Low Voltage Optispeed Drive - York YK Manual

FORM 160.75-EG1 (519)
Accessories and Modifications (Cont'd)

LOW VOLTAGE OPTISPEED DRIVE

The Low Voltage OptiSpeed variable speed drive is factory-packaged and mounted on the
YORK YK chiller. It is designed to vary the compressor motor speed by controlling the
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frequency and voltage of the electrical power to the motor. The adaptive capacity control
logic automatically adjusts motor speed and compressor pre-rotation vane position inde-
pendently for maximum part load efficiency by analyzing information fed to it by sensors
located throughout the chiller.
The variable speed drive is mounted in a NEMA-1 enclosure with all power and control
wiring between the drive and chiller factory-installed. Electrical lugs for incoming copper
power wiring are provided.
The variable speed drive provides automatic displacement power factor correction to 0.95
or better at all load conditions. Separate displacement power factor correction capacitors
are not required. The displacement power factor is 0.98 or better when the optional har-
monic filter is provided. Additionally, variable speed drives have the following advantages:
• Lowest chiller life cycle through part load energy savings.
• Application-specific designs enable efficient, precise load control and seamless inte-
gration with equipment control panel and BAS.
• Soft start with input current less than full load current.
• Smooth acceleration reduces stresses on motor and driveline.
• Reduces compressor sound levels at most operating conditions.
• Rugged and reliable with no moving parts.
• IEEE-519 2014 compliant if used with an optional harmonic filter.
Standard features include: a door interlocked lockable circuit breaker; UL/cUL listed
ground fault protection; over-voltage and under-voltage protection; 3-phase sensing mo-
tor over-current protection; single-phase protection; insensitive to phase rotation; over-
temperature protection; digital readout at the OptiView™ Control Center of:
• Output Frequency
• Output Voltage
• 3-phase output current
• Input Power (kW)
• Self diagnostic service parameters
• Kilowatt-Hours (kWh)
28 JOHNSON CONTROLS