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Switchboard Phase Allocation Calculator

Add prospective single-phase loads to a balanced three-phase base load and show phase spread before circuit allocation.

Inputs

Project inputs and assumptions

Range: 0–100,000 A

Enter the prospective demand assigned to L1 after applying the project's load assumptions.

Range: 0–100,000 A

Enter the prospective demand assigned to L2 after applying the project's load assumptions.

Range: 0–100,000 A

Enter the prospective demand assigned to L3 after applying the project's load assumptions.

Range: 0–100,000 A

Enter the line current of loads assumed balanced across all three phases; this adds equally to each phase.

Result

Average phase current (A)
71.67
Prospective L1 total (A)
75.00
Prospective L2 total (A)
68.00
Prospective L3 total (A)
72.00
Phase spread (A)
7.00
Result basis
The phase totals and spread show the proposed allocation before circuit-by-circuit adjustments. Use the spread with the project demand, neutral, fault-level and applicable Australian switchboard checks; no universal balance limit is assumed.

Formula

Calculation logic

Formula definitions and substituted values.

Before relying on the result

  • Review a prospective phase allocation before installation
  • See how a balanced three-phase load affects single-phase phase spread
  • Use the result as an allocation screen; verify actual circuit phases, neutral loading, fault levels and applicable installation requirements separately.

Related calculators

Use the result as an allocation screen; verify actual circuit phases, neutral loading, fault levels and applicable installation requirements separately.