Norlake 155697

DEFROST HEATER GLASS DOOR MER

The defrost mechanism in a refrigerator heats the cooling element (evaporator coil) for a short period of time and melts the frost that has formed on it. The resulting water drains through a duct at the back of the unit. Defrosting is controlled by an electric or electronic timer: For every 6, 8, 10, 12 or 24 hours of compressor operation it turns on a defrost heater for 15 minutes to half an hour.

A defrost thermostat opens the heater circuit when the evaporator temperature rises above a preset temperature, 40°F (5°C) or more, thereby preventing excessive heating of the freezer compartment. The defrost timer is such that either the compressor or the defrost heater is on, but not both at the same time.

Doors are common in restaurant equipment design from refrigerators and freezers, to ovens to ice machines. A door is a hinged or otherwise movable panel that allows access to an enclosure, cabinet, bin, or other cavity or container.  A door assembly comprises the components that work in tandem to allow the door to function properly such as the door set, strike, catch and lock set. Doors may be hinged and swing open and closed, or they may slide within a frame. Very frequently, restaurant equipment doors feature tempered glass windows which allow for visual inspection or merchandising of food and beverage products.

A heating element converts electrical energy into heat through the process of Joule heating. Electric current through the element encounters resistance, resulting in heating of the element. This process is independent of the direction of current.