Voltage = 1

Conductor Material = 12.9

Conductor Size = 0

#Conductors/Phase = 1

Current Draw =

Circuit Length = 1

Voltage Drop =

Voltage Drop =

val1 =

val2 =

Calculates the voltage loss of a circuit over a specified distance and provides information to properly size conductors to prevent an excessive voltage drop.

The 2014 National Electrical Code recommends a maximum voltage drop of 3% for branch circuits and feeders. 2014 NEC 210.19(A)(1), Informational Note #4 also suggests that a total voltage drop of not more than 5% will provide reasonable efficiency of operation of the electrical equipment. This calculator will provide the voltage drop of a circuit based on the length of the circuit, the size and material of the conductors used, the number of conductors per phase, the current draw of the circuit and the system voltage.

NOTE: If the voltage loss of the circuit is greater than 3% of the source voltage, it is strongly recommended that larger conductors be used.

- Voltage: Type of electrical system and the voltage of the circuit.

- Conductor Material:Copper or Aluminum based on the type of conductors to be used for the circuit.

- Conductor Size: Size of the conductors that will be used for the circuit.

- #Conductors/Phase: Number of conductors used for each set of phase conductors. 1 should be selected unless multiple sets of parallel conductors are being used for the circuit.

- Current Draw: Actual current draw of the circuit in amps. If the rating of the circuit breaker is entered into this section, the calculation will result in a greater voltage loss than is actually present.

- Circuit Length: One-way length of the circuit conductors from the origination point of the circuit to the load.

- Voltage Drop: Voltage drop.

- Voltage Drop: Percentage of voltage drop.

Calculate the voltage drop in a 150 foot long, single-phase, 120 volt circuit with a current draw of 18 amps when 12 AWG copper conductors are used for the circuit.

- Voltage: 1∅, 120 volts

- Conductor Material: Copper

- Conductor Size: 12 AWG

- #Conductors/Phase: 1

- Current Draw: 18 amps

- Circuit Length: 150ft

The voltage drops by 10.67 volts and the percentage of drop is 8.89%.

Calculate the voltage dropped in an 85 foot long, three phase, 208 volt circuit with a current draw of 39 amps when 8 AWG copper conductors are used for the circuit.

- Voltage: 3∅, 208 volts

- Conductor Material: Copper

- Conductor Size: 8 AWG

- #Conductors/Phase: 1

- Current Draw: 39 amps

- Circuit Length: 85ft

The voltage drops by 4.49 volts and the percentage of drop is 2.16%.

Voltage

Conductor Material

Conductor Size

#Conductors/Phase

Current Draw

Circuit Length

Voltage Drop

Voltage Drop

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