Use compatible equipment
Only use a meter whose voltage, current, plug type, and load category are suitable for the appliance. Never place ordinary plug meters on hard-wired equipment, unsuitable high-power loads, or circuits that require professional access.
Measure energy, not one instant
Instantaneous watts are useful for stable devices. Cycling appliances need cumulative kWh across a representative period. Record the start and end time, normal settings, relevant weather or occupancy, and whether the appliance completed its ordinary operating cycle.
Choose a representative window
A seven-day reading is stronger for refrigerators, air conditioners, dehumidifiers, and other weather- or behaviour-sensitive loads. One complete cycle may be adequate for a washer or dryer, but several cycles reveal programme and load variation.
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How this page was prepared
PowerCost Lab publishes this page to help readers make a specific electricity-cost decision. Worked figures are recalculated from the inputs shown, assumptions remain visible, and market facts are separated from user-entered estimates.
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