Efs Facilities Services Senior Electrical Technician Interview Questions and Answers

A generator is a device that converts mechanical energy into electrical energy.

• Generators are commonly used to provide backup power during electrical outages.

• They work on the principle of electromagnetic induction.

• Generators can be powered by various sources such as gasoline, diesel, natural gas, or renewable energy.

• They are used in various applications including residential, commercial, and industrial sectors.

• Examples...read more

To manage overloads, ensure proper circuit design, use protective devices, monitor load levels, and implement load shedding.

• Design circuits with appropriate capacity to handle expected loads.

• Install protective devices like circuit breakers and fuses to prevent overloads.

• Regularly monitor load levels using ammeters or power monitoring systems.

• Implement load shedding techniques to prioritize critical loads during high de...read more

UPS stands for Uninterruptible Power Supply.

• UPS is a device that provides emergency power to electrical equipment when the main power source fails.

• It ensures that critical systems remain operational during power outages or fluctuations.

• UPS units typically include a battery, an inverter, and a charger.

• They are commonly used in data centers, hospitals, and other facilities where continuous power supply is crucial.

• UPS can...read more

To connect a battery in a UPS, follow these steps:

• Identify the positive and negative terminals of the battery

• Connect the positive terminal of the battery to the positive terminal of the UPS

• Connect the negative terminal of the battery to the negative terminal of the UPS

• Ensure the connections are secure and tight

• Verify the battery voltage and capacity compatibility with the UPS

• Consider using appropriate cables and connec...read more

The battery voltage during charging time depends on the charging method and the type of battery.

• The battery voltage can vary depending on the charging method used.

• For example, in a constant voltage charging method, the battery voltage remains constant during charging.

• In a constant current charging method, the battery voltage gradually increases as the battery charges.

• The battery voltage also depends on the type of batt...read more

The battery voltage decreases during discharge.

• Battery voltage decreases as the battery discharges.

• The rate of voltage decrease depends on the battery's capacity and load.

• For example, a fully charged 12V battery may drop to 11V after discharging for a certain period.

• Battery voltage can be measured using a voltmeter.

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

• Rectifiers are commonly used in power supplies to convert AC voltage to DC voltage.

• They are made up of diodes, which allow current to flow in only one direction.

• Rectifiers can be half-wave or full-wave, depending on the number of diodes used.

• Examples of rectifiers include bridge rectifiers, vacuum tube rectifiers, and soli...read more

Capacitors in a capacitor bank are connected in parallel to increase the overall capacitance.

• Capacitors in a capacitor bank are connected in parallel.

• The positive terminals of all the capacitors are connected together, and the negative terminals are connected together.

• This parallel connection increases the overall capacitance of the bank.

• For example, if three capacitors with capacitances of 10μF, 20μF, and 30μF are con...read more

In a power failure situation, it is important to have a plan in place to manage the situation effectively.

• Ensure backup power sources are available, such as generators or uninterruptible power supplies (UPS)

• Implement a power outage response plan that includes procedures for safely shutting down equipment and systems

• Regularly test backup power systems to ensure they are in working order

• Have emergency lighting and commun...read more

The appropriate fire extinguisher to use in an electrical fire is a Class C fire extinguisher.

• Class C fire extinguishers are specifically designed to extinguish fires involving electrical equipment.

• They contain non-conductive extinguishing agents, such as carbon dioxide or dry chemical powder, to safely put out the fire without conducting electricity.

• It is important to never use water or foam-based extinguishers on ele...read more

A digital multimeter (DMM) is commonly used for earth testing.

• A digital multimeter (DMM) is a versatile tool that can measure resistance, voltage, and current.

• For earth testing, the DMM is used to measure the resistance between the earth electrode and the grounding system.

• The DMM should be set to the resistance (ohms) mode and connected to the earth electrode and grounding system.

• The measured resistance value helps det...read more

The earth ohm resistance refers to the resistance of the earth or ground in an electrical circuit.

• Earth ohm resistance is a measure of how easily current can flow through the earth.

• It is important to have a low earth ohm resistance to ensure proper grounding and safety in electrical systems.

• The earth ohm resistance can vary depending on factors such as soil composition, moisture content, and temperature.

• Typically, a go...read more