Liebert TM-10098 service manual Infrared Humidification – With Dead Band

iCOM Controls Training and Service Manual

Infrared Humidification – With Dead Band

Humidity Set Point - (1/2 Dead Band + 1/2 Proportional Band)
				Humid Set Point: 50%
				Proportional Band: 8%
Humidification On				Dead Band: 2%
45	46	47	48	49	50
					DB
	Humidification Off
			Increasing Temperature

Note: in the above example that the control band begins at the 50% humidity set point and has a length of 5%, which is ½ of the programmed dead band value plus ½ of the programmed humidity proportional band value.

As the return air humidity decreases the infrared humidifier is activated at 45%RH or ½ of the dead band value plus 100% of the humidification control band. When the return air humidity starts to increase, the infrared humidifier is deactivated at 47%RH or ½ of the dead band value plus 50% of the humidification control band.

Autoflush Control for Infrared Large (IFL) or Small (IFS) Pans

The Autoflush Water-Level Control software program is an integral part of the infrared humidifier system. The program automatically controls a water makeup valve to maintain the proper water level in the humidifier pan during operation. When a call for humidification exists, the program performs a series of checks.

The first check to see how long the infrared humidifier has been off. If the off time is equal to or greater than the programmed value (factory default is 15 hours), it is assumed that the pan is dry and a program called pre-fill is initiated to add water to the pan. During the pre-fill operation the infrared lamps are inactive. The pre-fill time is programmable with an adjustable range of 1 to 120 seconds for either pan size. The factory default for a large (IFL) pan is 60 seconds and for a small (IFS) pan is 30 seconds.

28