Microprocessor Controls

FORM 201.24-EG1

The Power and Control Panel shall be divided into a power section for each electrical system, a common input sec- tion and a control section.

Each power panel shall contain:

Compressor starting contactors, control circuit serving compressor capacity control, compressor contactor coils and compressor motor overloads. The compressor motor overloads contain current trans- formers which sense each phase, as an input to the microprocessor, to protect the compressor motors from damage due to: low input current, high input cur- rent, unbalanced current, single phasing, phase reversal, and compressor locked rotor.

The common input section shall contain:

The control supply transformer providing 115V, cus- tomer relay board and control circuit switch discon- nect/emergency stop device.

The control section shall contain:

On/Off rocker switch, microcomputer keypad and dis- play, microprocessor board, I/O expansion board, relay boards, and 24V fused power supply board.

Fuzzy Logic control will be incorporated in the YCWS range of chillers. Fuzzy Logic allows the control system to monitor several key variables to provide tighter, more stable chilled water temperature control. The control sys- tem monitors the leaving chilled water temperature to track where it has been, where it is now, how fast it is moving, and accurately adjusts the chiller operation in anticipation of expected performance to minimize hunt- ing and save energy.

The microprocessor shall have the following functions and displays:

•A liquid crystal 40 character display with text provided on two lines and light emitting diode backlighting for outdoor viewing.

•A color-coded, 35 button, sealed keypad with sec- tions for Display, Entry, Setpoints, Clock, Print, Pro- gram, and Unit On/Off Switch.

The standard controls shall include: brine chilling or ther- mal storage, automatic pumpdown, run signal contacts, demand load limit from external building automation sys- tem input, remote reset liquid temperature reset input, unit alarm contacts, chilled liquid pump control, automatic

reset after power failure, automatic system optimization to match operating conditions, software stored in non- volatile memory (EPROM) to eliminate chiller failure due to AC power failure.

The microprocessor can be directly connected to a YORK ISN Building Automation System via the standard on- board RS485 communications port. This option also pro- vides open system compatibility with other communica- tions networks.

Programmed Setpoints shall be retained in a lithium bat- tery backed RTC with a memory of five years.

Display - In Imperial (°F and PSIG) or SI (°C and BAR) units, and for each circuit:

•Return and leaving chilled liquid

•Day, date and time. Daily start/stop times. Holiday and Manual Override status.

•Compressor operating hours and starts. Automatic or manual lead/lag. Lead compressor identification.

•Run permissive status. No cooling load condition. Compressor run status.

•Anti-recycle timer and anti-coincident start timer sta- tus per compressor.

•Suction (and suction superheat), discharge, and oil pressures and temperatures per System.

•Percent full load compressor motor current per phase and average per phase. Compressor capacity con- trol valve input steps.

•Cutout status and setpoints for: supply fluid tempera- ture, low suction pressure, high discharge pressure and temperature, high oil temperature, low and high current, phase rotation safety, and low leaving liquid temperature.

•Unloading limit setpoints for high discharge pressure and compressor motor current.

•Liquid pull-down rate sensitivity (0.5°F to 5°F [0.3°C to 3.0°C]/minute in 0.1°F [0.05°C] increments).

•Status of: evaporator heater, load and unload timers, chilled water pump.

•Out of range message.

•Up to 6 fault shut down conditions.

•Standard Display Language is English, with an Op- tion for Spanish.

Entry - Enter set point changes, cancel inputs, advance day, change AM/PM.

Set Points - Chilled liquid temperature, chilled liquid range, remote reset temperature range.

Clock - Time, daily or holiday start/stop schedule, manual

YORK INTERNATIONAL

YCWS specifications

York YCWS, or York Chilled Water System, represents a revolutionary approach to modern commercial cooling solutions, offering efficiency, reliability, and sustainability. Designed specifically for large-scale applications such as industrial facilities, data centers, and office buildings, the York YCWS aims to optimize energy use while maintaining climatic comfort indoors.

One of the standout features of the York YCWS is its advanced chiller technology. Utilizing cutting-edge centrifugal chillers, the system maximizes cooling through a combination of high efficiency and low operational costs. These chillers operate with variable speed drives, allowing them to adjust their output based on the real-time cooling demand. This leads to significant energy savings, especially in fluctuating load conditions, and reduces wear on the equipment, extending its lifespan.

The YCWS also incorporates smart control systems that enhance its overall performance. These controls employ algorithms to anticipate system demands, dynamically balancing the load across multiple chillers and optimizing energy use throughout the day. Integration with building management systems (BMS) allows for seamless communication and remote monitoring, giving facility managers greater oversight and control over their cooling operations.

Sustainability is at the core of the York YCWS design. The system uses environmentally friendly refrigerants that comply with global standards for reducing greenhouse gas emissions. Additionally, the modular design of the chiller units allows for easy upgrades and expansions, accommodating growing cooling needs without necessitating a complete system overhaul. This flexibility supports a more energy-efficient and environmentally responsible operational model.

The system's footprint is relatively compact, allowing it to fit into tighter spaces typically found in urban settings. Furthermore, the YCWS is engineered for quiet operation, minimizing noise disturbances for occupants in and around the building.

Reliability is another key characteristic of the York YCWS. With a focus on durability and performance, these systems are built to function optimally in various environmental conditions. The robust construction and high-quality materials ensure long-term service, reducing the need for frequent maintenance and associated costs.

In summary, the York YCWS is not just a cooling solution but a comprehensive system that embodies modern engineering principles. Its efficiency, sustainability, and adaptability make it a preferred choice for industries looking to invest in their future. With its smart technologies and robust features, the York Chilled Water System is well-equipped to meet the demanding needs of today's commercial cooling challenges.