Electrical Power Engineering - Distribution and Transmission

What type of cable is XLPE?

• Plain lead covered earth cable.

• Mineral insulated cable.

• Cross linked polyethylene insulated cable.

• Steel wired armoured cable.

What type of gas is used in a gas filled cable?

• Carbon dioxide.

• Oxygen.

• Helium.

• Nitrogen.

What does not affect the rating of a cable?

• Being drawn into a cable duct.

• Being installed using cable cleats.

• The type of soil in which it is laid.

• A number of cables grouped together.

What is the purpose of screening 3-phase high voltage cables?

• Stops electrolytic action.

• Controls tangential stresses.

• Provides a good earth continuity.

• Gives extra mechanical protection.

What should happen to un-armoured lead sheathed cables laid in the ground?

• Be encased in concrete.

• Always be drawn in ducts.

• Surrounded by sand or similar graded material.

• Backfilled with the excavated soil with no specific precautions taken.

What must happen to cables being pulled into a draw-in system?

• Supported on rollers throughout their length.

• Supported at the duct entrance.

• Pulled in by means of a winch.

• Pulled in by hand.

What is the main advantage of keeping cable records and data?

• Makes fault predictions much quicker.

• Makes sense to untrained individuals.

• Makes excellent use of I.T. equipment.

• Makes system maintenance more efficient.

What do the letters ABSD refer to for an item on a cable plan?

• An aerial bundled steel distributer.

• An air blast system disengage.

• An air break switch disconnector.

• An aerial balanced safety distancer.

What should be reviewed regarding all buried services in the area before any excavation work starts?

• Correct tools and equipment.

• Permission from the owner.

• Programme of work.

• Plans or other suitable information.

What is the reason for bonding underground cables before jointing?

• To ensure all live conductors are separated.

• To ensure the neutral conductor is floating at 25 V.

• To ensure continuity of the earth.

• To ensure spiking can be undertaken.