Operation Of Reheat - Data Aire dap4 User Manual

Operation of Reheat

The dap4 can be configured to use the following reheat modes:
None - No reheat installed. DX dehumidification cannot operate.
One - A single stage of reheat.
1-Elect - A single stage of reheat but runs only in dehumidification mode.
HW Valve - (Not on IRDX Model). A discharge air temperature sensor must
be installed to select this mode. An On/Off Hot Water valve connects to heat
stage 1 output and if modulated type, uses the SCR output (Y4). (dehum
fan speed is not affected by using HW valve).
Two - (Not on IRDX Model or MiniDAP). Two stages of reheat.
Three - (Not on IRDX Model or MiniDAP). Three stages of reheat.
3-Elect - (Not on IRDX Model or MiniDAP). Three stages of reheat but runs
only in dehumidification mode.
HGRH – A modulated Hot Gas valve connects to output (Y4). It is
modulated to maintain return/discharge air temperature only while
compressor is running in the dehum mode.
HGRH+1 – Operates the same as the HGRH mode but will have a second
reheat stage.
HGRH+SCR Operates the same as the HGRH mode but will also use SCR
modulated reheat that can operate without dehum mode.
Safeties: The heaters will be shut down under the following conditions: Air Flow
Alarm, Condensation Alarm, Fan Overload Alarm, or a Reheat Inhibit command
(from BMS, Zone Master, or custom alarm input).
Note: Heating will be interrupted if humidification is running when the humidifier is
set to a "Computer" mode).
Timed Safeties: There is a 60 second delay between heating stages.
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