Daikin EWWQ-AJYNN Service Manual page 79

ESIE07-05
Graph 2 The derivative part of the logic controls how the temperature reaches the setpoint. If it is getting closer
– increases the time between intervals, or if it is far from the setpoint – decreases the time between
intervals. The result is having the controller act differently whenever the water temperature changes.
If the derivative time is increased, the control will be more sensitive to temperature changes. For
example: the derivative time can be increased when a chiller is working with a very variable load. The
integral time stores the memory on how the P+1 controls the temperature.
Part 2 – Functional Description
Pulse time
Minimum loading pulse
time
Max loading pulse
time
Pulse
stand-by
If temperature is
far from set-point
Functional Control
If temperature is
close to set-point
Evap water leaving
2–73
1
2
3
4
5