IOM-PreciseAIR
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9.
A PLC will control system capacity by cycling the compressor(s) and hot gas bypass when
the space/room air relative humidity is above setpoint plus a threshold. The Relative
Humidity demand override the Cooling demand, thus forcing the compressors to run
loaded even in situations when the temperature is satisfied. The system demand will
increase to maintain the temperature of the air leaving the coil at a setpoint which
corresponds to the wet bulb temperature of the space/room temperature and relative
humidity set points.
10.
To avoid over cooling during dehumidication, the system will re-heat the air temperature
using a duct mounted electric resistance heater.
11.
Some systems are fitted with VFD controlled blowers. In those cases, while in relative
humidity control, if the temperature leaving the coil is above setpoint even with
compressors running at 100%, the system will slow down the blowers and decrease the
airflow until temperature reaches the desired set point.
12.
Safety controls are designed into the compressor(s) and blower(s) control circuit. If any
of these safeties sense a problem the appropriate contact will open/close and shut down
the compressor. The HMI screen indicates status and alarms.
13.
If either the compressor motor or fan motor draws excessive current caused by overloads
or short circuits, the current limiting overloads will trip and isolate the faulty motor from
the 3 phase power line.
Important:
Determine cause of over current before resetting overload. To reset open
control panel with main power "OFF" and press the reset switch on the overload.
14.
Multiple alarm conditions are monitored during operation.
Содержание PreciseAIR PCA Series
Страница 15: ...IOM PreciseAIR Page 15 of 50 2 13 Main Control Panel Layout and Components Figure 4 Main Control Panel Layout...
Страница 27: ...IOM PreciseAIR Page 27 of 50 3 6 Setpoint Screens...
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Страница 49: ...IOM PreciseAIR Page 49 of 50 4 11 Maintenance Logs...
