Wiring a 110 or 220 volts split phase capacitor start AC motor to achieve a dual voltage 110 and 220 volts connection and to be able to run the motor in both forward and reverse direction can be achieved by knowing the order and arrangement of its internal coil winding connection and its associated internal electrical components.
Split phase motors should not be confused with capacitor start motors since they are both identical in nature except for the additional capacitor connected to the start coil of the capacitor motor which makes it distinguishable from the split phase motor.
These type of motors are constructed to have two types of coil winding namely the start coil and the run coil. To determine which terminal is for the start coil and which terminal is for the run coil in case of absence of terminal markings, the easiest way to determine this is by remembering that the start coil would mostly be the coil with the higher ohms reading than the run coil. So it would always be a good practice to take a resistance reading of the coil terminals by using an
Electrical Multimeter to determine which is which.
The start coil winding provides the configuration for the forward or reverse direction of the motor rotation, it is made of thinner wires than the run coil and is wound with more turns than the run coil too, thus the start coil has a higher resistance reading than the run coil. The start coil is used briefly only during the start-up run of the motor and is disconnected from the motor's internal circuit by the centrifugal switch once the motor attains enough rotating inertia as it picks up speed from standstill.
The electrical diagram below shows the different types of wiring connection to achieve both 110 and 220 volts configuration including the achievement of both forward and reverse rotational direction of the motor.
220 Volts Configuration:
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| Fig-1 Wiring Connection of a Split Phase Capacitor Start Motor supplied with 220 Volts in Forward Rotation |
The drawing in Fig-1 above shows a split phase capacitor start motor supplied with a single phase 220 volts on terminal L1 and L2 of the series connected run coils 1 and 2. The start coil winding is configured in the order L1 connected to the start capacitor which is in series with the start coil 1 and the start coil 2 where its end is connected to the center tap terminal between run coil 1 and run coil 2, which provides the forward rotational direction of the motor powered by a 220 volts AC supply source voltage.
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| Fig-2 Wiring Connection of a Split Phase Capacitor Start Motor supplied with 220 Volts in Reverse Rotation |
The drawing in Fig-2 above shows a split phase capacitor start motor supplied with a single phase 220 volts on terminal L1 and L2 of the series connected run coils 1 and 2. The start coil winding is configured in the order L1 connected to the start coil 2 and start coil 1 which is in series with the start capacitor and the centrifugal switch where its end is connected to the center tap terminal between run coil 1 and run coil 2, which provides the reverse rotational direction of the motor powered by a 220 volts AC supply source voltage.
110 Volts Configuration:
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Fig-3 Wiring Connection of a Split Phase Capacitor Start Motor supplied with 110 Volts in Forward Rotation
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The drawing in Fig-3 above shows a split phase capacitor start motor supplied with a single phase 110 volts on terminal L1 and L2 of the parallel connected run coils 1 and 2. The start coil winding is configured in the order L1 connected to the start capacitor which is in series with the start coil 1 and the start coil 2 where its end is connected to L2, which provides the forward rotational direction of the motor powered by a 110 volts AC supply source voltage.
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| Fig-4 Wiring Connection of a Split Phase Capacitor Start Motor supplied with 110 Volts in Reverse Rotation |
The drawing in Fig-4 above shows a split phase capacitor start motor supplied with a single phase 110 volts on terminal L1 and L2 of the parallel connected run coils 1 and 2. The start coil winding is configured in the order L1 connected to the start coil 2 and start coil 1 which is in series with the start capacitor and the centrifugal switch where its end is connected to L2, which provides the reverse rotational direction of the motor powered by a 110 volts AC supply source voltage.
