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80•dap4UserManual

-- If variable speed compressor C1 runs at the minimum speed for a 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 cycles on and modulate as follows:

Discharge air temperature is rising (On cycle):

-- When discharge air temperature rises to temperature setpoint + temperature DB

(deadband), variable speed compressor C1 will start and operate at its minimum

speed.

-- Dap4 will then use PID (proportional-Integral- derivative) control logic to modulate

the variable speed compressor C1 to maintain temperature setpoint. PID values are

programmed in Factory settings menu.

Discharge air temperature is dropping (Off cycle):

-- Compressor C1 turns off when discharge air temperature drops to temperature

setpoint – C1 offset. C1 offset is programmed in Compressor /Factory settings

menu.

 -- CompressorC1canonlyturnoffifminimumruntimehasexpired.

b) DualDXcircuit:Combinationofavariablespeedcompressor(C1)andaxedspeed

compressor (C2) system

-- Compressor settings type in dap4 Factory Settings menu is programmed to

  “Vari+Fixed”andControlmodeissetto“Supply”.

 -- 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:

Discharge air temperature is rising (On cycle):

-- When discharge air temperature rises to temperature setpoint + 0.5 temperature

deadband (SP+1/2 DB), variable speed compressor C1will start.

-- Dap4 will then use PID (proportional- Integral- derivative) logic to control the

compressor C1 speed to maintain temperature setpoint.

 -- FixedspeedcompressorC2willcomeonwhendischargeairtemperaturerises 

to temperature setpoint + temperature deadband (SP+DB) and compressor C1 has

  operatedatabove95%ofitsmaximumspeedforatleastC2ondelay.C2ondelay

is programmed in Compressor/Factory settings menu.

Data Aire dap 4 User Manual

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