• Smart Investment – lower total cost of ownership over the life of the chiller due to reduced energy and maintenance costs
• Highly Efficient – designed to achieve real-world energy operation by utilizing industry-leading low entering condenser water temperatures, the YMC ²can offer as low as 0.175 kW/ton at full capacity and below 0.1 kW/ton at part load

• Versatile – offers widest operating range to meet the needs of various applications

• Strongly Dependable – fully integrated YORK chiller design provides reliable operation and lower maintenance

• Very Low Sound Levels – quieter than a household vacuum cleaner, the YMC² achieves sound levels as low as 70 dBA

YORK® Navy Systems of Johnson Controls is dedicated
to providing superior HVAC&R systems for warships
and support ships of multiple fleets. Because you can’t
just open a window in these vessels, one of the biggest
concerns for naval HVAC applications is reliability.
Crews and their sensitive electronic equipment need
first-class air-conditioning to stay cool in close quarters.
YORK® Navy Systems has supplied chillers with magnetic-bearing technology for over 115 critical naval applications, with many of
them being nuclear submarines.
(Crédit photo DCNS)
In 1998, YORK Navy Systems pioneered an innovative,
magnetic-bearing technology for the centrifugal chillers
used in onboard cooling plants. By offering this technology,
YORK Navy Systems was able to provide quiet, safe,
and reliable cooling for one of the most difficult
environments on earth. Now we are introducing
this technology for commercial chillers

The Quick Start feature - designed
for your critical applications
Temperature sensitive operations such as data centers,
pharmaceutical labs, hospitals, semiconductor production
and other manufacturing facilities require constant cooling
for equipment and processes. If power fails and cooling is
interrupted, critical operations may also fail – risking millions
of dollars in equipment failure and operational downtime.
The Quick Start feature reduces the risk of
cooling disruption
Standard on all YMC² magnetic bearing centrifugal chillers, the
Quick Start feature saves both time and money by:
• Reducing time for chiller restart after a power failure
• Rapidly bringing the chiller back to pre-power
failure operating capacity
• Keeping critical space and equipment cooled
• Reducing the risk of expensive downtime
Smarter Power Management, Faster Restarts
After power is interrupted, it can take a standard centrifugal
chiller many minutes to restart. But YMC² chillers can restart
within 45 seconds after power is restored from a 15 second
or shorter power failure. During a power failure, the Magnetic
Bearing Controller, OptiView™ Panel, and OptiSpeed™
variable speed drive control circuits remain energized until the
facility’s emergency generator is activated. This smart power
management eliminates the need for a control panel reboot so
that the chiller can restart within 45 seconds of power being
restored

The fastest capacity recovery in the
industry
Not only will your YMC² chiller restart quickly, more
importantly, your chiller will return to its original
operating conditions quickly, ensuring your facility
does not lose precious products or services. YMC²
chillers can get back to pre-power failure operating
capacity within 3 minutes and 30 seconds.*
The YMC² YORK centrifugal chiller offers significantly
faster capacity recovery times compared to the
industry’s typical centrifugal chiller. For your critical
cooling application, consider a YMC² chiller that can
return your facility to 100% capacity faster than any
other chiller.
There are several factors that can alter or improve the
times of a chiller with the Quick Start feature:
• Specific chiller configuration
• Percent capacity operation prior to power failure
• Length of the power failure
A performance test can be requested to witness
restart times and capacity recovery times for your
specific chiller, capacity operation, and length of power
failure. Performance tests, requested in advance, are
held at the Johnson Controls Water-Cooled Chiller
Performance Test Facility and Customer Center in
San Antonio, TX alongside our Water-Cooled Chiller
Manufacturing Facility.
Proven Performance
With an ever-growing number of centrifugal chillers with Quick Start installed around the world, you receive peace of mind
knowing your chillers – and your operation – can be protected by Johnson Controls from the consequences of a power failure.
For details on a YMC2 chiller with the Quick Start feature, or to learn more about other Quick Start feature offerings, contact your
local Johnson Controls branch today, or visit www.johnsoncontrols.com/chillers.
*Standard on most YMC2 chillers, optional on a few lower capacity models.

