Electronic Refrigerator Controller Saves Energy and Reduces Costs
New commercial refrigerator controller can help OEMs save energy, reduce inventory and decrease installation time.
Behind every perfectly chilled beverage or frozen product stored in glass door merchandisers (GDMs) or commercial refrigerators and freezers is a small device-an electronic controller that manages a complex range of functions, from compressor operating times and canopy/cabinet lighting schedules to evaporator/condenser fan control and variable temperature control. Until recently, manufacturers of GDMs, and commercial refrigerators and freezers had two options when selecting a controller: a mechanical thermostat that offered no intelligence or an electronic controller with limited capabilities. Neither option could be applied globally to any modern commercial refrigerator or freezer, and few offered energy savings significant enough to meet efficiency thresholds for Energy Star ratings sought by original equipment manufacturers (OEMs).
“As their customers search for ways to reduce energy consumption in the face of rising energy costs, OEMs are under increasing pressure to provide energy-efficient solutions, including equipment that is Energy Star rated,” said Ebbe Hassl, product manager – commercial refrigeration, at Danfoss, Baltimore, Md. “There is an obvious trend for more electronic controls. At the same time, many of these customers operate facilities around the world, so finding a universal controller is a priority for them.”
To address the needs of OEMs for a cost-effective, energy-efficient electronic controller that can be applied globally, Danfoss, manufacturers of electronic and mechanical components and control systems for refrigeration and air conditioning, heating and motion controls, developed the first in a series of globally approved, energy-efficient electronic refrigeration controllers, called the ERC 102.
Designed to operate between 50 and 300 V at 50 to 60 Hz, the 0.5 W controller is an energy saver. The mini-computer uses four inputs and four outputs, powerful algorithms and input from multiple sensors to deliver energy-saving compressor, defrost, fan and lighting control in a small, lightweight box.
When fitted on a standard one-door refrigerator with a mechanical thermostat, a fan and a 0.5 HP compressor, the controller can reduce the refrigerator’s energy consumption by up to 52%. Extending the calculation to the seven-year life expectancy of such a merchandiser, savings of 4.5 kWh per day will result in a total energy reduction of approximately 11,500 kWh throughout the refrigerator’s lifetime, according to the company.
In addition, the controller’s electronics consume 70% less power than standard electronics, said Hassl. For example, the unit’s energy-saving design allows the use of a light level sensor to control the economy mode, which takes the cabinet into night set-back by increasing the control set point.
“As a result, OEMs are better positioned to secure an Energy Star rating for their equipment,” said Hassl. “At the same time, end-users reap the benefits of an Energy Star product, including reduced energy consumption and lower utility bills.”
Because the control features a globally compatible, switch-mode power supply, the ERC can be connected from 100 up to 240 VAC powers, which allows one model to be used globally despite differences in voltage supply from country to country. The controller is tested and approved according to UL, NSF, IEC/EN, CQC and GOST standards, including use with hydrocarbon (HC) refrigerants.
“This means that the same controller can operate in the freezing temperatures of a sub-arctic winter or the sweltering heat of the tropics,” Hassl said. “IP65 protection from the front and IP31 from the rear provides resistance to dust, water and condensation. The unit also features patented silicone coating used in the marine sector to protect the power board from moisture and humidity, so no extra enclosure is necessary.”
The ERC 102 can be applied globally to control a variety of functions in glass door merchandisers. Photo: Danfoss
The global compatibility of the unit, along with its ability to function in a variety of operating conditions and control a variety of functions in a single box, can help reduce inventory requirements for OEMs. Fully configurable, the ERC’s control parameters can be set by OEMs and end-users to suit individual operating needs. The product features more than 200 individually programmable parameters.
To avoid accidentally resetting important parameters, the ERC features a three-level password protection function, which gives OEMs and end-users different access levels. “This feature allows the customer to select which parameters users will see and have access to-up to three levels, e.g. end user, service technician and OEM level-ensuring that unauthorized people cannot tamper with control settings,” Hassl explained.
The ERC can be reconfigured to meet new or refurbished refrigerator or freezer control parameters. A computer with Danfoss “KoolProg” software connected to the ERC or a USB-based memory tool allows the OEM or end-user to configure and make parameter changes quickly and effectively.
According to Hassl, installation of the control is just as easy. “It only takes five seconds to mount the ERC on the front or back of the refrigerator. Drawing on the Japanese poka-yoke error-proof assembly principle, color-coded wires, sensors and connectors can be attached in less than 20 seconds. As a fail-safe to ensure the temperature sensors are attached properly, an internal test sequence can be performed to make sure the controller is ready for installation,” he said.
The unit can be branded and company logos can be applied to the front cover. The four push-buttons are also customizable. “And customers can select from among five colors in the LED display to best suit their application,” said Hassl. “Blue displays, for example, have proven to increase sale of cold beverages.” Danfoss expects to make the ERC 102 available for broad distribution in 2011.
For more information, visit: www.danfoss.com.