Daikin MICROTECH 4 Operation Manual page 56

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Sensible DX Bypass Applications
A Sensible DX Bypass Application occurs only in dry climates
when the design SHR is greater than 0.8. In this scenario, no
additional dehumidification devices are required. Blenders can be
useful for applications where the OA is >30% of the SA CFM .
Latent DX Bypass Applications
A Latent DX BP Application can occur in any climate zone
where the design SHR is between 0.7 and 0.8. If the unit
is a mixed air unit, it is recommended the unit use hot gas
reheat (HGRH) for supplemental dehumidification control.
HGRH dehumidification should be configured to trigger
based on OADewpoint and the space set point . Review
the Dehumidification Set-up menu on how to configure
Dehumidification to use two setpoints. The OA Dew point should
be set to 60F or lower . Blenders are highly recommended if
the OA is >20% of SA CFM in latent applications . This will help
ensure you are mixing properly before the DX Coil and Bypass
Damper control .
DAIKIN APPLIED
DX Coil Bypass Damper LCT Reset
The DX Bypass LCT Set point may be reset for units with
DX Bypass Dampers . The reset type may be set to one of the
following:
• None: DXBP LCTSpt is user adjustable
• Network: DXBP LCTSpt is equal to the Network DAT Clg
Set point when it is valid
• Space: DXBP LCTSpt is based on the Space Sensor
• Return: DXBP LCTSpt is based on the Return Air Sensor
• OAT: DXBP LCTSpt is based on the Outdoor Air
Temperature
• Ext mA: DXBP LCTSpt Spt is determined by a 0-20 mA
signal
• Ext V: DXBP LCTSpt is determined by a 0-10 VDC signal
• Airflow: DXBP LCTSpt is based on the airflow as indicated
by the variable frequency drive speed
• SpaceH1: DXBP LCTSpt is based on the humidity based
on humidity sensor 1 .
• SpaceH2: DXBP LCTSpt is based on the humidity based
on humidity sensor 2 .
• SpcDwpt1: DXBP LCTSpt is based on the calculated dew
point based on dew point sensor 1
• SpcDwpt2: DXBP LCTSpt is based on the calculated dew
point based on dew point sensor 2
• OADwpt: DXBP LCTSpt is based on the calculated
Outdoor Air Dew point
• RADwpt: DXBP LCTSpt is based on the calculated Return
Air Dew point
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 .
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MICROTECH UNIT CONTROLLER