Refrigeration Control Raised To A New Degree
To combat food-borne illnesses, the Food and Drug Administration (FDA), an agency of the U.S. Public Health Service, issues its Food Code Recommendations. State and municipal health departments — charged by law with regulating the practices of food stores, restaurants, and all kinds of food-handling and food-storage facilities — draw on the Food Code for their own regulations. One of the key features of the latest Food Code is a recommendation that each food establishment have an effective Hazard Analysis and Critical Control Point (HACCP) plan tailored to its own operations. The HACCP plan identifies hazards that might contribute to food-borne illnesses, and establishes critical points in the food-handling process where controls can help ensure the safety of food.
Refrigerated storage is one such critical point. Refrigerated environments that are used in preparation and storage of food products are required to maintain food at or below 41 degrees F. An exception permits a maximum of 45 degrees in existing equipment that cannot reach 41 degrees if the equipment is scheduled to be upgraded to meet the 41 degree requirement within five years from the date the code takes effect. Date-marked food products must be sold within seven days of their preparation date if held at 41 degrees or less, and within four days if stored at 45 degrees. The 45 degree storage temperature is not allowed in all cases.
In order to help ensure food quality and to comply with Food Code requirements, Danfoss and Hill Phoenix collaborated to develop Degree Master™. It is a smart load-management system designed to provide supermarkets and food preparers with food safety protection, improved product quality with less shrinkage, ease of installation, improved case management, and reduced operating and maintenance costs.
The system is comprised of a load center and an on-case digital display. The load center is designed for single-point power distribution and the digital display unit can be programmed to show product temperatures and case status as well as other operating parameters. The product is factory installed. At the construction site, the installing contractor cables it to the power source and connects it to a host controller (if desired).
Instead of just showing discharge air temperatures, the Degree Master is designed to provide information about overall case conditions. It is designed to monitor temperature at multiple points in the case; show the warmest spot in the case; and allow store personnel to check refrigeration, defrost status, case cleaning, and alarm conditions. In addition, the user can monitor electronic valve operations, anti-sweat heaters, and fan status, and check evaporator coils for frost.
With Degree Master technology, lights, fans, and anti-sweat heaters can be turned on or off for designated cases instead of all cases. The design enables users to add features by adding modules. The base unit includes relays for fans, lights, and basic refrigeration solenoids.
Using single-point power distribution reduces electrical and control wiring; and because it is software driven, fewer monitoring and control components are required. The Degree Master was designed with Echelon® and LonTalk® technologies.
Roche is with Hill Phoenix and Tryson is with Danfoss.
Publication date: 08/05/2002