Gates Junior Engineer - Maintenance Interview Questions and Answers

Star delta controlling is a method used to reduce the starting current of induction motors.

• Star delta controlling involves initially connecting the motor windings in a star configuration for starting, then switching to a delta configuration for running.

• It is commonly used for large induction motors to reduce the starting current and torque.

• The transition from star to delta configuration is typically controlled by a mot...read more

In star delta connection, typically two contactors are used.

• In star delta connection, one contactor is used for star connection and another contactor is used for delta connection.

• The star contactor is typically rated for the current of one winding, while the delta contactor is rated for the full motor current.

• Using two contactors helps in reducing the starting current and torque in the motor.

• For example, a 3-phase moto...read more

Single line diagram for DOL is a simple representation of Direct-On-Line motor starter circuit.

• DOL starter consists of a contactor, overload relay, and start/stop push buttons.

• The single line diagram shows the connections between these components.

• The power supply is connected to the contactor, which is then connected to the motor.

• The overload relay is connected in series with the motor to protect it from overloading.

• St...read more

There are various types of conveyors, gears and gearboxes, and bearings used in mechanical maintenance. Pulling bearings requires proper technique.

• Types of conveyors include belt, roller, chain, and screw conveyors

• Types of gears include spur, helical, bevel, worm, and planetary gears

• Types of bearings include ball, roller, and sleeve bearings

• To pull a bearing, use a bearing puller tool and apply force evenly to avoid da

Maintenance is the process of ensuring the proper functioning and longevity of equipment, machinery, or infrastructure.

• Maintenance is required to prevent breakdowns and failures, ensuring smooth operations.

• It helps in extending the lifespan of assets and reducing the need for costly replacements.

• Regular maintenance improves safety by identifying and fixing potential hazards.

• It enhances efficiency and productivity by ke...read more