Daikin MicroTech III User Manual

Discharge Air Temperature Setpoint Reset - Cooling
The Cooling DAT Setpoint may be reset for units with DAT
Cooling Control. The reset type may be set to one of the
following:
• None: Discharge Cooling Spt is user adjustable
• Network: Discharge Cooling Spt is equal to the Network
DAT Clg Setpoint when it is valid
• Space: Discharge Cooling Spt is based on the Space
Sensor
• Return: Discharge Cooling Spt is based on the Return Air
Sensor
• OAT: Discharge Cooling Spt is based on the Outdoor Air
Temperature
• Ext mA: Discharge Cooling Spt is determined by a 0-20
mA signal
• Ext V: Discharge Cooling Spt is determined by a 0-10
VDC signal
• Airow: Discharge Cooling Spt is based on the airow as
indicated by the variable frequency drive speed
Reset reverts from Return to None when a Return Air Sensor
opens or shorts. Reset reverts from Space to None when a
Space Sensor opens or shorts. Reset reverts from OAT to
None when an Outdoor Air Sensor opens or shorts.
When Space, Return, OAT, Airow, Ext mA, or Ext V is
selected, the Discharge Cooling Spt equals the Max Clg Spt
when the selected value equals the Max Clg Spt @ value.
Similarly, the Discharge Cooling Spt equals the Min Clg Spt
when the selected value equals the Min Clg Spt @ value.
When Space, Return, OAT, or Airow is selected, the reset
schedule should be set so that the DAT Cooling setpoint
decreases as the selected temperature increases as shown in
the graph.
Figure 17: Cooling Setpoint
When Airow is selected, the values “Min Clg Spt @” and
“Max Clg Spt @” are entered as percentage values. When
Ext mA is selected, the values “Min Clg Spt @” and “Max Clg
Spt @” are entered as mA values. When Ext VDC is selected,
the values “Min Clg Spt @” and “Max Clg Spt @” are entered
as VDC values.
If Ext mA or Ext V is selected as the type of reset, the Min Clg
Spt @ value may be set above the Max Clg Spt @ value to
cause a decrease in the DAT setpoint as the external signal or
the Min Clg Spt @ value may be set below the Max Clg Spt @
value to cause an increase in the DAT setpoint as the external
signal increase.
The Min Clg Spt @ value can be set below the Max Clg Spt
@ value for all types of reset, but it only makes sense for
external reset.
When ever the Clg Reset Type or Engineering Units is
changed, the Min Clg Spt @ and Max Clg Spt @ values revert
to default values as follows:
• None: Min Clg Spt @=0NA, Max Clg Spt @=100NA
• Network: Min Clg Spt @=0NA, Max Clg Spt @=100NA
• Space, Return: Min Clg Spt @=73.0F, Max Clg Spt
@=71.0F
• OAT: Min Clg Spt @=90.0F, Max Clg Spt @=70.0F
• ExtmA: Min Clg Spt @=4.0mA, Max Clg Spt @=20.0mA
• ExtVDC: Min Clg Spt @=0.0V, Max Clg Spt @=10.0V
• Airow: Min Clg Spt @=33%, Max Clg Spt @=100%
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Daikin MicroTech III Specifications

General

Brand	Daikin
Model	MicroTech III
Category	Controller
Language	English