Honeywell EXCEL 5000 User Manual page 54

ALPHABETIC REFERENCE
74-5577–33 (US)
EN2B-0184 GE51 R0518 (Europe)
The following diagram illustrates off-time calculation for heating systems:
Cooling System Off Time Calculation
In cooling-only systems, DUC calculates off time exclusively on highest zone
temperature (X1) because cooling is only required at the high end of the
temperature range.
If temperatures are below the setpoint, the system does not operate and DUC sets
off time to the maximum (t max ).
If the maximum zone temperature is greater than the upper comfort limit, off time is
zero, that is, the system is never cycled off.
When temperature is between the setpoint and the upper comfort limit, DUC
calculates cooling off-time, t off , (YD1 or YD2 = 0) as:
DUC switches the cooling system off 10 minutes, 45 seconds before the end of the
cycle.
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EXCEL CARE CONTROL ICONS