Emerson Liebert iCOM Manual De Usuario

Standard Mode
In Standard mode, the SCR reheat operates only when the Temperature Proportional Band calls for 

heating. SCR reheat output is adjusted proportionally as the Temperature Proportional Band varies 

the requirement for heating from 0% to -100%. Compressors operate only when there is a call for 

cooling as described in 3.3.2 - Compressor Control.
Figure 44 illustrates how SCR reheat operates when SCR Control Type is set to Standard mode.

There are a variety of humidifier options depending on model unit and application requirements. In 

all humidifier applications, operation is limited to 80°F (26°C) return air temperature. If the return 

air temperature reaches 80°F (26°C) or higher during operation, the humidifier will be disabled. After 

reaching the lockout threshold, the temperature must fall to 75°F (24°C) or below 80°F (26.7°C) for 20 

minutes before the humidifier is permitted to operate.
This safety routine does not apply to externally mounted humidifiers.
Contact technical support need assistance adjusting the humidifier lockout and/or reset point or if 

there are humidification problems as a result of this routine.
The Liebert iCOM has four humidity sensor control types: Dew Point, Relative, Compensated and 

Predictive. The humidity sensor adjusts how the Temperature and Humidity Control determines the 

percent requirement for humidification/dehumidification. The humidity sensor control type 

parameter, Humidity Control Type, is in both the User and Service menus under Setpoints.
Dew Point—The actual return temperature and humidity measured by Liebert iCOM is used 

internally to determine the dew point. When dew point control is selected, the user will set the 

humidity setpoint in degrees dew point and will also adjust the proportional band in degrees dew 

point.
Relative—The actual return air humidity sensor reading is sent to the Temperature and Humidity 

Control to determine whether and how much humidification/dehumidification is required. The actual 

return air humidity reading is displayed on the Status menu. Unnecessary dehumidification can 

result when overcooling occurs during a dehumidification cycle. This is because a higher than normal 

relative humidity (RH) reading is caused by overcooling the room. This extends the dehumidification 

cycle. Later, when the dehumidification ends and the return air temperature rises to the setpoint, the 

RH reading falls. The final RH reading will then be lower than desired. If significant overcooling 

occurred, the RH could be low enough to activate the humidifier.