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ConnectionsMechanical

Wiringterminal

Ground

Notconnected

Notconnected Connected

Miscellaneous

Annunciator

Hornsiren

Half wave

Battery

Full wave

Meter

Fusepower orcontrol

Indicatetype byletter

Metershunt

Thermo-couple

Bell Buzzer

Transformers

DC motors

Capacitors

Wiring

AC motors

Auto

Armature

Current

RES RES RH

VM

AM

AC

DCDC

AC

Resistors

Supplementary contact

Terms

SPST—Single pole single throw

SPDT—Single pole double throw

DPST—Double pole single throw

DPDT—Double pole double throw

N.O.—Normallyopen

N.C.—Normally closed

SPST.N.C.SPST.N.O. SPDT

Heatingelement

Adj. byfixed taps

Rheostat.pot. oradj. tap

Fixed

Adj.

H

Singlebreak

DPST, 2 N.O. DPST, 2 N.C. DPDT

Singlebreak

Doublebreak

Singlebreak

Doublebreak

Singlebreak

Doublebreak

Doublebreak

Singlebreak

Doublebreak

Singlebreak

Doublebreak

PowerControlHomeUndergrnd.Concealed in floor Number ofconductors (4)Exposed

* No. of arrows = no of circuits

Ironcore

Shuntfield

Seriesfield

Comm orcompens.

field

Aircore

Dualvoltage

Singlephase

3 phasesq. cage

2 phase4 wire

Woundrotor

Mechanical interlock

123

ELECTRICAL SYMBOLS