I

INDEPENDENT/DEPENDENT
see Dependent/Independent

INDEXING PIN
A small bar that projects from the front of a rotary switch, which engages in the mounting surface. It ensures that the switch body will not rotate when the actuator is turned. See picture below:

Cole Hersee makes switches with or without indexing pins. Note that if you need a faceplate for a switch with an indexing pin, you need to select the one with a corresponding hole.

INRUSH CURRENT
The initial surge current that occurs during closing of contacts, which is characteristic of capacitative and some resistive loads. This can cause severe degradation of the contacts, even resulting in welding where the contacts fuse together. Inrush can be 10 to 16 times steady state characteristics.
Cole Hersee switches are designed to be able to withstand high levels of inrush, but is important to specify the appropriate switch for any expected inrush situation.

INVERTER
A device used to change DC into AC power. Becoming increasingly important in truck cabs, as more devices (such as computers and microwave ovens) are being used onboard. The same applies to the marine environment.
Gensets (generators) also provide 120V AC, but they do this by generating electricity from a dedicated gas engine.They are more suitable for large continuous loads. Inverters are quiet, and are better suited to a variable, relatively small electrical demand.

ISOLATION TRANSFORMER
A multiple winding transformer with primary and secondary windings physically separated and designed to permit magnetic coupling between isolated circuits.