Schematic Symbols for Manual and Mechanical Switches

This set of vocabulary flashcards covers common electrical schematic symbols for manual/mechanical switches, inductive/resistive loads, ground types, and circuit protection devices based on lecture notes.

SPST

Single Pole Single Throw manual switch.

SPDT

Single Pole Double Throw manual switch.

DPST

Double Pole Single Throw manual switch.

DPDT

Double Pole Double Throw manual switch.

3PST

A 3 pole Disconnect switch.

N.C.P.B.

Normally Closed Push Button switch.

N.O.P.B.

Normally Open Push Button switch.

Selector Switches

Also known as Dial or ROTARY switches.

TEMP Switch

A mechanical temperature switch that can Open on a rise or Close on a rise.

Liquid Level Switch

A mechanical switch also referred to as a float switch.

Mechanical Switches

A category of switches including Temperature, Pressure, Liquid Level (float), and Flow.

Transformer

A type of Inductive Load represented in electrical schematics.

Motor

A type of Inductive Load represented in electrical schematics.

3PST/FUSED

A 3 Pole fused Disconnect switch.

N.O. Contacts

Normally Open relay contacts.

N.C. Contacts

Normally Closed relay contacts.

Electromagnetic Coil

A component used to actuate relays, classified under electrical schematic symbols.

Resistive Loads

A category of schematic symbols including the Heater, Lamp, Resistor, and Variable Resistor.

Capacitor

An electrical component used for storing charge, represented by two parallel lines in schematic symbols.

Earth Ground

A specific type of connection represented in schematics to indicate a path to ground.

Chassis Ground

A grounding connection specifically to the metal frame or chassis of a device.

Fuse

A device used for Over Current Protection that breaks the circuit by melting a wire.

Circuit Breaker

An automatically operated electrical switch designed to protect a circuit from damage caused by excess current.

Overload

An Over Current Protection device specifically marked with a wavy line symbol in schematics.

Crossing Wires (No Connection)

A schematic shorthand where wires cross each other without forming an electrical junction.

Junction (Wires Connected)

A schematic representation showing a dot at the intersection where wires are electrically connected.

Terminal

A specific connection point at the end of wiring or a component lead.