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Example:

Given 120/24 Volt Transformer with 20 Ampere primary OCPD

Find: Ampacity (Ic) Required for secondary conductors.

Solution:

20 <= 24/120 x Ic
Ic>= (120/24) x 20 amperes
Ic >= 100 amperes
Answer:
The secondary conductors shall have
an ampacity greater than or equal to
100 amperes to comply.

Example:

Given a 20 ampere OCPD used on a
controlled light and power circuit.

Find the required Ampacity (Ic) of Class 1 tapped conductors No. 14 and larger.

Solution:

Ic >= 20/3
Ic > 20/3 amperes
Ic >= 6.7 amperes

Answer:
A No. 14 conductor rated at 15 amperes is acceptable.

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