How this is calculated
Inspect the versioned inputs.
| Constant | Value | Scope & source |
|---|---|---|
| wattsPerKW | 1000 W/kW | Exact unit definition or derived time/volume conversion. nist-unit-tables ↗ Verified 2026-11-08 |
Input defaults that are not sourced measurements are illustrative planning assumptions. Exact unit definitions, the 52-week convention and algorithm details are in the shared methodology.
Worked example
An example you can inspect.
CORE 9 at 240 V is 9,000 / 240 = 37.5 A. Its cited manual row specifies a 50 A breaker and 8 AWG; this is a model example for professional confirmation.
Keep arithmetic and installation requirements separate.
The power calculation describes an idealized resistive load at the entered supply voltage. Single-phase current is power divided by voltage; the balanced three-phase expression includes the square root of three. Choosing a supply in this calculator does not establish that the equipment supports it. Before interpreting the result, check the exact heater and control model, rated supply and wiring arrangement. A numerical current result cannot identify the correct branch-circuit protection or conductor for an arbitrary installation.
Read only the matching manual row.
The reference rows preserve the documented power, current, breaker and conductor context for selected CORE supply variants. The 208-volt variants have different rated power from the corresponding 240-volt examples. Do not substitute a 240-volt kilowatt value into a 208-volt product row to make a desired output appear. The user-entered arithmetic and the selected manual row may intentionally describe different things. The interface labels that distinction so a planning comparison is not mistaken for an equipment schedule.
Prepare a concise electrician handoff.
Take the exact product manual, nameplate details, proposed heater location and available service information to the electrician. Ask the professional to establish the applicable supply, circuit protection, conductors, controls, installation conditions and local requirements together. The calculator does not evaluate the building's service capacity, route, ambient conditions, terminations or every installation rule. If any product or supply assumption changes, replace the reference document and recalculate the arithmetic. Keep the output as an informational planning note rather than using it as permission to purchase wire or alter a circuit.
Check the consistency of the starting information.
Power, supply voltage and current should all refer to the same product configuration. A family name can cover several variants, and a manual can describe more than one wiring arrangement. The source register identifies the selected example rather than assuming that every row in a product family is interchangeable. If the label and instructions conflict, stop using that row as a planning reference and ask the manufacturer or installer to resolve the discrepancy. This project excluded a model row whose stated power and current were internally inconsistent.
Keep the output attached to its assumptions.
The theoretical result is only reproducible when its entered kilowatts, volts and phase selection travel with it. Record those three inputs beside the result. Keep the separate manual reference clearly labeled so a reader can tell which number was calculated and which was quoted. A later change in supply or product makes the old arithmetic obsolete. The final installation decision belongs to the professional applying the current product instructions and the requirements of the actual site.
Questions, considered
Questions about this tool
How should I interpret the electrical requirements checker result?
Not a substitute for a licensed electrician or local code. Conductor insulation, ambient temperature, run length, derating, disconnects, controls and supply configuration remain unassessed. Translate power and supply into theoretical heater current, and compare clearly labeled manual examples for an electrician to review.
Which assumptions matter in the electrical requirements checker?
For a resistive single/line-to-line load, I = 1,000 × kW / V. For balanced three-phase, divide by √3 × line voltage at power factor 1. Only the selected CORE US manual supplies the displayed breaker and conductor example; the arithmetic does not size a circuit. Use each model’s reduced rated output at 208 V. Do not apply the 240 V nameplate kW to a different supply.
Primary sources
Follow the source.
- HUUM CORE US installation and operation manual, v9 ↗
Printed pp.4–6: sizing, Tables1–3 and installation; pp.9–11: room and ventilation
CORE9/11 rows are consistent with P/V. CORE6 is excluded: its 240V table pairs6.5kW with25A, which does not match P/V; the208V row also conflicts. Preserve this discrepancy rather than silently correct a manufacturer's table.
Checked 2026-11-08