AC-SVX001A-EN
55
Table 19. Operating modes — chiller (continued)
Chiller Modes
Description
Cold Ambient Start Inhibit – Waiting for
Warmer Water
During startups with Outdoor Ambient temperatures less than 18°F, it may be necessary to
require warmer entering water to avoid a freeze danger at startup. The occurrence of this
mode suggests that startup is being inhibited pending warmer water temperatures than
otherwise would be required by the Differential to Start and Active Chilled Water
Temperature settings.
Running At least one circuit on the chiller is currently running.
Chilled Water Control
Chiller is running to provide a chilled water temperature per the active chilled water setpoint
(may be as arbitrated from various sources). (For cooling only units, this mode may be
suppressed.)
Maximum Capacity The chiller is operating at its maximum capacity.
Capacity Control Softloading The control is limiting the chiller loading due to capacity based softloading setpoints.
Demand Limit Softloading
The chiller is running, and loading of individual compressors may be limited by a gradual
filter of the chiller’s softloading Demand Limit setpoint. The starting Demandlimit and the
settling time of this filter is user adjustable as part of the Demand control softload feature.
The mode will be displayed as long as the Demand Control Softloading limit is ramping or
“settling”.
Shutting Down
The chiller is still running but shutdown is imminent. The chiller is going through a
compressor run-unload or extended operational pumpdown of the lag circuit/compressor (or
all circuits simultaneously)
Evaporator Water Pump Off Delay: MIN:SEC
The Evaporator water pump is continuing to run past the shutdown of the compressors,
executing the pump off delay timer.
Various
These submodes may be displayed in most of the top level chiller modes.
Manual Evap(orator) (Water) Pump Override The Evaporator water pump relay is on due to a manual command.
Diagnostic Evap (Water) Pump Override The Evaporator water pump relay is on due to a diagnostic.
Waiting for BAS Communications
The chiller has not detected communication with the BAS. This mode is only supported by
LonTalk systems. Depending on configurations and Setpoint source setting, lack of
communication may cause the chiller to shut down and or become inhibited from starting,
but if so, the “Starting is Inhibited by BAS” mode will also occur.
Manual Compressor Control Signal Chiller capacity control is being controlled by AdaptiView or TU.
Noise Reduction
The Chiller’s Noise Reduction Mode has been activated. The condenser fans may be limited to
a lower speed than design, to reduce fan noise.
Chilled Water Control
These modes are mutually exclusive and they
indicate that the chiller is controlling to the
active hot water setpoint, the active chilled
water setpoint, or the active ice termination
setpoint respectively.
Ice Building
Note: Mode strings may or may not include the characters in parentheses.
Table 20. Operating modes — circuit
Circuit Modes
Description
Stopped The circuit is not running, and cannot run without intervention.
Diagnostic Shutdown – Manual Reset The circuit has been shutdown on a latching diagnostic.
Front Panel Circuit Lockout
The circuit is manually locked out by the circuit lockout setting – the nonvolatile lockout
setting is accessible through either the AdaptiView or TU.
External Circuit Lockout
The respective circuit is locked out by the external circuit lockout binary input.
Service Pumpdown The circuit is currently performing a service pumpdown.
CCoonnttrroollss
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