Electrical Relay Diagram and P&ID Symbols From Industrial Text and Video Co. The Leader in Electrical, Motor Control and PLCs Video Training Programs (www.industrialtext.com
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Electrical Relay Diagram Symbols
E LECTRICAL R ELAY D IAGRAM S YMBOLS
SWITCHES Circuit Interrupter
Disconnect
DISC
C1
PRS
LS
CB
Limit (cont.) Maintained Proximity Switch Position Closed Open LS
Liquid Level
PRS
FS
Flow (Air, Water)
Foot
FLS
FTS
Held Closed
Held Open
LS
LS
Normally Closed
FS
PS
PS
Toggle
Cable Operated (Emerg.) Switch
F
TGS
FTS
NP NP
Vacuum & Pressure
Normally Normally Normally Open Closed Open
Normally Normally Normally Normally Open Closed Open Closed FLS
Limit Normally Normally Neutral Position Open Closed LS LS Actuated LS
Circuit Breaker
Temperature Normally Normally Open Closed TS
Plugging PLS
TS
Nonplug
F PLS
F PLS
COS
PB R
2-Position
3-Position
SS F
1
PLS
2
1
SS 2
R
Rotary Selector Nonbridging Bridging Contacts Contacts
Selector
Plugging w/Lockout Coil
RSS
3
RSS
OR
OR
RSS
RSS
1 LO
Thermocouple Switch TCS OFF
–
+
1
–
+
2
–
+
Single Circuit Normally Open
Push Buttons Double Circuit Mushroom PB Head
PB
PB
Total Contacts To Suit Needs Connections, Etc. Maintained Conductors Contact Not Connected Connected PB
Normally Closed PB
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Electrical Relay Diagram Symbols
Contacts Connections, Etc. (cont.) Chassis Plug Time Delay After Coil Relay, Etc. Thermal Ground Or Frame and Normally Normally Normally Normally Normally Normally OverNot Necessarily Recp. Open Load Closed Open Closed Open Closed Grounded GRD
CH
PL
TR
TR
TR
TR
CR
M
CR
CON
M
OL
CON
IDL
RECP
Coils Solenoids, Brakes, Etc. Thermal Relays, Timers, 2-Position 3-Position 2-Position Overload General Etc. Hydraulic Pneumatic Lubrication Element CR TR M CON
SOL
SOL
SOL 2-H
SOL
3-P
Control Circuit Transformer H1
OL IOL
2-L
H3
H2
T X2
X1
Coils (cont.) Reactors (cont.) Adjustable Iron Core
Motors Magnetic Amplifier Winding
Air Core
H4
MAX
3-Phase Motor MTR
DC Motor Armature MTR
X A
X
Pilot Lights
Horns, Siren, Etc.
Buzzer
Bell
AH
ABU
ABE
Push to Test PL
PL
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P&ID Symbols
P&ID S YMBOLS INSTRUMENT LINE SYMBOLS Capillary tube Electric signal EM, sonic, radioactive Hydraulic Pneumatic Process
SYMBOLS FOR TRANSDUCERS AND ELEMENTS FE 10
FE 104
Orifice plate
Venturi or nozzle
FI 5
EE 4
Magnetic
Rotameter
FV 101
Control valve
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P&ID Symbols
INSTRUMENT IDENTIFICATION LETTERING
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
First Letter
Second Letter
Analysis Burner, combustion User’s choice User’s choice Voltage Flow rate User's choice Hand (manually initiated) Current (electric) Power Time or time schedule Level User’s choice User’s choice User’s choice Pressure, vacuum Quantity Radiation Speed or frequency Temperature Multivariable Vibration, mechanical analysis Weight, force Unclassified** Event, state, or presence Position, dimension
Alarm User’s choice* Control Sensory (primary element) Glass (sight tube) Indicate Control station Light (pilot) User’s choice Orifice, restriction Point (test connection) Record or print Switch Transmit Multifunction Valve, damper, louver Well Unclassified Relay, compute Driver, actuator, unclassified
* User’s choice may be used to denote a particular meaning, having one meaning as a first letter and another meaning as a second letter. The user must describe the particular meaning(s) in the legend. This letter can be used repetitively in a particular project. ** Unclassified letters may be used only once or to a limited extent. If used, the letter may have one meaning as a first letter and another meaning as a second letter. The user must specify the meaning(s) in the legend. Reference: ANSI/ISA-S5.1-1984, Instrumentation Symbols and Identification, ISBN 0-87664-844-8
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