SYSTEM COMPONENTS
The YORK Model YMC2 Centrifugal Liquid Chiller is completely factory-packaged including evaporator, condenser, compressor, motor, OptiViewTM Control Center, and all interconnecting unit piping and wiring (see Figure 1).
Compressor
The compressor is a single-stage centrifugal type powered by a hermetic electric motor, on a common shaft with a cast aluminum, fully shrouded impeller. The impeller is designed for balanced thrust and is dynamically balanced and over-speed tested. The compressor model number includes gas path revision level at the end of the model string. Gas path revision level A includes pre-rotation vanes. Gas path revisions B has fixed inlet vanes.
Motor
The compressor motor is a hermetic permanent magnet high speed design with magnetic bearings. The compressor impeller is overhung from the end of the motor shaft and has no bearings of it's own.
The motor includes angular contact ball bearings only for control of the rotor during shutdown after rotation is stopped or during shutdown due to loss of power to the magnetic bearings.
The bearing control center maintains proper shaft position in the magnetic bearings and counts events where the touchdown ball bearings may have been contacted during shaft rotation to alert the operation where a bearing check may be necessary. The condition of the touchdown bearings can be assessed by qualified service technicians electronically without opening the unit.
Ensure power is removed
from the input side of the VSD at all times when the chiller is under vacuum (less than atmo-spheric pressure). The VSD maintains voltage to ground on the motor when the chiller is off while voltage is available to the VSD. Insulating properties in the mo-tor are reduced in vacuum and may not insulate this voltage sufficiently

Heat Exchangers
Evaporator and condenser shells are fabricated from rolled carbon steel plates with fusion welded seams. Heat exchanger tubes are internally enhanced type.
Evaporator
The evaporator is a shell and tube, hybrid falling film, and flooded type heat exchanger. A distributor trough provides uniform distribution of refrigerant over tubes in the falling film section. Residual refrigerant floods the tubes in the lower section. Suction baffles are located above the tube bundle to prevent liquid refrigerant carryover into the compressor. A 2" liquid level sight glass is located on the side of the shell to aid in determining proper refrigerant charge. The evaporator shell contains dual refrigerant relief valves unless condenser isolation is installed.
Condenser
The condenser is a shell and tube type, with a discharge gas baffle to prevent direct high velocity impingement on the tubes. A separate subcooler is located in the condenser to enhance performance. Dual refrigerant relief valves are located on condenser shells and optional refrigerant isolation valves are available.
Water Boxes
The removable compact water boxes are fabricated of steel. The design working pressure is 150 PSIG (1034 kPa) and the boxes are tested at 225 PSIG (1551 kPa). Integral steel water baffles provide the required pass arrangements. Stub-out water nozzle connections with Victaulic grooves are welded to the water boxes. These nozzle connections are suitable for Victaulic couplings, welding or flanges, and are capped for shipment. Plugged 3/4" drain and vent connections are provided in each water box. Optional marine waterboxes are available.
Refrigerant Flow Control
Refrigerant flow to the evaporator is controlled by a variable orifice (refer to Figure 3).
A level sensor senses the refrigerant level in the condenser and outputs an analog voltage to the Microboard that represents this level (0% = empty; 100% = full). Under program control, the Microboard modulates a variable orifice to control the condenser refrigerant level to a programmed setpoint. Other setpoints affect the control sensitivity and response. These setpoints must be entered at chiller commissioning by a qualified service technician. Only a qualified service technician may modify these settings.
While the chiller is shut down, the orifice will be pre positioned to anticipate run. When the chiller is started, if actual level is less than the level setpoint, a linearly increasing ramp is applied to the level setpoint. This ramp causes the setpoint to go from the initial refrigerant level to the programmed setpoint over a programmable period of time. If the actual level is greater than the setpoint upon run, there is no pulldown period, it immediately begins to control to the programmed setpoint.
While the chiller is running, the refrigerant level is normally controlled to the level setpoint.
Optional Service Isolation Valves
If your chiller is equipped with optional service isolation valves on the discharge and liquid line, these valves must remain open during operation. These valves are used for isolating the refrigerant charge in either the evaporator or condenser to allow service access to the system. A refrigerant pump-out unit will be required to isolate the refrigerant.
Isolation of the refrigerant in this system must be performed by a qualified service technician.
Optional Hot Gas Bypass
Hot gas bypass is optional and is used to provide greater turndown than otherwise available for load and head conditions. The OptiViewTM Control Center will automatically modulate the hot gas valve open and closed as required. Adjustment of the hot gas control valve must only be performed by a qualified service technician.
OptiViewTM Control Center
The OptiViewTM Control Center is factory-mounted, wired and tested. The electronic panel automatically controls the operation of the unit in meeting system cooling requirements while minimizing energy usage. For detailed information on the Control Center, refer to the YMC2 OptiViewTM Control Center Operations Manual (Form 160.78-O2).

