Johnson Controls YORK YVAM 0350, Operation & Maintenance Manual

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Variable speed drive
The variable speed drive is factory packaged with the chiller. It is designed to vary the compressor
motor speed by controlling the frequency and voltage of the electrical power to the motor. The
control logic automatically adjusts motor speed as required to suit lift and capacity requirements.
Power panel
The power panel includes the uninterrupted power supply and power storage battery. These work
together to feed essential electrical loads if the chiller shuts down due to the loss of main chiller
power.
Optional service isolation valves
Optional service isolation valves include two on the discharge lines to each condenser section
and one on the liquid line to the evaporator. If your chiller is equipped with these optional service
isolation valves, they must remain fully open during operation. These valves are used for isolating
the refrigerant charge in the condenser to allow service access to the evaporator and compressor
side of the system. A refrigerant recovery unit is required to isolate the refrigerant.
CAUTION
Isolation of the refrigerant in this system must be performed by a qualified service technician.
YVAM Control Center 14