Carrier RTU OPEN 11-808-427-01 - Manual (Page 59)

RTU Open 53
High Space Relative Humidity - The RTU Open generates this alarm when the space humidity exceeds the
Alarm Configuration > High Space Humidity Alarm Limit setpoint for 10 minutes. This alarm is inhibited until
the RTU runs for 15 minutes to allow for system stabilization after startup.
Low Space Relative Humidity
- The RTU Open generates this alarm when the space humidity falls below the
Alarm Configuration > Low Space Humidity Alarm Limit setpoint for 5 minutes. This alarm is inhibited until
the RTU runs for 5 minutes to allow for system stabilization after startup.
High CO2
- The RTU Open generates this alarm when the space CO2 level exceeds the Alarm Configuration >
Occupied High CO2 Alarm Limit setpoint for 1-minute. This alarm will be inhibited until the RTU has been
running for 2-minutes to allow for system stabilization after startup.
Supply Fan Runtime
- The RTU Open generates a this alarm when the accumulated runtime exceeds the Unit
Configuration > Supply Fan Service Alarm Timer value (when not set to 0). This alarm is most commonly
used to indicate an equipment maintenance interval is due. The supply fan runtime accumulator may be reset
by setting the Maintenance > Reset Supply Fan Runtime Alarm to Clear, and then back to Run –
acknowledging each selection by clicking the OK button when it appears. Setting Unit Configuration > Supply
Fan Service Timer value to 0 disables the supply fan runtime alarm function.
Compressor 1 Runtime - The RTU Open generates this alarm when the accumulated runtime exceeds the
Unit Configuration > Compressor 1 Service Alarm Timer value (when not set to 0). This alarm is most
commonly used to indicate an equipment maintenance interval is due. The Compressor 1 Runtime
accumulator may be reset by setting the Maintenance > Reset Comp 1 Runtime Alarm to Clear, and then
back to Run – acknowledging each selection by clicking the OK button when it appears. Setting Unit
Configuration > Compressor 1 Service Timer value to 0 disables the Compressor 1 Runtime alarm function.
Compressor 2 Runtime - The RTU Open generates this alarm when the accumulated runtime exceeds the
Unit Configuration > Compressor 2 Service Alarm Timer value (when not set to 0). This alarm is most
commonly used to indicate an equipment maintenance interval is due. The Compressor 2 runtime
accumulator may be reset by setting the Maintenance > Reset Comp 2 Runtime Alarm to Clear, and then
back to Run – acknowledging each selection by clicking the OK button when it appears. Setting Unit
Configuration > Compressor 2 Service Timer value to 0 disables the Compressor 2 runtime alarm function.
Note that this function is unavailable if the Service Configuration > Compressor States value is not set to Two
Stages .
Filter - The RTU Open generates this alarm when the accumulated runtime exceeds the Unit Configuration >
Filter Service Alarm Timer value (when not set to 0). This alarm is most commonly used to indicate a filter
replacement is due. Reset the filter service runtime accumulator by setting the Maintenance > Reset Filter
Runtime Alarm to On, back to Off, and clicking the OK button after each setting. Setting Unit Configuration >
Filter Service Alarm Timer value to 0 disables the filter service alarm function.
Airside Linkage Alarm - An RTU Open may act as an air source in a zoned system. Carrier systems utilize a
function called Linkage™ to pass data between a master zone and its air source via an MS/TP network
connection. When the RTU Open is part of a linked system, it will indicate an airside linkage alarm if it loses
communications with its linkage master or if it receives invalid data.
Linkage
The RTU Open may serve as an air source to an Open Variable Volume Terminal (VVT) system. When the RTU
Open is part of a VVT system and the controllers are wired together to form a network, the controllers may use
a method of communication known as Linkage™. Linkage is a method by which an air source and its
subordinate zone terminals exchange data to form a coordinated HVAC system. The system's air source
controller, zone controllers, and bypass controller are linked so that their data exchange can be managed by
one zone controller configured as the VVT Master.
The VVT Master gathers the following information from the slave zone controllers:
•
occupancy status
• setpoints