Munters HCUw, Operating & Maintenance

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LEVEL 03: 0003 Password (number)
for factory access
FACTORY SETTINGS
Model Num: HCUb410 Set to HCU model
Control Method: STD STD for I/O control
BMS for
communicating
control
4.5 SHUT DOWN
De-energizing output 1 on the CONTROLLER will shut the unit down.
4.6 ADJUSTING SUPPLY AIRFLOW
The supply airflow is adjusted by moving the direct drive supply fan closer to or farther away from the inlet
cone. Maximum airflow is attained when the inlet cone is just inside the blower wheel inlet. Moving the
motor/blower wheel away from the inlet cone reduces the airflow.
4.7 CONDENSER AND REACTIVATION FAN CONTROL
The reactivation fan is controlled by 2 VFD (variable frequency drive) and the condenser fans are
controlled in tandem by 3 VFD. Each VFD receives a 0 – 10 volt DC analog signal from the
microprocessor to control the speed of the fan to maintain a constant discharge pressure of 444 psig
during dehumidification mode and 340 psig during cooling-only mode. 2 VFD (reactivation fan) will
modulate from 50% minimum to 100%. 3 VFD (condenser fans) will energize and modulate from 20% up
to 100% as required. The purpose of the 444 psig discharge pressure during dehumidification mode is to
maintain sufficient condenser coil leaving air temperature for reactivation. At higher ambient
temperatures, it is normal for the discharge pressure to increase above these set points. See Appendix C
for VFD settings.