SCHEMATIC SYMBOLS AND DEFINITIONS BASIC HYDRAULIC COMPONENT SYMBOLS Pump or Motor Variability Spring (Adjustable) Fluid Conditioner Spring Pressure Compensation ACCUMULATORS Control Valves Line Restriction (Variable) Spring Loaded Gas Charged Restriction Line Restriction (Fixed) PILOT CONTROL Line Restriction Variable and Pressure Compensated MAIN AUX. RELEASED PRESSURE 2-Section Pump External Return Internal Return Pump: Variable and Pressure Compensated REMOTE SUPPLY PRESSURE Attachment Simplified Hydraulic Pneumatic Energy Triangles HYDRAULIC SYMBOLS - ELECTRICAL Transducer (Fluid) BASIC ELECTRICAL COMPONENT SYMBOLS HARNESS AND WIRE SYMBOLS Fuse:
A component in an electrical circuit that will open the circuit if too much current flows through it. Wire, Cable, or Harness Assembly Identification: Includes Harness Identification Letters and Harness Connector Serialization Codes (see sample). Switch (Normally Open): A switch that will close at a specified point (temp, press, etc.). The circle indicates that the component has screw terminals and a wire can be disconnected from it. AG-C4 111-7898 L-C12 3E-5179 Switch (Normally Closed): A switch that will open at a specified point (temp, press, etc.). No circle indicates that the wire cannot be disconnected from the component. Part Number: for Connector Plug 1 Ground (Wired):
This indicates that the component is connected to a grounded wire. The grounded wire is fastened to the machine. 2 Plug Receptacle Ground (Case): This indicates that the component does not have a wire connected to ground. It is grounded by being fastened to the machine. Harness Identification Letter(s): (A, B, C, AA, AB, AC, ...) Pin or Socket Number Reed Switch: A switch whose contacts are controlled by a magnet. A magnet closes the contacts of a normally open reed switch; it opens the contacts of a normally closed reed switch. Harness Connector Serialization Code: The "C" stands for "Connector" and the number indicates which connector in the harness (C1, C2, C3, ...) Sender:
A component that is used with a temperature or pressure gauge. The sender measures the temperature or pressure. Its resistance changes to give an indication to the gauge of the temperature or pressure. L-C12 3E-5179 T 5A Relay (Magnetic Switch): A relay is an electrical component that is activated by electricity. It has a coil that makes an electromagnet when current flows through it. The electromagnet can open or close the switch part of the relay. Fuse (5 Amps) 9X-1123 Component Part Number Harness identification code: This example indicates wire group 325, wire 135 in harness "AG". 325-AG135 PK-14 Solenoid: A solenoid is an electrical component that is activated by electricity.
It has a coil that makes an electromagnet when current flows through it. The electromagnet can open or close a valve or move a piece of metal that can do work. Wire Color Wire Gauge 1 2 Deutsch connector: Typical representation of a Deutsch connector. The plug contains all sockets and the receptacle contains all pins. Magnetic Latch Solenoid: An electrical component that is activated by electricity and held latched by a permanent magnet. It has two coils (latch and unlatch) that make electromagnet when current flows through them. It also has an internal switch that places the latch coil circuit open at the time the coil latches. 1 Sure-Seal connector:
Typical representation of a Sure-Seal connector. The plug and receptacle contain both pins and sockets.
2 VALVES ENVELOPES One Positi on Two Position Three Position PORTS Two-way Three-Way Four-Way CONTROL A B A B P T tion Shifted Position Infinite Position P T ormal Posi CHECK Basic Symbol Spring Loaded Shuttle Pilot Controlled INTERNAL PASSAGEWAYS FLOW IN ONE FLO DIRECTION EIT Infinite Positioning W ALLOWED IN HER DIRECTION Two Position PARALLEL CROSS FLOW FLOW Three Position PUMPS FIXED DISPLACEMENT Unidirectional Bidirectional VARIABLE DISPLACEMENT NON- COMPENSATED Unidirectional Bidirectional CYLINDERS Single Acting Double Acting MOTORS FIXED DISPLACEMENT Unidirectional Bidirectional VARIABLE DISPLACEMENT NON- COMPENSATED Unidirectional Bidirectional ROTATING SHAFTS Unidirectional Bidirectional Complete Internal Supply Pressur COMBINATION CONTROLS olenoid Solenoid or Manual Solenoid and Pilot Solenoid and Pilot or Manual Servo Thermal Detent LINES Crossing Joining MEASUREMENT Pressure Temperature Flow MANUAL CONTROL Push-pull Lever Manual Shutoff General Manual Push Button Pedal Spring FLUID STORAGE RESERVOIRS Vented Pressurized Return Above Fluid Level Return Below Fluid Level ELECTRICAL SYMBOLS Pressure Switch T Temperature Switch Level Switch Flow Switch Circuit Breaker er Transducer (Gas / Air) G Generator M Electric Motor Pressure Switch Pressure Switch (Adjustable) Electrical Wire Temperature Switch