Trane Ascend ACR C Series User Manual

88
AC-SVX003A-EN
Full Load to Minimum Load
The following diagram shows the normal transition from full
load to minimum load while the chiller is running.
Figure 34. Sequence of events: full load to minimum load
Running
(All
Compressors
& Max
Capacity)
All Compressors Running At
Less Than Max Capacity
De-Energize the
Maximum Capacity
Relay after
Adjustable Filter
Time (0 to 600 Sec)
Remove Maximum
Capacity Submode
RunningRunning
StageOff Setpoint Met
***
Running
Lag Circuit Mode: Shutting Down
SubMode: Operational Pumpdown
*
Running
Lag Circuit Mode: Shutting Down
SubMode: Operational Pumpdown
*
Operational Pumpdown
(0 Seconds to
Max Pumpdown Timer(Default: 2 min.))
Fully Close EXV
Close Condenser
Rfgt Tank Solenoid
Valve
IF*
No Pumpdown Required
Pumpdown
Required
Close EXV
(0 to 25 Seconds)
Normal Pumpdown Termination
**
Criteria is Met for Last Circuit
Send Stop
Command To Lag
Compressor
Continue to Control Capacity
by Modulating Compressor
Capacity
*** Note: The decision to stage off another compressor is determined by the
Average Running Compressor Load Command, Water Temperature Error,
and Time since Last Stage. Compressors will stage off in the reverse order
they staged on. All fixed speed compressors will stage off before variable
speed compressors stage off.
On a manifolded circuit, GP4 will be the first to start and last to stop; GP2
will not run by itself.
Stop Lag Circuits
Condenser Fans
Energize Lag
Circuit Heaters
Running
Lag Circuit Mode: Auto
Running
Lag Circuit Mode: Auto
Continue to Control
Capacity by Modulating
Lead Compressor
Running Last
Compressor at
Min Capacity
RunningRunning
Enforce All Running
Mode Diagnostics
Enforce All Running
Mode Diagnostics
Enforce All Non Operational Pumpdown
Diagnostics
Enforce All Non Operational Pumpdown
Diagnostics
Enforce Running Mode Diagnostics for Chiller,
Last Compressor and its Circuit
Enforce Running Mode Diagnostics for Chiller,
Last Compressor and its Circuit
Check for Normal
Pumpdown Termination
Criteria Met
**
Check for Normal
Pumpdown Termination
Criteria Met
**
Running
(All
Compressors
& Max
Capacity)
All Compressors Running At
Less Than Max Capacity
De-Energize the
Maximum Capacity
Relay after
Adjustable Filter
Time (0 to 600 Sec)
Remove Maximum
Capacity Submode
Running
StageOff Setpoint Met
***
Running
Lag Circuit Mode: Shutting Down
SubMode: Operational Pumpdown
*
Operational Pumpdown
(0 Seconds to
Max Pumpdown Timer(Default: 2 min.))
Fully Close EXV
Close Condenser
Rfgt Tank Solenoid
Valve
IF*
No Pumpdown Required
Pumpdown
Required
Close EXV
(0 to 25 Seconds)
Normal Pumpdown Termination
**
Criteria is Met for Last Circuit
Send Stop
Command To Lag
Compressor
Continue to Control Capacity
by Modulating Compressor
Capacity
*** Note: The decision to stage off another compressor is determined by the
Average Running Compressor Load Command, Water Temperature Error,
and Time since Last Stage. Compressors will stage off in the reverse order
they staged on. All fixed speed compressors will stage off before variable
speed compressors stage off.
On a manifolded circuit, GP4 will be the first to start and last to stop; GP2
will not run by itself.
Stop Lag Circuits
Condenser Fans
Energize Lag
Circuit Heaters
Running
Lag Circuit Mode: Auto
Continue to Control
Capacity by Modulating
Lead Compressor
Running Last
Compressor at
Min Capacity
Running
Enforce All Running
Mode Diagnostics
Enforce All Non Operational Pumpdown
Diagnostics
Enforce Running Mode Diagnostics for Chiller,
Last Compressor and its Circuit
Check for Normal
Pumpdown Termination
Criteria Met
**
* & ** Operational Pumpdown Requirement and Termination - See
Satisfied Setpoint Operational Pumpdown sequence diagram for
specific criteria.
Perform Operational
Pumpdown for Last
Circuit if Required
*
Start-up and Shutdown

Trane Ascend ACR C Series Specifications

General

Brand	Trane
Model	Ascend ACR C Series
Category	Chiller
Language	English