Elevators, Escalators & Vertical Transport Equipment worked example

Elevator Motor Load Margin with available motor and drive capacity of 21 kW-equivalent: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop available motor and drive capacity to 21 kW-equivalent, then walk the calculation through step by step. Calculate elevator drive motor load margin between available motor capacity and required hoisting load.

The inputs for this scenario

  • Available motor and drive capacity: 21 kW-equivalent (the input this scenario stresses; the baseline uses 42)
  • Required hoisting load demand: 35 kW-equivalent (held at the documented default)
  • Reference load demand: 35 kW-equivalent (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Motor capacity headroom = available motor and drive capacity - required hoisting load demand.
  • Elevator motor load margin works out to -40 % at these inputs, and this is the headline figure for the scenario.
  • Motor capacity headroom works out to -14 kW-equivalent at these inputs.
  • Available motor and drive capacity works out to 21 kW-equivalent at these inputs.
  • Required hoisting load demand works out to 35 kW-equivalent at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where available motor and drive capacity sits at 42 kW-equivalent and the headline result is 20 %, this scenario comes in 300% below the baseline at -40 %.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to available motor and drive capacity, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. It is a steady-state ratio of capacity to demand and does not model acceleration torque peaks, duty-cycle heating, or counterweight balance, so a positive margin alone does not guarantee thermal or dynamic adequacy.

Results at a glance

  • Elevator motor load margin: -40 % (headline result)
  • Motor capacity headroom: -14 kW-equivalent
  • Available motor and drive capacity: 21 kW-equivalent
  • Required hoisting load demand: 35 kW-equivalent

Run it with your numbers

  • To rerun this with your own numbers, open the live Elevator Motor Load Margin calculator, set available motor and drive capacity to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.