10+ Hitachi Interview Questions and Answers

I have worked with various types of motors including AC motors, DC motors, stepper motors, and servo motors.

• AC motors: Used in household appliances and industrial applications.

• DC motors: Commonly found in electric vehicles and robotics.

• Stepper motors: Used in precision positioning systems and 3D printers.

• Servo motors: Found in robotics and automation for precise control.

I am currently handling a portfolio of 15 elevators.

• Currently managing 15 elevators in various buildings

• Responsible for maintenance, repairs, and upgrades

• Regularly communicate with building owners and tenants

• Provide technical support and troubleshooting services

• Track performance metrics and ensure compliance with safety regulations

A transformer is a device that transfers electrical energy between two or more circuits through electromagnetic induction.

• Transformers work on the principle of electromagnetic induction.

• They consist of two or more coils of wire, known as windings, which are wound around a common magnetic core.

• The primary winding is connected to the input voltage source, while the secondary winding is connected to the load.

• When an alternating current flows through the primary winding, it creat...read more

Yes, I am familiar with safety policies.

• I have a strong understanding of safety policies and procedures.

• I am knowledgeable about industry-specific safety regulations.

• I have experience implementing safety measures in previous roles.

• I prioritize the safety of customers and colleagues in my work.

• I am familiar with conducting safety audits and inspections.

A PNP transistor symbol consists of an arrow pointing inward, while an NPN transistor symbol consists of an arrow pointing outward.

• PNP transistor symbol has an arrow pointing inward

• NPN transistor symbol has an arrow pointing outward

A bridge rectifier is an electronic circuit that converts alternating current (AC) to direct current (DC).

• A bridge rectifier consists of four diodes arranged in a bridge configuration.

• It rectifies the AC input voltage by allowing current to flow in only one direction.

• During the positive half-cycle of the AC input, two diodes conduct and during the negative half-cycle, the other two diodes conduct.

• This results in a pulsating DC output that is then filtered to obtain a smoother...read more

A rectifier is an electrical device that converts alternating current (AC) to direct current (DC).

• Rectifiers are commonly used in power supplies and electronic devices.

• They consist of diodes that allow current to flow in only one direction.

• Half-wave and full-wave rectifiers are two common types of rectifiers.

• Rectifiers can be used to convert AC power from the mains to DC power for electronic devices.

• They are also used in battery charging circuits and in converting AC power to...read more

An elevator works by using a system of pulleys, counterweights, and a motor to move the elevator car up and down within a shaft.

• Elevators have a motor that drives a pulley system to move the elevator car.

• Counterweights are used to balance the weight of the elevator car and reduce the load on the motor.

• Safety mechanisms such as brakes and sensors are in place to ensure safe operation.

• Elevators are controlled by buttons inside the car and on each floor to select the desired des...read more

AC and DC are types of electrical current.

• AC stands for alternating current and changes direction periodically.

• DC stands for direct current and flows in one direction only.

• AC is used in household appliances and power grids while DC is used in batteries and electronic devices.

• AC voltage can be easily transformed using a transformer while DC voltage cannot be transformed without a converter.

The operation of a solenoid coil involves the conversion of electrical energy into mechanical motion.

• A solenoid coil consists of a wire wound into a tightly packed helix.

• When an electric current passes through the coil, a magnetic field is generated.

• This magnetic field attracts or repels a movable ferromagnetic core, resulting in mechanical motion.

• The direction of the motion depends on the polarity of the current and the design of the solenoid.

• Solenoid coils are commonly used...read more

An electrical motor is a device that converts electrical energy into mechanical energy.

• Uses electromagnetic fields to generate motion

• Common types include DC motors and AC motors

• Can be classified based on construction (e.g. brushed, brushless) or application (e.g. servo, stepper)

• Examples: induction motor, synchronous motor, brushed DC motor, brushless DC motor

Troubleshooting shooting method involves identifying and resolving issues in a systematic manner.

• Start by gathering information about the issue and its symptoms

• Identify possible causes and narrow down the root cause

• Develop a plan to address the issue step by step

• Test solutions and verify if the issue is resolved

• Document the troubleshooting process for future reference

MCB stands for Miniature Circuit Breaker.

• MCB is an electrical switch that automatically interrupts the flow of current in an electrical circuit during an overload or short circuit.

• It is a type of circuit breaker that is commonly used in residential and commercial buildings to protect electrical circuits from damage.

• MCBs are designed to trip and disconnect the circuit when excessive current flows through it, preventing overheating and potential fire hazards.

• They are compact in...read more