Honeywell EXCEL 5000 User Manual page 187

EXCEL CARE CONTROL ICONS ALPHABETIC REFERENCE
In other words, early switch-on time equals room temperature minus room
temperature setpoint multiplied by the high-speed cooling factor. The high-speed
cooling factor indicates how many minutes the system requires to compensate for a
deviation of 1 K. It must be entered in Parameter P8, but EOV can independently
correct it. See Adaptation of Factors in this section.
Optimized Shutdown in the Cooling Mode
If the Time Program contains a switch point that shuts the system off while the
system is in cooling operation (XD5=0), EOV optimizes this switch point, that is,
EOV shuts down the system before reaching the switch point so that energy is
saved. EOV calculates shutdown advance time (T VKA ) the same way as EOH,
using a linear characteristic curve.
EOV shuts down the system with the maximum time advance if OAT is equal to the
room temperature setpoint and room temperature. In this case, EOV guarantees
that the room temperature setpoint is closely followed until the switch point is
reached in spite of early shutdown as the heat losses from the building are zero
because of OAT.
EOV shuts down the system without advance when the actual OAT is greater than
or equal to the maximum OAT (Parameter P9). Between these limits, EOV
calculates advance time (T VKA ) as follows:
Where t corr = (X2 - X3) * P10
In other words, the correction factor equals setpoint minus room temperature
multiplied by the optimum stop factor.
The correction factor changes the slope of the previously defined characteristic
curve as a function of the control difference:
If room temperature equals room temperature setpoint, the characteristic curve
remains unchanged.
If room temperature is less than room temperature setpoint, the characteristic curve
is steeper and the system is shut down earlier.
If room temperature is greater than room temperature setpoint, the characteristic
curve is less steep and the system is shut down later.
189 74-5577–33 (US)
EN2B-0184 GE51 R0518 (Europe)