Variable Speed Drive
A Variable Speed Drive will be 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 drive also supplies DC power to the motor magnetic bearing controller for bearing operation. Operational information is contained in the OptiSpeed VSD Operation Manual (Form 160.78-O3). The control logic automatically adjusts motor speed and compressor prerotation vane position for maximum part load efficiency by analyzing information fed to it by sensors located throughout the chiller.
SYSTEM OPERATION DESCRIPTION
The YORK Model YMC2 Chiller is commonly applied to large air conditioning systems, but may be used on other applications. The chiller consists of a hermetic motor mounted to a compressor, condenser, evaporator and variable flow control.
The chiller is controlled by a modern state of the art Microcomputer Control Center that monitors its operation. The Control Center is programmed by the operator to suit job specifications. Automatic timed start-ups and shutdowns are also programmable to suit nighttime, weekends, and holidays. The operating status, temperatures, pressures, and other information pertinent to operation of the chiller are automatically displayed and read on a graphic display. Other displays can be observed by pressing the keys as labeled on the Control Center. The chiller with the OptiViewTM Control Center is compatible with the Variable Speed Drive.
In operation, a liquid (water or brine to be chilled) flows through the evaporator, where boiling refrigerant absorbs heat from the liquid. The chilled liquid is then piped to fan coil units or other air conditioning terminal units, where it flows through finned coils, absorbing heat from the air. The warmed liquid is then returned to the chiller to complete the chilled liquid circuit.
The refrigerant vapor, which is produced by the boiling action in the evaporator, flows to the compressor where the rotating impeller increases its pressure and temperature and discharges it into the condenser. Water flowing through the condenser tubes absorbs heat from the refrigerant vapor, causing it to condense. The condenser water is supplied to the chiller from an external source, usually a cooling tower. The condensed refrigerant drains from the condenser into the liquid return line, where the variable orifice meters the flow of liquid refrigerant to the evaporator to complete the refrigerant circuit.
The major components of a chiller are selected to handle the required refrigerant flow at full load design conditions. However, most systems will be called upon to deliver full load capacity for only a relatively small part of the time the unit is in operation. A means exists to modulate capacity for other loads.
CAPACITY CONTROL
The speed at which the compressor rotates establishes the pressure differential that the chiller can operate against. As speed is reduced, the chiller power use is reduced. At reduced capacity requirements where condenser pressure is also reduced, the motor speed is reduced as much as possible while maintaining chilled water temperature and sufficient pressure differential. When the speed cannot be further reduced due to pressure difference required for the specified leaving chilled water temperature setting and available cooling to the condenser, other means to reduce refrigerant gas flow are used to manage capacity. Compressor models M1B-197FAA and M1B-205FAA use a device called prerotation vanes (PRV) at the entrance to the impeller to reduce capacity (See Figure 2). Regardless of chiller compressor model, the chiller also has a mechanism called Variable Geometry Diffuser (VGD) at the exit of the impeller that was designed to mitigate “stall”. Stall is an effect caused by slow refrigerant gas

