PIYUSH POLYTEX INDUSTRIES Interview Questions, Process, and Tips

The set current in overload relay is adjusted using a dial or a screw.

• The set current determines the threshold at which the overload relay will trip.

• It is important to set the current correctly to protect the electrical equipment from damage.

• The set current can be adjusted using a dial or a screw on the overload relay.

• The value of the set current is usually specified by the manufacturer or determined based on the elect...read more

A DOL starter circuit diagram is a simple electrical setup used to start and stop motors.

• DOL stands for Direct-On-Line starter

• It consists of a contactor, overload relay, and start/stop push buttons

• The circuit diagram shows the connections between these components

• The main power supply is connected to the contactor, which controls the motor's power supply

• The overload relay protects the motor from overheating

• The start/sto...read more

A VFD has basic parameters like input voltage, output voltage, frequency, current, power, and speed control.

• Input voltage: the voltage supplied to the VFD

• Output voltage: the voltage produced by the VFD

• Frequency: the frequency of the output voltage

• Current: the current supplied to the motor

• Power: the power supplied to the motor

• Speed control: the ability to control the speed of the motor

The formula for finding current in single phase is I = P / (V * cosθ) and in three phase is I = P / (√3 * V * cosθ)

• In single phase, current (I) can be calculated by dividing the power (P) by the product of voltage (V) and power factor (cosθ)

• In three phase, current (I) can be calculated by dividing the power (P) by the product of square root of 3 (√3), voltage (V), and power factor (cosθ)