The document discusses wiring rules and supply authority requirements regarding motor starting restrictions. It states that due to high starting currents of large motors, supply authorities set limits on these currents to reduce strain on the system and disturbances to other customers. It provides specifics on limiting starting currents to 45A for single phase 240V motors, and provides an equation for calculating limits for 415V motors based on the continuous output of the motor. It also discusses AS/NZ 3000 requirements for overload protection on motors exceeding 0.37kW and references sections on overtemperature protection and motors used in special situations like refrigeration rooms and fire pumps.

1. Learning outcome 5
Wiring rules and Supply Authority
Requirements
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2. Motor starting restrictions
Due to the high starting currents
on large motor the supply
authority sets limits on these
currents to reduce strain on the
system and disturbances on
other customers.
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3. Single phase and SWER motors
Percentage of FLC
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4. Starting currents are limited to 45A for
single phase (240V) motors.
And for 415V motors to a value set by the
equation…
53 + 3.3k Amps
k = the continuous output of the motor
Eg; for a 3Ø 7.5kW motor starting current
must not exceed 77.75A
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5. For 480V motors
17.5 k Amps
K must not exceed 7.5kW except by
special permission from the supply
authority
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6. NUE046 L/O5 7.05 jh 6

7. AS/NZ 3000 requirements
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8. AS/NZ 3000 requirements
Refer to Wiring rules 4.3.4
All motors exceeding 0.37 kW shall
have overload protection.
Refer to 4.3.4.2 for
overtemperature protection
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9. Motors in special situations
Refrigeration rooms 7.4.4.5
Fire pumps 7.10.9
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