Johnson Controls YORK YVAM 0350, Operation & Maintenance Manual

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Drive operation
OptiSpeed compressor drive overview
The new YORK
®
OptiSpeed Compressor Drive (OSCD) is specifically designed for the application of
driving a permanent magnet high speed motor with magnetic bearings used on the YORK Model
YVAM Centrifugal Air-Cooled Chiller. This type of design allows the chiller to be designed as a
complete system, and take full advantage of the strengths of each major component within the
system. This method of design is a superior approach to using general purpose components off the
shelf that may not work well together.
This new OSCD design builds on the successes of previous designs of being chiller mounted,
provide for high levels of energy savings, great integration with the chiller control center, a sealed
liquid cooling system, plate and frame heat exchanger, use of fast switching power modules, high
reliability, and ease of service.
The following new features are included:
• Standard circuit breaker with ground fault detection
• Ground fault detection through the drive controls and communicated to the chiller control
panel
• Direct liquid cooling of power modules
• A more accessible cooling system
• Variable voltage input without step up or step down transformer required
• High speed direct drive motor
• The Harmonic filter is standard on all models
• Modular lighter weight power units that can be repaired in the field without complete
replacement
• Ease of maintenance and setup
• Enhanced protection with the Smart Sensor System
• NEMA 4 rated for outdoor applications
OptiSpeed compressor drive features
The new drive design is currently available in the following models: HYP0490B. This drive model
uses only one power assembly.
This drive model is able to determine a ground fault at much lower currents. The OSCD contains
three input current sensors that provide the information for the drive logic board to detect a
ground fault condition.
Direct liquid cooling is a much more efficient way of removing heat from the OSCD. This method
also reduces the cooling load on the internal air-cooling coil. In the past, YORK developed direct
liquid cooling for the inverter power modules, but today YORK is direct liquid cooling the rectifier,
inverter, input inductor, and the output inductor.
The cooling system for the OSCD is greatly modified to improve serviceability of the power
electronics. Repair of the power electronics no longer requires access to the back of the drive
except to drain the cooling system. A sealed cooling system nearly eliminates the need for cleaning
the cooling system. Also, the sealed cooling system means a longer coolant life and reduced
maintenance cost for replacement coolant.
111 YVAM Control Center