3 Stage Electric Reheat – No Dead Band

iCOM Controls Training and Service Manual

of the heating proportional band. The third electric heating stage activates when the return air temperature decreases to 100% of the heating proportional band.

The temperature controller deactivates the third heating stage when the return air temperature increases to 66% of the heating proportional control band value. The second heating is deactivated when the return air temperature increases to 33% of the heating proportional control band value. The first heating stage is deactivated when the return air temperature increases to the temperature set point value or 0% of the heating proportional control band value.

3 Stage Electric Reheat – No Dead Band

Temp Set Point - (1/2 Proportional Band)

Temp Set Point: 70°F

 

 

 

 

Proportional Band: 8°F

 

Reheat 1 On

 

 

 

 

 

Reheat 3 On

Reheat 2 On

 

 

 

 

 

 

65

66

67

68

69

70

 

 

Reheat

Reheat

Reheat

 

 

2 Off

 

1 Off

 

 

3 Off

 

 

 

 

 

 

Decreasing Temperature

 

 

 

 

Note: in the above example that the control band begins at the 70°F temperature set point and has a length of 4°F, which is ½ of the programmed temperature proportional band value.

As the return air temperature decreases Reheat 1 is activated at 68.7°F or 33% of the heating control band. If the return air temperature continues to decrease Reheat 2 will activate at 67.4°F or 66% of the heating control band. If the return air temperature continues to decrease Reheat 3 will activate at 66°F or 100% of the heating control band.

When the return air temperature starts to increase, Reheat 3 is deactivated at 67.4°F or 66% of the heating control band, Reheat 2 is deactivated at 68.7°F or 33% of the heating control band and Reheat 1 is deactivated at the temperature set point of 70°F or 0% of the heating control band.

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Liebert TM-10098 service manual Stage Electric Reheat – No Dead Band, iCOM Controls Training and Service Manual