Single phase motor wiring diagram will help us greatly when dealing with electric motors for most home appliances.
Nowadays, every residence and home appliance uses single phase electricity to operate. It is also true for almost every electric motor we use, such as: water pump motor, hair dryer, and electric fan. This is why a single phase motor diagram is indeed worth learning if we want to do maintenance and repair.
We will learn every single type of single phase motor schematic because single phase motors may have different schematic, connection, and purpose. This is why learning every type we can find is a good thing.
Single Phase Motor Wiring Diagram
Single phase induction motor is an AC motor that operates when supplied with a single phase power. This motor is widely found in home appliances.
Rotor is the dynamic part of an induction motor that rotates inside the motor.
Stator is the static part of an induction motor that produces a rotating magnetic field for the rotor.
Unlike a DC motor, a single phase electricity to the stator will have difficulty on rotating the rotor of an AC motor because there is insufficient rotating magnetic field. An AC motor is well-known for its higher current when starting up the motor.
There will be different single phase motor diagrams along with their modification to make sure they can be operated properly. Even though they are all different, some of them share the same things: a capacitor and a centrifugal switch.
The capacitor will be connected to the auxiliary winding to provide a rotating magnetic field with shifted phase. Some single phase motors will immediately de-energize the capacitor and auxiliary winding when the speed is reaching a point, some of them will still energize it.
You better learn them properly below the connection single phase motor and how to connect single phase motor.
Single Phase Induction Motor Wiring
When studying and observing a single phase motor wiring, we will start with a single phase induction motor wiring. Just as stated above, a single phase motor has difficulty in providing a rotating magnetic field to start rotating the rotor.
This is why the auxiliary winding is deployed to provide an additional magnetic field. Of course adding another winding won’t help anything with rotating the rotor. A capacitor is used to shift the phase so we can get two rotating magnetic fields with different phases.
Below is the single phase motor centrifugal switch diagram.
The centrifugal switch is used to connect the auxiliary winding with the capacitor and the power source. Once the speed reaches a certain value, the switch will disconnect the capacitor and the auxiliary winding from the power source.
From this point onward, only the main winding is energized to make the motor work at steady state.
From this behavior, we can call this a single phase electric motor capacitor switch or capacitor start induction motor because we use the capacitor to switch between start and run.
Permanent Split Phase Capacitor Motor Wiring Diagram
Just as its name implies, this single phase motor diagram will work with a split phase generated by a capacitor. The capacitance from the capacitor and the reactance from the winding will shift the phase to some extent.
Below is the permanent capacitor single phase motor wiring diagram.
This permanent split phase capacitor motor is also known as a single value capacitor motor. This one also doesn’t need a centrifugal switch or any switch to cut off the supply from the auxiliary winding. We will talk about centrifugal switches in other types later.
This motor consists of:
- A cage rotor,
- A stator winding,
- An auxiliary winding, and
- A capacitor for starting up the motor.
Below is how to wire a split phase motor.
Capacitor Start Capacitor Run Motor Wiring Diagram
Now we will learn about the single phase motor 2 capacitor wiring diagram or capacitor start capacitor run motor.
A capacitor start capacitor run motor is also known as a two value capacitor motor. The “two value” comes from the installation of two capacitors for two different purposes: start and run.
In addition to the two capacitors, this motor also uses a centrifugal switch to control the start and run process.
The start capacitor will be connected to the auxiliary winding when the motor is in the starting phase.
After the motor reaches specific speed, the centrifugal switch will disconnect the auxiliary winding from the start capacitor.
This motor has two windings: main winding and auxiliary winding just like other types. The auxiliary winding will help with starting up the motor while the main winding will be supplied at all times.
Because it has two capacitors to provide two phase shifts to each other, we can call this a single phase 2 pole motor wiring diagram.
The figure below is the actual looks of a capacitor start capacitor run motor.
Below is the example of how we wire a capacitor start capacitor run motor.
Shaded Pole Motor
This motor is widely used for low power applications.
This single phase motor is quite different from the previous types, because it doesn’t use capacitor and centrifugal switch to produce desired rotating magnetic fields.
Keep in mind that this motor is relatively small and doesn’t produce high horsepower. It is mostly used for small applications such as an electric fan. This motor is cheap, easy-to-start, rugged, simple, but not efficient. Most of the time, we will throw away this motor once it is broken and buy a new one rather than repair it.
Below is the construction of a shaded pole motor.
Unlike the other single phase motors which use windings as their stator, this motor uses a laminated core as the stator to induce magnetic field. Its rotor will be the same, a squirrel cage rotor.
In addition, a coil is used to produce magnetic flux in the stator lamination.
From its name implies, we need something to represent the “shaded-pole”. Here it uses shading poles from a pair of shorted copper brands, known as shading rings.
The shading rings are not connected electrically in the motor but they produce magnetic fields from the induced current flowing in the coil.
These rings make the rotating magnetic field possible to happen. The rings will delay the generated rotating magnetic flux. This conductor is there to interrupt the complete turn of the pole. The flux is increased but delayed by the induced current in the copper ring.
Below is the actual picture of a shaded pole motor.