Definition
A descriptive phrase referring to the closed position of the movable contacts inside a circuit breaker, where they are held firmly against the stationary contacts so electrical current can flow through the circuit. When a breaker is set or reset, a spring-loaded mechanism pushes the movable contacts hard against the fixed contacts to maintain a low-resistance path. If an overcurrent occurs, the mechanism releases and the contacts separate, opening the circuit.
Plain English
It describes the moment a circuit breaker is closed and working normally — the two pieces of metal inside it are pressed firmly together so electricity can pass through.
Context Anchor
Seen in aircraft electrical system descriptions, especially when explaining how a circuit breaker carries current before it trips open.
Why Pilots Care
When the contacts are held tightly together, the circuit is live and the equipment downstream is powered. If the contacts open (the breaker pops), that piece of equipment loses power. Knowing what's happening physically inside the breaker helps a pilot understand why a popped breaker should not simply be reset without thought — something caused those contacts to release.
Analogy
It is like a light switch inside the wall: when the contact points touch firmly, power can flow; when they separate, power stops.
Grounding Statement
Picture the circuit breaker as a small controlled break in a wire: closed means the internal metal parts are touching, open means they are separated.
Intuition Check
This does not mean the pilot should push or hold the breaker in with extra force. It describes the breaker’s internal contacts touching firmly when the breaker is closed.
Example Sentence 1
When the breaker is set, the movable arm holds the contacts tightly against the fixed contacts in the circuit breaker housing, allowing current to flow to the fuel pump.
Example Sentence 2
Inspection confirmed the contacts were tightly against fixed contacts in the circuit breaker housing with no signs of arcing.