York (Wuxi) air Conditioning and Refrigeration Co. Ltd, Located in Wuxi National High-tech Industrial Park, Jiangsu province, China. Covers an area of 60000 square meters, of which the heavy machine factory building takes up 14,000 square meters. At present, the company has about 500 staffs, in the field of large-size units. York Wuxi is the largest manufacturer in Asia –pacific region with an annual output of more than 3600 sets. Its products not only top on market share in China, but also see tremendous growth in export in recent years.

York Wuxi has six production lines in total, of which five are automated lines, including one air-cooled screw production line, one large-size water-cooled screw unit production line, one small-size water-cooled screw unit production line, and two centrifugal unit production line. All production line adapt the DFT technology, being the first in the industry. The entire work process is compact and rational. With the efficient management method (such as four-color light), these lines have become the most compact, most efficient and most advanced production line in the industry.

York Wuxi is equipped with globally advance equipment in every step of its production process, including:

Most advanced plasma digital cutter which can be used under water

Efficient digital plate bending machine with a roll length up to 4.8 meters

LINCO DC submerged arc welder imported from USA which is the most advanced equipment in the world.

Most advanced digital drill press in the industry.

Four large-sized chiller comprehensive performance test branches, (test capacity per set up to 2000 cold tons, for 10KV high voltage tests and frequency conversion tests), presenting the most advanced level in China.

YORK (CHINA) introduced the Performance Excellence Mode since the beginning of its operation. This mode adopted by most world-class enterprises focuses on the customers. It learns, meets and exceeds the customers’ needs and serves society through its human-oriented strategy and corporate culture. Based on the effective QEHS management system and advanced management tools (e.g. six-sigma).YORK (CHINA) consolidates its leading status in the industry.

1.   YORK RESEARCH AND DEVELOPMENT

In December 2004, to provide high-quality and competitive air conditioning products and refrigeration equipments to the Asia-Pacific region and on the parts of the world, YORK set up the YORK Asia Pacific research and development center in

Wuxi.

The center has the most advanced software systems, highly qualified professionals, and various test equipments and systems. The air-cooled test bench, unique in China and the largest in the

Asia-Pacific region, which has complete spring base for the equipment vibration test, can lower the noise to 20db by means of muffle devices. It also can carry out the working environment temperature simulation test by changing the indoor temperature via air conditioning and refrigeration system.

Since its establishment, the R&D center is dedicated to development efficient, energy saving, environment friendly products with independent intellectual property and unique technology and to the research of thermal conductivity, noise vibration and reliability to meet the needs of refrigeration &air conditioning in China and even the entire Asia-Pacific region. At the same time, the R&D center is also working closely with YORK international’s R&D division to develop money advanced products that can meet the global needs, In fact, innovation and renovation of many core technologies are happening in the Wuxi center.

2.   YORK SEVICES INTRODUCTION

York Air Conditioning & Refrigeration Service Centre was established in 1993 in Shanghai. The Service Centre is now having stations in Beijing, Nanjing, Guangzhou, Xiamen, Wuhan and Shenzhen, and service representatives in Shantou, Changsha, Chengdu, Jinan, Dalian, Harbin and Hangzhou, and so on. Using our established service center networks throughout China, we are able to provide full after-sales services to all our customers in China.

At the same time, the service center is having a bonded spare parts warehouse in Shanghai. The spare parts warehouse will serve the spare part needs for our customers with minimum delivery time.

Qinhao Zhan

HVAC&R Engineer

Refrigeration and Process Systems