat Delta T
Diagnostics when the thermostat is used with an
external fossil fuel kit (ISU 2190).

Setting up Alerts and Diagnostics

1. Set up the Return and Discharge Air Sensors by
selecting the check boxes on the screen. These
sensors are used to measure Delta T.
Fig. 149.
2. Select the terminals that are wired to the Discharge
and Return Air Sensors (terminals S1, S2, S3, or S4 at
the EIM).
IMPORTANT
Be sure to select the correct terminals for the dis-
charge and return air sensors. For example, if the
return air sensor is wired to S1, select S1 (see Fig.
150) for the return air sensor.
Fig. 150.
®
THX9321 PRESTIGE 2.0 AND THX9421 PRESTIGE
3. Select the Discharge and Return Air Sensor Type
(10K).
IMPORTANT
10K sensors must be used for Delta T Diagnostics.
4. Turn on the Heat and Cool Delta T Diagnostics.
Default is On.
87
®
IAQ WITH EIM
Fig. 151.
Fig. 152.
Fig. 153.
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