HFCL Limited Electrical Maintenance Engineer Interview Questions and Answers

Proximity sensors are devices that detect the presence or absence of an object within a certain range.

• Proximity sensors use various technologies such as capacitive, inductive, ultrasonic, and optical to detect objects.

• Capacitive proximity sensors detect objects by measuring changes in capacitance when an object enters the sensor's electric field.

• Inductive proximity sensors use electromagnetic fields to detect metallic ...read more

Connect one relay to each push button and motor, and connect the relays in parallel to the SMPS for forward and reverse operation.

• Connect one relay to each push button and motor

• Connect the relays in parallel to the SMPS

• Use the push buttons to control the relays and thus the motor direction

There are two main types of motors: AC motors and DC motors.

• AC motors: synchronous and asynchronous

• DC motors: brushed and brushless

• Other types: stepper, servo, linear, etc.

• Motors can also be classified by their power source, size, and application

There are several companies that produce PLCs. I have experience with Siemens and Allen Bradley PLCs.

• Siemens and Allen Bradley are two of the most popular PLC manufacturers

• I have experience running programs on both Siemens and Allen Bradley PLCs

• Siemens TIA Portal and Allen Bradley Studio 5000 are both user-friendly software for programming PLCs

Power factor is a measure of how effectively electrical power is being used. It can be improved by using power factor correction techniques.

• Power factor is the ratio of real power to apparent power in an electrical system.

• It indicates the efficiency of electrical power usage.

• A power factor of 1 indicates all the power is being used effectively, while a power factor less than 1 indicates inefficiency.

• Power factor can be...read more

Yes, I am familiar with Digital Multimeter and can demonstrate its usage for different components.

• For HV diode, set the multimeter to resistance mode and connect the probes to the diode terminals. The multimeter should show a low resistance value in one direction and high resistance in the other direction.

• For HV capacitor, set the multimeter to capacitance mode and connect the probes to the capacitor terminals. The mul...read more

Servo motors are used for high precision control while stepper motors are used for low speed and high torque applications.

• Servo motors have a closed-loop system while stepper motors have an open-loop system.

• Servo motors have higher accuracy and precision than stepper motors.

• Stepper motors have a higher torque output than servo motors.

• Servo motors are more expensive than stepper motors.

• Examples of servo motors include A...read more