FAIL-SAFE ELECTRIC DEFROST
BACKGROUND:
As anyone who has been around electric defrost evaporators knows, electric heating elements can “walk” or “creep” out of coil tubes over time. The re-freezing of liquid water onto the surface of the heating element at the end of the defrost cycle generates extremely powerful forces acting to slowly move the heating element along the length of the vacant space in the heat exchanger. If the heating elements are allowed to creep or walk out of the heat exchanger, damage to electrical wiring and to the element itself will result.