IM 1287-6 • REBEL APPLIED ROOFTOP 78 www.DaikinApplied.com
OA Damper Start-up
1. Check whether the outdoor air is suitable for free cooling
by displaying the keypad menu Main Menu\Manual
Control\OA Damper Position=30%.
a. Verify that the OA damper position moved and the
Return air damper (if present) also moved.
b. Leave OA damper Open for next step
Return/Exhaust Fan Start-up
1. Verify all duct and unit mounted isolation dampers are
open.
2. Activate the Fan through the keypad menu Main Menu\
Manual Control\Ret/Exh Fan = On;Set Ret/Exh Fan Cmd =
40%
a. Check Fan rotation for proper rotational direction
3. Speed the fan Up through the keypad menu Main Menu\
Manual Control\Set Ret/Exh Fan Cap Cmd = 100%
a. Check the manual motor protectors or that the
circuit breakers have not tripped.
b. Check the phase monitor.
4. Verify the DHL safety, if included, is opening at a
pressure compatible with duct working pressure limits.
NOTE: Supply and return or exhaust fans should be adjusted
for proper airow during air balancing.
See “Air Balancing” on page 81
Leaving Manual Control when complete through the keypad
menu Main Menu\Manual Control\Manual Ctrl = Normal
Cooling/Heating Start up
Supply Fan Start-up
1. Verify all duct and unit mounted isolation dampers are
open.
2. Place the unit into Fan Only through the keypad menu.
Main Menu\Quick Menu\Ctrl Mode= FanOnly
a. The fan will activate.
b. Check the manual motor protectors or that the
circuit breakers have not tripped.
c. Check the phase monitor.
3. Verify the DHL safety, if included, is opening at a
pressure compatible with duct working pressure limits.
NOTE: Supply and return or exhaust fans should be adjusted
for proper airow during air balancing.
See “Air Balancing” on page 81
Economizer/OA Damper Start-up
1. Check whether the outdoor air is suitable for free
cooling by displaying the keypad menu Main Menu\
ViewStatus\Economizer\FreeClgStatus=Avai or Unavaill
verify that the enthalpy changeover control is working
properly. You may want to take temperature and humidity
measurements.
2. At the keypad, set the cooling setpoint low enough so
that the controller will call for cooling. Adjust the value
in Commission Unit\CoolingSet-Up\Occ Clg Spt below
the temperature shown as Control Temp in the same
menu. In addition, on DAC units, adjust the value in
Commission Unit\CoolingSet-Up\DAT Clg Spt below the
temperature shown in Disch Air in the same menu.
3. Place the unit into cooling mode through the keypad
menu Quick Menu\Ctrl Mode = Cool Only.
4. Observe the outdoor air dampers:
a. If the outdoor enthalpy is low, the control algorithm
should start to modulate the dampers open to
maintain the discharge air setpoint.
b. If the outdoor enthalpy is high, the dampers should
maintain their minimum position. Look at menu
ViewStatus\Economizer\Min OA Pos. Change this
entry to another value. Verify that the dampers
move to the new minimum position setpoint.
5. If the unit is equipped with comparative enthalpy
sensors, no adjustment is necessary. MicroTech
compares the energy required to cool and dehumidify the
outside air vs the return air and decides which is less.
NOTE: It may not be possible to check the economizer
operation in both low and high enthalpy states on the
same day. If this is the case, repeat this procedure on
another day when the opposite outdoor air enthalpy
conditions exist.
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