Construction and Function
- GRID UNIT:   The arc generated between contact is extended, it divides
and cools, and current is intercepted certainly.
- CONTACT:   It consists of a fixed contact and a movable point of contact,
and "ON" and "OFF" of the electricity are carried out.
- SWITCHING MECHANISM:   The mechanism in which each pole opens
and closes contact simultaneously.
- BASE AND COVER:   The synthetic resin cast which has the intensity and
heat resistance which bear the internal pressure of interception, and arc-proof
- TERMINAL:   It is the portion which connects external conductor.
- OVERLOAD TRIP DEVICE:   Overload current and earth leakage current
are detected, and a breaker style is operated. There are Fully Magnetic (Hydr-
aulic Magnetic), Thermal Magnetic, and Electronically controlled in a princi-
ple of operation.
- HANDLE:   It is equipment which performs opening-and-closing operation.
- TRIP BUTTON:   It is the button which trips a breaker from the exterior mec-
hanically. (There are some which are not attached in a product in part.)