Step-by-step example
Scenario: A 3 kW air conditioner runs for 8 hours.
Formula: kWh = kW x hours
- kWh = 3 x 8
- kWh = 24 kWh
Result: 24 kWh energy consumed
Use cases
- Convert between common electrical units during quick checks.
- Cross-check nameplate ratings against measured inputs.
- Compare DC, single-phase, and three-phase scenarios.
- Estimate loads for planning and documentation.
Assumptions & limitations
- Results are estimates and may be rounded; small differences are expected.
- Inputs assume steady-state values; transient and surge effects are not modeled.
- Voltage can vary by supply, load, and location; use measured values when possible.
- Power factor varies by load type; use a realistic value for inductive equipment.
- Wiring rules and safety codes vary by jurisdiction; consult a licensed electrician for installation decisions.
Sources & references
- OSHA Electrical Standards overview - Summarizes electrical safety standards and references NFPA 70/70E.
- OpenStax University Physics - Electrical energy and power - Defines electric power relationships such as P = IV and ties them to circuit variables.
- NIST Glossary - Joule - Defines the joule as a unit of energy and relates it to electrical quantities.
- NIST Glossary - Watt (W) - Defines the watt as a unit of power equal to one joule per second.