664/663 Quiz UKPN

A cable's current carrying capacity is...

• directly proportional to the number of cores

• inversely proportional to the cross-sectional area of each core

• inversely proportional to the number of cores

• directly proportional to the cross-sectional area of each core

The number of strands in a standard 132 kV overhead line conductor is...

• 7

• 65

• 37

• 59

The purpose of preventative maintenance is to...

• make sure all faults will occur at a certain time

• allow new transformers to be purchased on time

• maximise uptime and continuity of the service.

• ensure there will never be any faults on the system

Substation interlock systems are used to ensure...

• one master key will open the substation

• the transformer can operate under wireless control

• all transformers on the ring are connected together.

• the correct sequence of operations are followed

In a substation, 'Neutral earthing resistors' are used in order to?

• limit current to earth

• balance phase currents

• So that it enables the transformer core to be earthed

• protect the consumer from dangerous voltage

Compared with cables laid directly in the ground, cables drawn into ducts have...

• increase failure rate

• the same rating

• a lower rating

• a higher rating

On-load tap-changing incorporates some form of impedance to prevent....

• short-circuiting the tapping sections

• open-circuiting the tapping sections

• excessive voltage rise during operation

• excessive voltage drop during operation.

The information, ‘3 x 1c 300Al XLPE 11 kV’ is recorded on a cable plan. The correct interpretation of this information is.......

• 3 times 1 centimetre, 300 ampere line, unsheathed 1100 V cable

• 3 single cores, 300 mm² aluminium, sheathed 11000 V cable.

• 3 core plus 1 core 300 ampere line, lead sheathed 11000 V cable

• 3 core 300 mm²

Excessive corona on a 275 kV overhead transmission line could be an indication of....

• interference caused by a kite string

• exceptionally dry weather conditions

• a bird's nest in the top hamper of the tower.

• broken strands or spacers

What effect does ice have on an overhead conductor?

• Increases the effect of wind pressure.

• no effect.

• Reduces the tension in the conductor.

• Decreases the effect of wind pressure.