80
CVHE-SVX005C-EN
Figure 57. Sequence of operation: normal shut-down to stopped and run inhibit
Local Stop
Normal Latching Diagnostic
Normal Non-Latching Diagnostic
Tracer Stop
External Auto-Stop
Preparing Shutdown Shutting Down Shutting Down
IGV Closed
Evaporator
Pump Off
Delay and
Postlube
Completed
Stopped
Run Inhibit
Stopped
or
Run Inhibit
Running
Close IGV (0 to 50 seconds) Postlube
(CVH: 3 minutes)
(CVG: 1 minute)
Command IGV Closed
Enforce All Running Mode Diagnostics
De-Energize Condenser
Water Pump Relay
De-Energize
Compressor
De-Energize Oil Pump
De-Energize Evaporator
Water Pump Relay
Evaporator Pump Off Delay Time
(0 to 30 minutes)
Confirm No Compressor Currents
Within 8 seconds
Confirm No Oil Press*
5 minutes After Oil Pump
is De-Energized
*Note: CVH: No oil pressure is less than 3 psid (20.7 kPaD)
CVG: No oil pressure is opened Oil Differential Pressure Switch
Power Up
“Software Operation Overview Diagram,” p. 75 includes an
illustration of Tracer
®
Symbio 800 during a power up of the
controller. This process takes up to 15 seconds, depending
on the number of installed options.
Ice Building Control
The control panel provides a service level Enable or
Disable menu entry for the Ice Building feature when the
Ice Building option is installed. Building can be entered
from Front Panel or, if hardware is specified, the control
panel will accept either an isolated contact closure 1A19
Terminals J2-1 and J2-2 (Ground) or a remote-
communicated input (BAS) to initiate the Ice Building mode
where the unit runs fully loaded at all times. Ice Building will
be terminated either by opening the contact or based on
entering evaporator fluid temperature. The control panel
will not permit the Ice Building mode to be entered again
until the unit is switched to the non-ice building mode and
back into the ice building mode. It is not acceptable to reset
the chilled water setpoint low to achieve a fully loaded
compressor. When entering Ice Building, the compressor
will be loaded at its maximum rate and when leaving Ice
Building, the compressor will be unloaded at its maximum
rate. While loading and unloading the compressor, all surge
detection will be ignored. While in the ice building mode,
demand limit setpoints less than the maximum will be
ignored. Ice Building can be terminated by one of the
following means:
• Front panel disable
• Opening the external ice contacts/remote-
communicated input (BAS)
• Satisfying an evaporator entering fluid temperature
setpoint (default is 27°F [-2.8°C])
• Surging for seven minutes at full open inlet guide vanes
(IGV)
Start-Up and Shutdown
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