Pressure Condensation Control - Daikin MICROTECH III Operating Manual

Capacity Overrides – Limits of Operation
The following conditions override automatic capacity control when the chiller is in COOL mode. These overrides keep the
circuit from entering a condition in which it is not designed to run.
Low Evaporator Pressure
If the Low Evaporator Pressure Hold event is triggered, the compressor will not be allowed to increase in capacity.
If the Low Evaporator Pressure Unload event is triggered, the compressor will begin reducing capacity.
The compressor will not be allowed to increase in capacity until the Low Evaporator Pressure Hold event has cleared.
See the Circuit Events section for details on triggering, reset, and unloading action.
High Condenser Pressure
If the High Condenser Pressure Hold event is triggered, the compressor will not be allowed to increase capacity.
If the High Condenser Pressure Unload event is triggered, the compressor will begin reducing capacity.
The compressor will not be allowed to increase in capacity until the High Condenser Pressure Hold event has cleared.
See the Circuit Events section for details on triggering, reset, and unloading action.
8.5

Pressure condensation control

If the Condensation Control Value Set Point is set to Press option, then Fan steps #1..4 control is enabled for each enabled
circuit.
According to Fan steps set point and differential default values listed in the Circuit Set Points table, the following graph
summarizes the activation and deactivation conditions for fan steps.
Fan Steps
The Fan step# (# = 1..4) control states are:
•
Off
•
On
The Fan step # control state is Off when any of the following are true:
•
Unit state is Off.
•
Fan step# state is Off and the Saturated Condenser Temperature corresponding to the current Condenser
Pressure is lower than Fan step # Set point.
•
Fan step # state is On the Saturated Condenser Temperature corresponding to the current Condenser Pressure
is lower than Fan step# Set point – Fan step# Diff.
The Tower # control state is On when all of the following are true:
•
The unit state is auto
•
The Saturated Condenser Temperature corresponding to the current Condenser Pressure is equal or higher
than Fan step# Set point
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Output
Fan Step
Fan Step
#3
Fan Step
#2
Fan Step
#1
Operation Manual
#4
T° Cond
(In/Out)
D–EOMWC00A07-16_02EN