System operating procedures
The following section provides information on pre-starting, start-up, and operation of the chiller.
Pre-starting
Before starting the chiller, make sure that the display shows the message SYSTEM READY TO
START. The panel can only start when line power is available to the VSD transformers and the UPS
battery in the power panel is present and connected with the battery disconnect switch closed.
WARNING
Never attempt to start the chiller until the temperature of the MBC and VGD enclosures are maintained
above 32°F (0°C).
CAUTION
After periods of waterside maintenance or prolonged shutdown, vent any air from the chiller water
boxes before starting the water pumps. Failure to do so can result in pass baffle damage.
Start-up
If the chilled water pumps are manually operated, start the pump. The control center does not
allow the chiller to start unless chilled liquid flow is established through the unit. If the liquid pumps
are wired to the microcomputer control center pump run contacts, the pump automatically starts
instead.
Note: The coolant temperature inside any liquid-cooled motor starter supplied by Johnson
Controls must be maintained above the dewpoint temperature in the equipment room
to prevent condensing water vapor inside the starter cabinet. An additional temperature-
controlled throttle valve is needed in the flow path for the starter heat exchanger to regulate
cooling above the equipment room dewpoint for applications using cooling sources other
than evaporative air-exchange methods, such as wells, bodies of water, and chilled water. The
temperature control valve must be the type to open on increasing drive coolant temperature,
fail-closed, and set for a temperature above dewpoint. You can request the valve as factory-
supplied on a chiller order by special quotation.
The start/stop control depends on the control source selected on the chiller Setup > Remote
Control screen. Start is operated under the following conditions:
• Only the keypad when the chiller is set to local control
• Remotely through hardwired contacts, but the local keypad start must be pressed initially to
enable the run permissive
• By the SC-EQUIP in BAS control, but the local keypad start must be pressed initially to enable the
run permissive
To start the chiller, press the start button on the home screen on the display panel. In local control
source, the chiller then starts. When the run/stop control is set to BAS or hardwire, a remote start
command must also be provided to the correct input connection.
31YVAM with OptiView Control Center
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