Calcolatore della sezione dei conduttori del motore
// PROGETTA I CONDUTTORI DEI CIRCUITI DERIVATI DEL MOTORE IN BASE A CORRENTE O MCA, MATERIALE DEL CONDUTTORE, DECLASSAMENTO E OBIETTIVO DI CADUTA DI TENSIONE //
Use NEC motor table current or equipment nameplate data as appropriate for the job.
Voltage is used for voltage-drop screening. Single-phase uses a round-trip path, three-phase uses the standard sqrt(3) method.
Distance from source to motor in feet.
Many motor jobs try to stay around 3% on the branch run.
Example: 0.80 for an 80% adjusted ampacity screen.
This is a planning tool for branch-circuit conductors. It does not select overload relays, short-circuit protection, starter settings, or manufacturer-specific exceptions.
8.4 mm2 with adjusted ampacity above the planning target.
4.45 V on the selected conductor.
The recommendation clears the selected ampacity and voltage-drop screens for this motor branch circuit.
The calculator starts with the motor current value you enter.
If you choose Motor FLC, it multiplies current by 125% for a common branch-circuit conductor planning check.
If you choose Equipment MCA, it uses the entered value directly because the listing often already includes the required adjustment.
It then screens each conductor against adjusted ampacity and the maximum voltage-drop target.
Motor overload protection, short-circuit protection, and conductor sizing are related but not identical decisions.
Long motor runs often need upsizing for starting performance even when the ampacity math already passes.
For HVAC, compressors, pumps, and packaged equipment, the nameplate can control more than a generic chart.
Use a lower derating factor when ambient temperature or conductor count reduces usable ampacity.
Check actual terminal ratings before using any 90C column result in final design.
Confirm feeder rules separately if multiple motors share the same raceway or disconnect.
Compare the planned conductor size against manufacturer instructions and local amendments before installation.
For difficult starts, VFDs, or nuisance trips, review the whole motor circuit instead of only the wire size.
Pair this motor branch-circuit result with the tools below before you finalize a pump, air compressor, fan, condenser, or shop motor installation.
Voltage Drop Calculator
Run a broader circuit drop review after you settle the motor conductor size.
Ampacity Calculator
Check temperature, bundling, and conductor material with a more general ampacity workflow.
Conduit Fill Calculator
Verify raceway occupancy once the motor conductors and grounding conductor are selected.
Cable Size Calculator
Compare this motor result with broader feeder and branch-circuit sizing workflows.
Wire Resistance Calculator
Inspect conductor resistance directly if you want to audit the voltage-drop math.
Wire Weight Calculator
Estimate pull weight and reel handling for long motor feeders or large conductors.