General Switch Information

Oil pressure switches are activated by hydraulic pressure from the control valve assembly. Depending on design, a switch may function as the ground for an electrical circuit or as a simple connecting switch. All switches are designed to be either normally open (N.O.) or normally closed (N.C.).

N.O. - Means the switch will not allow electric current to flow until the switch is activated by hydraulic pressure.

N.C. - Means the switch will allow electric current to flow until the switch is activated by hydraulic pressure.

FIGURE 2 - TERMINAL SWITCHES:

Also, the switches may be designed with either one or two terminals (see Figure 2). Single terminal switches are used to provide an electrical ground while two terminal switches act as connecting switches.