Auto-Zone Control Systems Auto-Zone CV-C Controller Installation Guide (Version 01A) - Manual (Page 26)

Section 2 Auto-Zone CV-C
2-16 Sequence of Operation
Example: Deadband = 1°F
Setpoint = 72°F
Stage #1 Activates @ 71.5°F - Deactivates @ 72.5°F
Stage #2 Activates @ 71.0°F - Deactivates @ 72.0°F
Stage #3 Activates @ 70.5°F - Deactivates @ 71.5°F
Heating can stage off if the following conditions are true.
a. The space temperature has risen enough to remove a demand for the
currently active stage. ( see previous screen for stage off levels )
b. The outside air has risen enough to disable the heating.
c. The Supply Air has risen above 150°F or 65.5°C.
d. Someone has reduced the number of heating stages to less than what are
currently active.
e. The heating stage has been on at least one minute.
The heat staging always occurs based on both temperature demand and specific intervals
based on whether the unit is staging up or down. There are four timers that need to be
satisfied:
a. Staging Delay Timer ( User Adjustable )
If a large demand exists when the heating mode is entered all available
stages would be called for. Only one stage at a time can actually be
activated. The Staging Delay period must be satisfied before each additional
stage is activated.
b. M inimum Run Timer ( Not Adjustable )
Once a stage has been activated, it must remain for at least one minute
before it is allowed to turn off again. This protects the equipment from short
cycling.
c. Minimum Off Timer ( User Adjustable )