Setting First And Second Stage Differentials - AMX ENV-VST-C Instruction Manual

The following table lists the options on the Thermostat Setup screen:
Thermostat Setup Screen Options
First Stage Diff
Second Stage Diff
Deadband
Temperature Offset
Balance Point
Exit

Setting First and Second Stage Differentials

Differentials set the tightness of the temperature control to eliminate large temperature swings and prevent the HVAC system from
operating too often. Normally the second stage of heat is for auxiliary or emergency heat.
Perform these steps to set the first and second stage differentials:
1. From the Main screen, press Mode/Select to access the Thermostat Mode screen.
2. Use the navigation buttons to select Settings, and press Mode/Select. The Settings screen appears.
3. Use the navigation buttons to select Advanced Settings. Press Mode/Select to access the Security Code screen.
4. Enter the security code, and select Enter to access the User Preferences screen. See the Entering the Security Code on
page 30 for more information.
5. Use the navigation buttons to highlight More, and press Mode/Select to access the second User Preferences screen.
6. On the second User Preferences screen, use the navigation buttons to highlight More, and press Mode/Select to access the
third User Preferences screen.
7. Use the navigation buttons to highlight Advanced Setup, and press Mode/Select to access the Advanced Setup screen.
8. Use the navigation buttons to highlight More, and press Mode/Select to access the second Advanced Setup screen.
9. Use the navigation buttons to highlight Thermostat Setup, and press Mode/Select to access the Thermostat Setup screen
(FIG. 48).
Thermostat Setup screen (1 of 2)
FIG. 48
10. With First Stage Diff highlighted, press Mode/Select to activate it.
11. Press Mode/Select to indicate the first stage differential.
ENV-VST-C - Instruction Manual
Enables you to set the 1st stage temperature differential. Differentials set the tightness of the temperature control
to eliminate large temperature swings and prevent the HVAC system from operating too often. Normally the
second stage of heat is for auxiliary or emergency heat.
• You can choose from 0.5°F, 1.0°F, and 2.0°F (or 0.25°C, 0.5°C, 1.0°C).
• The default value is 0.5°F (0.25°C).
Enables you to set the 2nd stage temperature differential.
• You can choose from 1.0°F, 2.0°F, 3.0°F, 4.0°F, 5.0°F, and 6.0°F (or 0.5°C, 1.0°C, 1.5°C, 2.0°C, 2.5°C, 3.0°C).
• The default value is 2.0°F (1.0°C).
The Deadband is the temperature difference between the heating and cooling setpoints. The Deadband
configuration enforces a minimum separation between the two setpoints which determine when auto changeover
between HVAC heating and cooling mode will occur.
• You can choose from 2.0°F, 3.0°F, 4.0°F, and 5.0°F.
• The default Deadband is 4.0°F.
The temperature offset enables you to customize the temperature shown on the display. You can set the
temperature offset between 10 and -10 in 1° increments. Selecting a positive increment decreases the displayed
value, while selecting a negative increment increases it.
The default temperature offset is 0.
Balance Point configuration enables you to adjust a low or high balance point to limit auxiliary heat pump
operation according to the current outdoor temperature.
• The compressor terminals will not be energized when the outdoor temperature is below the balance point.
• This does not affect Emergency Heat operation.
• This option is only valid if the thermostat has been configured to operate as a heat pump.
• The default Balance Point is 30°F.
Returns you to the Advanced Setup screen.
Advanced Thermostat Operations
44