commercial ranges and oven installations in galleys. The current is interrupted ahead of the make-and-break action of the switch contacts. That eliminates the usual pitting and burning of contacts. This switch cannot be repaired; you must replace it.
The basic function of an automatic control is turning current on and off as required to maintain a desired temperature.
The bimetallic blade control switch, as shown in figure 7-12, is operated by the expanding and contracting effect caused by heating two pieces of dissimilar metals that are welded together. Repair of this control is limited to an adjustment in its temperature setting.
Figure 7-12. - Bimetallic blade control switch.
Figure 7-13. - A. Helix control; B. Helix components.
A helix control (fig. 7-13, view A) is used in some domestic, semi-commercial, and commercial installations. It is operated by thermostatic metal that coils and uncoils when heat is applied, regulating a switch to make and break the electric circuit. Repairing this unit consists of replacing miscellaneous parts, such as the dials, switch assembly, helix, helix guard, and so on (fig. 7-13, view B).
A hydraulic control is probably the most frequently used control for automatically regulating the temperature of cooking appliances. In this control, a capillary tube filled with fluid is connected to hydraulicContinue Reading