⚡AC
1. There are 6 terminals of the AC motor with all equal sizes.
2. There are cooling strips in the AC motor.
3. The cooling fan is outside of the AC Motor.
⚡DC
1. DC Compound Motors also has 6 terminals but 4 of them are of the same size and 2 of the terminals are always smaller than the other four.
2. There are no cooling strips in DC Motor.
3. The cooling fan is inside the DC Motors.
- Synchronous motors have 5 terminals of which 3 of them are used to connect three phases (AC) and 2 of them are for rotor excitation and provided with DC supply.
- If a motor has 4 terminals then it will lie in the category of DC Motors.
- If a motor has 3 terminals then it will be a Y-connected AC Motor and its windings are connected in star internally.
- If a motor has 2 terminals then it will be a single-phase induction motor..