Heatcraft Worldwide Refrigeration’s Lead Lag Control System combines the functionality of a room thermostat with a staging controller to reduce staging control complexity. According to the company, the design of the system stemmed from its long history of providing redundant and multistage refrigeration equipment into a variety of critical applications. According to a 2014 Dealer Design Awards contractor judge: “Combining two functions is innovative, and I enjoy setting this system up. It’s wiring is simple.”
A combination of these factors led to the Lead Lag Control System winning gold in the Refrigeration and Ice Machines category of the 2014 Dealer Design Awards.
The Lead Lag thermostat control system provides thermostat and auto-rotation functionality for two to four refrigeration systems in order to provide equal system run times. As many as four temperature inputs may be utilized. The control temperature can use a single sensor input or multiple sensors may be configured to control based on average, maximum, or minimum temperature. The standard operation of the control system is to use all the systems it controls to maintain the desired box temperature. This is accomplished by monitoring the rate of change of the box temperature and turning systems on or off based on the rate of change toward the desired temperature. At any given moment, all systems, or no systems, may be running, depending on the current box temperature and load. Algorithms are built in to stage the systems and maintain even run time between the systems. Staging time of the systems and system safeties are also configurable.
Heatcraft representatives explained that the operators benefit from increased energy efficiency, system reliability, and product stability provided by the product. The encased control panels are preset to interface with a specific number of refrigeration systems. Panels are available to provide control to two, three, or four individual compressor systems in a condensing unit.
Several design research methods, including market studies, were involved in the creation of the system. One method used was market studies. Heatcraft noted the results of these studies gave indications of the overall direction of the market segment, but that the majority of its research came from one-on-one interviews with end users and contractors before, during, and after the product de-
“The Heatcraft Lead Lag control system has given the HVACR industry an innovative integrated thermostat and staging control solution to provide improved refrigeration system control and staging,” said Mark Dutton, lead product manager, Heatcraft. “Refrigeration system reliability is increased by equalizing run times on multiple system applications. This eliminates unnecessary compressor starts. Users will realize tighter, more uniform temperature control of the refrigerated space, as well as increased product integrity, by limiting temperature fluctuations; and increased energy efficiency by eliminating multiple compressors from starting simultaneously. Staging control complexity is reduced, saving the technician time and the end user installation and maintenance costs.”
The company intends to continue researching ways to further enhance the features and capabilities of the Lead Lag Control System as technology for electronic control systems continues to evolve. The company said its goal is to create even more flexibility for the user.
“Heatcraft will focus on developing remote monitoring and control capabilities to increase users’ installation and response times,” said Dutton. “Additionally, the Heatcraft research and development team will be researching ways to expand the control system functionality by utilizing feedback from the pre-existing systems currently in cold storage and food service applications.”
Heatcraft Worldwide Refrigeration dominated this category, earning the silver award for its Split System Controller, as well. According to the company, the electronic control replaces mechanical controls required for defrost operation.
Eliminating the use of a mechanical defrost time clock, defrost termination switch, and room thermostat, the Split System Con-
troller performs defrost functionalities directly from the evaporator-mounted control, said Heatcraft.
In addition, the Split System Controller contains the required MODBUS capabilities necessary for remotely monitoring the refrigeration system from any Web-enabled device.
Developed for foodservice applications, the Split System Controller is an evaporator-based electronic system controller, providing a digital display to view room temperature and change parameters. I also provides control of the electric defrost process without wiring back to the condensing unit. Users of the Heatcraft Split System Controller can access factory-set system parameters at the evaporator, which allows for quick set point changes.
Hoshizaki America Inc.’s Stackable Square Cuber Ice Machine model IM-500SAA earned the bronze award in the Refrigeration and Ice Machines category. The stainless steel, air-cooled unit will produce square ice cubes, approximately 1.25-by-1-by-1 inches in size. A single unit on a bin can produce up to 500 pounds of ice per 24 hours. The stacking capability allows for a 100 percent increase in ice production per unit — two units high for 1,000 pounds per 24 hours of ice production and three units high for 1,500 pounds per 24 hours of ice production in the same amount of floor space.
The unit is Energy Star-qualified and, according to the company, saves operation costs by reducing energy usage. It has a jet spray technique that washes away sediment. A closed water plate and circuit maintain sanitation. Applications include restaurants, hospitality facilities, and entertainment venues. The Stackable Square Cuber Ice Machine features an error display to aid in diagnostics, front panel access for quick access to all components, and compartmentalized design that is intended to protect components, preserve unit life, and require less maintenance.
In the future, Hoshizaki plans to expand this line based on research and demand in the U.S. market.
Publication date: 7/21/2014