Page 417 - Industrial Power Engineering and Applications Handbook

Switchgear and controlgear assemblies 13/391
Table 13.16 List of symbols and abbreviations used

Symbol Abbreviation Description Symbol Abbreviation Description

RYBN 3@ and neutral power supply TH Thermostat
sw Heavy-duty switch
D/O Drawout terminal
F Power fuse Terminal

o/c Thermal overcurrent relay
CF Control fuse
h Indicating light
(colour of lenses, R-red, G-green,
FSU Fuse switch unit
A-amber, W-white)
A Ammeter
MCBlcoupledcircuit breaker
ASS Ammeter selector switch
Isolator
V Voltmeter
C Power contactor
(M - main, D - delta,
S - star)
vss Voltmeter selector switch
C Coil of main contactor
d Coil of auxiliary contactor

T Coil of timer CT Current transformer

Normally open auxiliary contact Voltage or control transformer

Normally closed auxiliary contact Tr Power Transformer
R Resistance
OCR Overcurrent relay
L Reactance
TDC
Time delay contacts cs
TDO Current shunt

SH Space heater
s/sw Selector switch
(L/R - locallremote, AIM- auto1
manual)
Surge arrester
Breaker control switch (spring
return to neutral) M Motor
(C - closed, N - neutral, T - trip)
Limit switch with spring charging 0 G Generator
mechanism
Door switch I Cable
Start PB
Pushbutton (colour of knob,
R - red, G - green, Y - yellow) I G Grounding
Stop PB