Determining Heat Status - McQuay MicroTech III RAH Operation And Maintenance Manual

Operator's Guide
68

Determining Heat Status

Htg Status is a status item which indicates whether or not heating is currently allowed. If
heating is disabled, the reason is indicated. The current Heat Status can be viewed via the
following path: Standard Menu/System/Htg Status.
The following are descriptions of heating status states:
Enabled
Heating is enabled if all the following are true:
• Heating capability is provided
• Control mode is not set via the System Menu to fan only or cool only
• Control mode is set via the System Menu to auto and not disabled via a network command
• The outdoor air temperature (OAT) is low enough for operation
None
Heating capability is not provided.
Off Ambient
The OAT is too high for operation. The OAT becomes too high for operation when the OAT
rises above the OAT heating lockout set point. OAT becomes low enough for operation when
the OAT drops below the OAT heating lockout set point by more than the Heating Lockout
Differential.
Off Network
Control Mode is set via the System Menu to auto and the unit is disabled via a network
command.
Off Manual
Control mode is set to Fan Only or Cool Only via the System menu.
Determining Economizer Status
Econo Status is a status item which indicates whether or not economizer operation is currently
allowed. If economizer operation is disabled, the reason is indicated. The current Economizer
Status can be viewed via the following path: Standard Menu/System/Econo Status.
The following are descriptions of economizer status states.
Economizer is enabled if all the following are true:
• Economizer capability is provided
• Control mode is set via the System menu to auto and not disabled via a network command
• Dehumidification operation is not enabled
• The unit is configured for waterside economizer and the EWT is below the mixed air
temperature minus the EWT differential or the unit is configured for airside economizer, the
enthalpy switch input indicates low enthalpy, and the outdoor air temperature (OAT) is low
enough for operation
None
Economizer capability is not provided.
McQuay OM 920-1