Data Aire dap4 touch, Инструкция по установке, эксплуатации и обслуживанию

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75 • dap4 User Manual
If Low dewpoint setpoint is set too high, the humidifier might run pass the relative humidity set-
point. When this happens, the humidifier 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 fixed 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 configuration
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 fixed 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 five (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 satisfies.
-- 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):