Data Aire dap 4 - Page 76

76•dap4UserManual
-- When return air temperature = Temperature setpoint + temperature deadband
  variablespeedcompressorstartsandrampuptomaximumspeed.Forinstance:
SP = 72, DB = 2. Compressor will be on at 74°.
-- Variable speed compressor will then use PI (Proportional and Intergral) control
algorithm to main the setpoint. Proportional band is the same as deadband. The
Intergral band is programmed in Factory settings menu. In most cases there is no
  needtochangethePandIvalueastheresultoftemperaturecontroluctuation.
Return air temperature is dropping (Off cycle):
-- As the return air temperature reaches setpoint, the compressor will ramp down
to its minimum speed. (Note: If variable speed compressor runs at the minimum
  speedforalongperiodoftime,itwillautomaticallyrampuptothemaximumspeed
for one minute to maintain the minimum compressor oil level. The temperature may
drop slightly during this override period).
-- Compressor continues to run at minimum speed then turns off when return air
temperature drops to temperature setpoint – C1 offset. C1 offset is programmed
in Compressor/Factory settings menu, default value is 2°F. For instance: SP= 72,
C1 offset = 2, compressor goes off at 70°.
b) DualDXcircuit:Combinationofavariablespeedcompressor(C1)andaxedspeed
compressor (C2)
-- Compressor settings type in dap4 Factory Settings menu is programmed to
  “Variable+xed”andControlmodeissetto“ReturnTemp”.
 -- Thereisave(5)minutedelaybetweenstart-to-startofthesameprimarystage.
  Thedelaywillbeincreasedtosix(6)minutesforone(1)hourfollowingthedetection
of a short-cycle condition even if the short cycle alarm is disabled using a short cycle
alarm menu.
-- There is a two (2) minute delay between stop-to-start of the same compressor.
-- There is minimum two (2) minutes delay between the start of variable speed
  compressorandstartofxedspeedcompressor.
-- Once variable speed compressor C1 comes on, it must remain on for a minimum
  runtimeevensetpointsatises.
-- Compressor cycles on and modulate as follows:
Return air temperature is rising (On cycle):
-- When return air temperature rises to temperature setpoint + temperature deadband,
  VariablespeedcompressorC1willstartandrampuptoitsmaximumspeed.
For instance: SP = 72, DB = 2. Compressor will be on at 74°.
-- Variable speed compressor will then use PI (Proportional and Integral) control
algorithm to main the setpoint. Proportional band is the same as deadband.
The Integral band is programmed in Factory settings menu. In most cases there is
no need to change these P and I settings.
 -- FixedspeedcompressorC2cyclesonwhenreturnairtemperaturerisesto
temperature setpoint + temperature DB + stage-to-stage Band and compressor C1
  hasoperatedatabove95%ofitsmaximumspeedforthe“C2ondelay”period.C2
on period is programmed in Compressor/Factory settings menu (default=60s).