AC-SVX002C-EN
51
Table 24.
Operating modes — circuit (continued)
Circuit Modes
Description
External Circuit Lockout
The respective circuit is manually locked out by External Circuit Lockout switch.
Remote Circuit Lockout
The respective circuit is manually locked out by a BAS Remote Circuit Lockout command.
Auto
The circuit is not currently running but can be expected to start at any moment given that the
proper conditions are satisfied.
Calibrating EXV
This submode is displayed when the circuit EXV is performing a calibration. A calibration is
only performed when the chiller is not running and never more frequently than once every 24
hours (note, this mode can occur in other nonrunning top level circuit modes) but shown
here as the most likely.
Waiting to Start
The circuit is going through the necessary steps to allow the lead circuit to start.
Running
The compressor on the given circuit is currently running.
Part-Load Efficiency Optimization
The circuit has part-load efficiency optimization that is active. Condenser fan speed will be
decreased while evaporator capacity is held constant to improve unit EER.
Running - Limit
The circuit, and compressor are currently running, but the operation of the chiller/
compressor is being actively limited by the controls. Further information is provided by the
sub-mode.* See the section below regarding criteria for annunciation of limit modes
Hot Start Limit
Additional stages on a given circuit are being held off based on leaving evaporator
temperature.
Condenser Pressure Limit
The circuit is being inhibited from loading due to high discharge pressure. (aka Condenser
Pressure)
Low Suction Pressure Limit
The circuit is being inhibited from loading due to low suction pressure.
High Discharge Temp Limit
The circuit is being inhibited from loading due to high discharge temperature.
Compressor Involute Pressure Limit
The circuit is being inhibited from loading due to high compressor involute pressure
differential.
Preparing Shutdown
The circuit is preparing to de-energize the compressor.
Operational Pumpdown
The operational pumpdown is enabled and the circuit is shutting down.
Shutting Down
The chiller is going through the necessary steps after de-energizing the compressor.
Miscellaneous
These submodes may be displayed in most of the top level circuit modes.
Next Defrost Allowed In: MIN:SEC
The circuit recently defrosted, but is not being allowed to defrost again until the timer
elapses, even if other criteria for defrost have been met.
Service Pumpdown
The circuit is currently performing a service pumpdown.
Compressor X Running
A specific compressor is running where X is A, B, or C.
Restart Time Inhibit Cprsr X: MIN:SEC
If there is accumulated Restart Inhibit Time, it must expire before the compressor is allowed
to start. X is denoted as compressor A, B, or C.
Warm-Up Cycle
This circuit is in a warm-up cycle operating mode
Waiting for Warm-Up Cycle
This circuit is in waiting for a warm-up cycle. Has met the criteria for a warm-up cycle but is
not allowed to start.
Defrosting
The circuit is in a de-frost operational mode.
Waiting for Defrost
This circuit is in waiting for defrost. Has met the criteria for defrost but is not allowed to start.
Manual Defrost Request
User has commanded a manual defrost cycle.
Compressor X Locked Out
Compressor X (A, B, or C) is manually locked out by its respective compressor lockout setting
– the nonvolatile lockout setting is accessible through either the DynaView or TechView.
