Data Aire dap 4 User Manual

75•dap4UserManual
IfLowdewpointsetpointissettoohigh,thehumidiermightrunpasstherelativehumidityset-
point.Whenthishappens,thehumidierwillbeinhibitedandawarningwilldisplayondap4LCD
screen.
Variable Speed Compressor Control Logic and EEV Safeties
and Alarms
System with Variable Speed Compressor
Data Aire gForce Ultra DX series unit can be equipped with a variable speed compressor or a
combinationofavariablespeedcompressorandaxedspeedscrollcompressor.Inthesetypes
of unit, Dap4 controller will modulate the VFD of the variable speed compressor using a 0-10VDC
signal to maintain either return air temperature setpoint or supply (discharge) air temperature set-
point.
 Dap4Softwareconguration
i) There will be two additional compressor type selections added to compressor type:
  Var.Sp(singlevariablespeedcompressor)andVar.Sp+FixedSp(avariable 
  speedplusaxedspeedcompressor)
ii) Control mode: Return /Supply. Return is default setting. When control mode is set to
Return, compressors will be controlled by the return air temperature sensor. When
Supply is selected, compressor will be controlled by the discharge air temperature
sensor.
iii) An adjustable Minimum runtime for variable speed compressor with a range of 2- 10
minutes is added the Factory Setting menu, default value is 2 minutes.
iv) There will be no compressors rotation when unit has a variable speed
compressor. Variable speed compressor is always the lead compressor.
1. Return Air Temperature Control Mode
a) Single DX circuit- one variable speed compressor system
-- Compressor settings type in dap4 Factory Settings menu is programmed to “Single
Variable” and Control mode is set to “Return Temp”.
 -- Thereisave(5)minutedelaybetweenstart-to-startofthecompressor.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.
-- Once variable speed compressor C1 comes on, it must remain on for a
  minimumruntimeevensetpointsatises.
-- 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 C1 cycles on and modulate as follows to maintain setpoint:
Return air temperature is rising (On cycle):

Data Aire dap 4 Specifications

General

Brand	Data Aire
Model	dap 4
Category	Control Unit
Language	English