Pneumatic Control Circuit Wiring - 5 Flashcards
What are Pneumatic systems?
Pneumatic systems use pressurized gas, typically compressed air, as their power source.
What is an example of a pneumatic system?
A Jackhammer.
What five basic components are consisted of in a pneumatic system?
- Power Input Devices
- Control Devices
- Power Output Devices
- Conductors
- Gas
What is the power input device that provides pneumatic power to the system?
A Pump. Also called an Air Compressor.
What does an Air Compressor do?
An Air Compressor draws air from the atmosphere, compresses it, and then pushes it into the supply line.
Name a common control device used in a pneumatic system.
A Valve.
What are Valves used for?
Valves are used to control the direction, pressure, and flow rate of the pressurized air in the system.
List a Power Output Device used in a pneumatic system.
Actuators.
What do actuators do
Actuators convert pneumatic power to mechanical power.
Name two common types of pneumatic actuators.
- Cylinders
* Motors
What type of motion do cylinders provide?
Linear motion.
What type of motion do motors provide?
Rotary motion.
What is a conductor in a pneumatic system?
A conductor is the pipe, tube, or hose that transmits the air between pneumatic components.
What is the main conductor in a pneumatic system called?
The Supply Line.
What is the most common gas used in a pneumatic system?
Air. (Air is a mixture of gases)
Which three industries use pneumatic applications?
- Manufacturing
- Transportation
- Construction
What features of pneumatic systems make them appealing?
- High Speed
- Clean Operation
- Low Cost
What is an important concept in pneumatics?
Pressure.
What is one common way to measure pneumatic pressure?
A Pressure Gauge.
What units of measurement are used in a pressure gauge?
- US Customary Units (PSI)
* SI Metric Units (Pascals)
What is a Pressure Regulator Valve?
Controls pressure flowing downstream from the air supply.
Why is a Pressure Regulator Valve usually needed?
The air pressure needed for pneumatic system applications is often less than the pressure available from the main air supply.
What does a pressure regulator valve consist of? (Six Components)
- Body
- Restricting Element
- Loading Element
- Adjustment Spring
- Adjustment Knob
- Poppet Spring
Symbol for Pressure Regulator.
https://imgur.com/a/vBjNGCl
What is the description of an Actuator?
Actuators are the pneumatic components that convert air power into mechanical power.
What does a Cylinder (Type of Actuator) do?
A Cylinder converts air power into mechanical power in the form of linear motion.
What does a pneumatic cylinder consist of?
A Piston/Rod that can move inside a barrel-shaped body.
Double-Acting Cylinder Schematic Symbol
https://imgur.com/a/bd8nY4I
What is a directional control valve (DCV)?
A DCV controls the direction of air flow.
What do pneumatic DCV’s have that specify them?
- Number of flow paths
* Number of Positions to which the valve can be moved
A common type of DCV is a 5-ported, 4-way, 3-position. What are its applications?
Extend, Retract, and Stop in mid-position.
What components does a 5-ported, 4-way, 3-position DCV consist of?
- Valve Body
- Operator
- Spool
- Springs
- Ports
What type of DCV is designed to directly operate on the valve spool?
A Solenoid-Operated DCV.
What are solenoids composed of?
Frame, Coil, and Armature.
What does a 3-position DCV require?
Two solenoids. One on each end.
What are pneumatic solenoid valves equipped with to allow the valve to be manually shifted?
One or more manual overrides.
What is a schematic?
A Schematic is a circuit drawing that uses standard symbols to represent components.
What is the purpose of a schematic circuit diagram?
It helps the user determine how a circuit operates.
How do you interpret a pneumatic schematic?
Start at the air power supply and follow the lines to the individual components.
What schematic is often shown alongside a control diagram?
Power diagram.
What format is a control diagram shown in?
A Ladder Diagram.
What format is a power diagram shown in?
A Schematic with the addition of electrical wiring connections.
What diagrams are needed for connecting an Electro-pnuematic circuit?
Both a control diagram and power diagram.
The control diagram shows the components that control the what?
The Electro-Pneumatic System.
The power diagram shows the components that perform the what?
The Pneumatic Operation.
What are several important points for proper wiring technique in electro-pneumatic control systems?
- Running Wires through Conduit
- Wire Labeling
- Terminal Blocks
- Terminal Connection Methods
Wires that are outside panel boxes are run through what?
Conduit.
Constantly _____ each wire according to the ladder diagram.
Label.
What do you use when exiting or entering a panel or junction box?
Terminal Blocks.
What are typically connected in an electro-pneumatic system connected to wires that are routed from electrical panels.
Solenoid valves.
The wires from an electrical panel are sometimes routed to a junction box before they are connected to what?
The Solenoid Valve.
What three solenoid wiring connections are there?
- Direct Terminal Connection
- Spliced Connection
- DIN Connection
What do some solenoid valves have that directly connect to the control wires?
Terminals.
What are the steps for Direct Terminal Connection method?
- Strip a portion of insulation from the wire.
- Twist the end of the exposed wire if it is stranded.
- Attach the wire under the terminal screw clamp.
- Tighten the screw to secure the wire
Some solenoid valves are connecting by ________ the control wires to fixed wires coming out of the solenoid.
Splicing.
All wire splice connections must be contained inside a …?
Junction Box.
Wires are spliced to a solenoid valve wires using the following steps:
- Remove junction box cover to expose the two wires.
- Strip a portion of insulation from both wires.
- Twist both wires together for several turns.
- Cut the end of twisted wires to leave about 0.5 inch of exposed wire.
- Attach a wire nut to the exposed wires.
- Wrap electrical tape around the wire nut and wires.
- Replace the junction box cover.
Control wires are connected to the terminal block using the following steps:
- Remove DIN housing from solenoid coil.
- Remove terminal block from DIN housing.
- Connect one wire to the positive terminal.
- Connect the other wire to the negative terminal.
- Place terminal block into the DIN housing.
- Replace DIN housing back onto the solenoid coil.
What is the description of a flow control valve?
Flow control valves restrict fluid flow in one direction and allow free flow in the other direction.
A flow control valve allows you to adjust the _____ of the actuator in one direction when connected to either the inlet or outlet port.
Speed.
You can control the Actuator’s both __________ when connecting flow control valves to both ports.
Directions.
What does a Meter-In circuit do?
A Meter-In Circuit provides precise control and is a common method of controlling speed.
Why is a Meter-In Circuit only used in a couple applications?
It is only used to control cylinder speeds when the load opposes the rod movement.
