Munters HCUw, Эксплуатация и техническое обслуживание

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6
4 OPERATING INSTRUCTIONS
4.1 CONTROLS
The unit is controlled and monitored by a Novar IOM or Danfoss
controller
. The HCU has a
microprocessor
to supervise and control all internal functions. The IOM provides eight dry contact
closures to control the supply fan and stages of: cooling, dehumidification, and heating as shown on the
wiring diagram. The controller also monitors inputs as shown on the wiring diagram.
4.2 STARTING THE UNIT
Turn the disconnect switch for the HCU on.
The unit will start when the external FAN contacts close on the IOM. The unit will also start when either
the COOL, DH, or HEAT contacts close.
4.3 UNIT OPERATION
The controller will sense space conditions and call for two stages of cooling, DH, or stages of heating as
required to maintain space conditions. Digital inputs 4 and 7 must be connected with a jumper wire
(terminals 37 and 40). A call for dehumidification will energize compressor A. After a settable delay period
called “Comp B On” under User Settings: DEHUM OVERRIDES (default 30 minutes), compressor B will
start if the call for DH is still present. When the call for dehumidification is dropped, compressor B will de-
energize and compressor A will continue to run for a period of time called “Comp A Off” under User
Settings: DEHUM OVERRIDES (default 15 minutes). Stage 2 DH will not energize if:
1. Outside air temperature is below set point: OUTSIDE AIR TEMPERATURE Comp B Set: (default)
65°F.
2. Outside air damper DI8 is not energized.
3. Suction pressure is below set point: COMP B – CYCLE ON MIN SUCTION PRESSURE Set
point: (default) 128 psig (R410a).
NOTE:
The night setback digital input (DI8 Outside Air Damper) must be jumpered to terminal 20. When
DI8 is not energized, compressor B will not operate.
The HCU microprocessor can be set for temperature priority or humidity priority mode of operation. In
Humidity priority (default position), the desiccant wheel will operate along with the compressor anytime
DH is called for by the external controller. In Temperature priority mode, the desiccant wheel will shut off if
the external controller calls for cooling while calling for DH. This mode of operation defaults as Humidity
priority. The mode can be changed in the CONTROL SETUP screen under USER SETTINGS on the
microprocessor.
The external controller may be overridden if the outside conditions are above user adjustable set points.
There are adjustable compensations for high outdoor ambient temperature and humidity conditions to
prevent swings in indoor conditions.
This is accomplished by setting desired “overrides” for differences between outdoor and desired indoor
temperature and grain levels. If the difference exceeds these adjustable overrides, the appropriate stages
of cooling or DH will remain on even though indoor conditions are met. See 4.6 USER SETTINGS.
4.4 USING THE CAREL MICROPROCESSOR
The Carel pCO2 microprocessor has a keypad and display to allow the operator to view the status of
various functions, set parameters with authorization to up to three levels of security, and to troubleshoot
problems that may occur.
The keypad and display are located on the microprocessor inside the control panel.
CAUTION!
There is
high voltage inside the control panel. Do not touch anything other than the keypad on the display.