differential” value the controller will enable the compressor; if equipped with two compressors the controller will enable the one with the least amount of hours. The second compressor will be enabled if the leaving fluid temperature remains above the setpoint plus the “compressor on differential” value for more than 60 seconds.

The hot gas valve is designed to trim the load of one compressor and will modulate in order to meet the desired leaving fluid setpoint via a PID algorithm. After the compressor starts, the hot gas valve is allowed to modulate. The compressor will shut off if the leaving fluid temperature drops below the “compressor off differential” and the hot gas valve is at 100% for the “compressor off delay” time. The hot gas will reset to 0% when the compressor is off. There is a “compressor anticyle” timer that will delay the time between compressor starts to prevent short cycling of the compressor. This is a start to start timer set at 5 minutes. For example, if the compressor has been running for 5 minutes and shuts off, then the compressor can start immediately if the demand is there. If it has only been running for 2 minutes, then it would not be able to start again for 3 minutes.

For a unit with two compressors, the second compressor or lag compressor starts when the lead compressor is on, the hot gas is at 0%, and the leaving fluid temperature is above the setpoint plus the “compressor on differential”. There is also an adjustable “lag compressor on delay” timer. Before starting either compressor, the compressor with the least amount of runtime hours is considered the lead compressor and the first to start. When both compressors are running, the compressor with the most hours is considered the lead compressor and is the first to stop. The lead compressor will shut off if the leaving fluid temperature drops below the “compressor off differential” and the hot gas valve is at 100% for the “lead compressor off delay” time. The compressor anti-cycle timers are active with the two compressor units.

There will be two PID controls running simultaneously for determining the position of the hot gas valve. One PID output will be based on leaving fluid temperature and the other based on a minimum saturated suction temperature for freeze protection. The hot gas valve position will be determined by which output is greater. If it is controlling to the saturated suction temperature to prevent freezing, a warning will display on the screen that the hot gas is in this mode. Once the control goes back to setpoint control, the warning will disappear. The saturated suction temperature is calculated from the suction pressure and the type of refrigerant.

The discharge pressure is controlled using an analog output signal to drive a fan for air- cooled units or a water regulating valve for water-cooled units. The output signal is determined from a PID algorithm using a discharge pressure transducer as the process variable. The VFD or water regulating valve is controlled from the analog output to an adjustable discharge pressure setpoint. The analog output starts at the initial “discharge pressure start” % for a given time delay (discharge pressure hold). After the time delay, it will control to the discharge pressure setpoint via the PID control. There is also a setting to control the discharge pressure to the most efficient value.

2-3 Standard Features

Mechanical Features

Compressor – Hermetic scroll compressors.

Evaporator – Stainless steel copper brazed plate evaporators.

GP Series Portable Chillers

Chapter 2: Functional Description

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Sterling 882.93092.01 manual Standard Features, Mechanical Features
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882.93092.01 specifications

The Sterling 882.93092.01 is an impressive timepiece that exemplifies the perfect blend of artistry and precision engineering. This elegant watch is a testament to the craftsmanship that defines the Sterling brand, making it a sought-after choice for both watch aficionados and casual wearers alike.

One of the main features of the Sterling 882.93092.01 is its exceptional movement technology. This watch is powered by a reliable automatic movement, ensuring accurate timekeeping without the need for battery replacements. The self-winding mechanism harnesses the natural motion of the wearer's wrist, providing a seamless and hassle-free experience.

The design of the Sterling 882.93092.01 is another standout characteristic. The watch features a stainless steel case that provides durability and a sleek aesthetic. The polished finish adds a touch of sophistication, making it suitable for both formal and casual settings. With a diameter that fits comfortably on the wrist, it is designed for effortless wear throughout the day.

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Another notable aspect is the watch's water resistance. The Sterling 882.93092.01 is rated for water resistance, making it suitable for everyday wear, including light swimming and exposure to splashes. This feature enhances the watch’s practicality, allowing it to withstand the rigors of daily life without compromising its integrity.

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Overall, the Sterling 882.93092.01 is more than just a timekeeping device; it is a statement piece that showcases exceptional design, reliable technology, and outstanding craftsmanship. Whether worn at special occasions or in everyday scenarios, this watch is bound to impress and stand the test of time.
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