Data Aire dap 4 - Page 98

98•dap4UserManual
Water valve action menu (Wtr Vlv Action) can be chosen for reverse acting valves. With this op-
 tionturnedon,thefanwilloperateatminimumairowwhenthevalveisfullyopenandatmaxi-
 mumairowwhenthevalveisfullyclosed.
8. Fan speed controlled by Return air temperature setpoint (Mod to R. Air)
1. There is RA Temp fan setpoint and RA Temp fan Deadband in the setpoint group. These
setpoint only display whenever the Fans speed by RA Temp mode is selected in the CW fan
mode section in Factory Setting group
 ThelogicforfanspeedusesthemaximumandminimumfanspeedsfromModulateMaxand
Modulate Min speed menus. As the return temperature rises, the fan would start at the mini-
 mumandincreaseby10%*(maximumfanspeed-minimumfanspeed)forevery0.1°Fabove
RA Temp setpoint + RA Temp deadband. Fan speed reduces to minimum speed when RA
temperature is at setpoint.
9. Mod to Rack.
See RackSense 32 User’s Manual for details.
FAN SPEED CONTROL FOR DIRECT EXPANSION (DX) UNITS
Six(6)fanspeedcontrolmodescanbeselectedforDXunits.Thecontrolmodesareaccessible
through Menu J – Factory Settings. Either of the following may be chosen:
1. Speed Constant (Const. Speed)
2. Speed Controlled by BMS (BMS Speed)
3. Static Pressure Constant (Air Pressure)
4. AirowConstant(Const.ow)
5. AirowControlledbyBMS(BMSFlow)
6. Mod to Rack
1. Speed Constant (Const. Speed) - Default
In Speed Constant mode, the dap4 will start and operate the fan at the constant speed set in
DX SPEED. The constant speed is controlled by outputting a constant voltage to the fan speed
controller.
2. Speed Controlled by BMS (BMS Speed)
In Speed Controlled by BMS mode, the dap4 will start and operate the fan at the constant
speed set in DX Speed menu until it receives a new valid fan speed (30% - 100%) from a BMS.
The constant speed is controlled by out putting a constant voltage to the fan speed controller.
 ThefanspeedwillautomaticallyincreasetothemaximumfanspeedsetinMODULATEMAX
 menuwhenreheatorhumidicationisrequired.ThefanspeedwillreverttotheBMScon- 
 trolledfanspeedsettingwhentheunitstopscallingforreheatorhumidication.
WARNING: IF CUSTOMER DECIDES TO USE THIS FAN SPEED CONTROL MODE (FAN
SPEED CONTROLLED BY BMS), DATA AIRE WILL NOT BE RESPONSIBLE FOR ANY
EFFECTS, MALFUNCTIONS OR SPACE CONTROL CONDITIONS CAUSED BY THIS
SELECTION.