Capstone - Max Demand

Question 1

AS/NZS 3000 clause 2.2.2 states which four acceptable methods that are acceptable to determine max demand?

Answer 1

1 - Calculation
2 - Assessment
3 - Measurement
4 - Limitation

Question 2

Which appendix of the AS/NZS 3000 will assist with calculating max demand?

Answer 2

Appendix C

Question 3

Which table is used for calculating single and domestic max demand?

Answer 3

Table C1

Question 4

Which table is used for calculating non-domestic installations?

Answer 4

Table C2

Question 5

Which table is used for calculating final sub-circuits?

Answer 5

Table C9

Question 6

What steps should you take when calculating max demand?

Answer 6

1 - Divide into load groups
2 - Distribute across phases
3 - Perform calculations per phase
4 - Total each phase
5 - Check balance

Question 7

The relationship between operating characteristics of a protective device and a conductor against overload is known as what?

Answer 7

Coordination

Question 8

IB ≤ IN ≤ IZ refers to which type of protective device?

Answer 8

Circuit breaker

Question 9

IB ≤ IN ≤ 0.9 x IZ refers to which type of protective device?

Answer 9

HRC fuse

Question 10

The 0.9 derating factor when using an HRC fuse applies to the CCC of the cable, True or False?

Answer 10

False

Question 11

Which standard is used to calculate current carrying capacity for cable selection?

Answer 11

AS/NZS 3008

Question 12

Which version of the AS/NZS 3008 is used in Australia?

Answer 12

1.1

Question 13

What is the default Ambient Air and Soil temperatures used in Australia?

Answer 13

Air - 40C, Soil - 25C

Question 14

What is the definition of current carrying capacity?

Answer 14

Maximum continuous current that a cable may carry without exceeding it’s maximum permissible temperature

Question 15

What characteristic produces heat in a conductor when it is carrying current?

Answer 15

Resistance

Question 16

Which de-rating tables are used for grouping of cables?

Answer 16

T22-26

Question 17

Which de-rating table is used for ambient temperature?

Answer 17

T27

Question 18

Which de-rating table is used for depth of cables?

Answer 18

T28

Question 19

Which de-rating table is used for resistivity of soil?

Answer 19

T29

Question 20

Current carrying capacity must be (greater than, less than) the maximum demand of the circuit.

Answer 20

Greater than

Question 21

Tables 3.1-3.4 are used to determine what information?

Answer 21

Installation method

Question 22

Tables 16 & 17 are used in relation to which type of cable?

Answer 22

Flexible cord that is not fixed wiring

Question 23

Tables 18 & 19 are used in relation to which type of cable?

Answer 23

MIMS

Question 24

Tables 20 & 21 are used in relation to which type of cable?

Answer 24

Aerial

Question 25

Tables 4-15 are used in relation to which type of cable?

Answer 25

Thermoplastic / XLPE

Question 26

What is the standard depth of burial for cable?

Answer 26

500mm

Question 27

When multiple de-rating factors apply to determine cable current carrying capacity, you may use only the one which has the highest de-rating to satisfy the standard - True or False?

Answer 27

False - all de-rating factors apply by compounding