Dubai Electricity & Water Authority (DEWA) Hvac Technician Interview Questions and Answers

UPS is used to provide backup power in case of electrical outages or fluctuations.

• Provides continuous power supply during outages

• Protects sensitive electronic equipment from damage due to power surges or fluctuations

• Allows for safe shutdown of devices to prevent data loss

• Commonly used in data centers, hospitals, and critical infrastructure

• Types include offline, line-interactive, and online UPS

A substation is a facility used to transform voltage levels and distribute electricity to consumers.

• Substations receive high voltage electricity from power plants or transmission lines

• They transform the voltage to a lower level for distribution to homes and businesses

• Substations may also include equipment for switching, controlling, and protecting the power flow

• Examples of substations include step-down substations, dis

A relay is an electrically operated switch that uses an electromagnet to mechanically control the switching of a circuit.

• Relays are used to control high power circuits with low power signals.

• They consist of a coil, armature, and contacts.

• Common types include electromagnetic relays, solid-state relays, and reed relays.

• Examples of relay applications include automotive starter solenoids and industrial control systems.