Experiment No.: 2
Experiment Name: Starting and Reversing of DC Motor.
Objective:
- To start a DC Shunt Motor.
- To run the motor in forward and reverse direction.
Theory:
DC Motor Rotation:
A simple DC electric motor. When the coil is powered, a magnetic field is generated around the armature. The left side of the armature is pushed away from the left magnet and drawn towards the right, causing rotation. The armature continues to rotate. When the armature becomes horizontally aligned, the commutator reverses the direction of current through the coil, reversing the magnetic field. The process then repeats.
Reversal of Direction of Rotation of a DC Motor:
Investigating the effect on the direction of rotation for the following changes:
Observation:
A. Reverse the shunt field. Start the motor and observe the direction of rotation.
Direction of rotation: Clockwise
B. Reconnected the shunt field as per original circuit, but reverse the armature connections. Start the motor and observe the direction of rotation.
Direction of rotation: Anti-clockwise
C. Reverse both the shunt field and armature connections. Start the motor and observe the direction of rotation.
Direction of rotation: Clockwise
Apparatus Used:
| Sl. No. | Name of the apparatus | Specification | Quantity | Maker’s Name |
| 1. | DC Motor | 3 HP, 220 V DC Shunt, 1500 rpm | 1 | M.E.W. |
| 2. | Starter | 3 Point | 1 | |
| 3. | Connecting Cables | 2.5 sq mm, 1100 V grade | as required | Maru |
Remarks:
CAUTION: TURN THE POWER OFF WHEN MAKING ANY CHANGES. ALWAYS WHEN STARTING THE MOTOR MAKE SURE THE STARTING RESISTOR SWITCHIS TURNED TO THE IN POSITION AND THE FIELD RHEOSTAT IS SET FOR MINIMUM RESISTANCE.
