The STS900 chiller

The STS900 chiller

Dometic chiller role for valve

The chiller technology, such as variable frequency drive, PLCs and electronic expansion valves, ensures optimal operation under any conditions

March 2015

An electronic expansion valve plays an important role in a smart chiller that Dometic has been contracted to supply Trinity Yachts.

The high-capacity Dometic STS900 chiller for Trinity’s TO62 vessel, a 194-foot superyacht, is state of the art for yachts up to 200 feet, providing 75 tonnes of cooling capacity and 75 kilowatts of heat. It offers advanced features to adjust to extreme seawater temperatures, regulate water flow through the system, reduce stress on the boat generator, simplify maintenance and ensure optimal operation.

Dometic engineers worked closely with Trinity Yachts to design the chiller to the company’s precise specifications. The chiller comes with a touch-screen display that is customisable to Trinity Yachts. It offers remote connectivity out of the box, with complete access from smart phones, tablets and computers. Technicians can use the remote connectivity to control, diagnose and troubleshoot the chiller.

“The STS900 is an ideal system for our superyacht customers who voyage to extremely hot climates as well as to cooler temperatures. It offers a high level of visibility and control, with a design that will maximise operation and minimise maintenance,” said Billy S. Smith III, vice president of sales and marketing at Trinity Yachts. “We are delighted to be addressing our clients’ needs not only with this chiller implementation, but also with Dometic’s extended product line of HVAC and Livos engine ventilation equipment.”

“The STS900 is a smart chiller that provides yacht owners, their captains and technicians with advanced technology – such as a variable frequency drive, programmable logic controllers and electronic expansion valves – to ensure optimal operation under any conditions. Yacht owners and their passengers will be cool on the hottest days and warm when the weather chills – regardless of where they are travelling,” said Ed Todd, director of OEM sales at Dometic Marine. “Superyacht customers with this smart chiller can now rely on Dometic for their complete heating, cooling and engine ventilation needs.”

The STS900 offers the following features:

Optimal operation under varying conditions. The STS900’s Programmable Logic Control allows the chiller to operate optimally given a range of seawater conditions – from the hottest seas in the Middle East to the chilliest Atlantic waters.

Smooth startup. The system’s Variable Frequency Drive slowly ramps up the compressor for a smooth startup, without stressing the vessel’s generator. The VFD is completely bypassable.

Reduced electronic noise. Once the compressor starts operating, the bypassable VFD shuts off so it doesn’t generate electronic noise on-board the vessel.

Closed loop monitoring. The chiller has a closed loop monitoring system to measure electrical current and pump operation, ensuring optimal operation.

Electronic expansion valve. The electronic expansion valve, which utilises the Programmable Logic Controller, optimises operation across a wide range of conditions, with less need for human intervention.

Flow control. The chiller regulates water flow through unit, protecting and extending the life of the condensers during normal service and maintenance. Isolation valves can be used for cleaning.

Load shedding. The Programmable Logic Controller, based on inputs from the vessel’s switchboard panel, sheds items of high electrical consumption when they are about to max out on power (whether shore or generator). The reduction in compressor use from three compressors to two or one, prevents overloading the ship’s system, which can lead to blackouts.

Erosion-Corrosion prevention. Each condenser has a dedicated strainer located just before the condenser. Seashells sometimes grow downstream of the main strainer, and then break off and lodge in the condenser, causing failure. These serviceable Y-strainers are a backup to protect the condensers from such debris. Moreover, a special, proprietary anode provides added protection against corrosion.

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