The basic quantities.
WHY THEY MATTER
Every specification you read uses them, and misreading them produces wrong purchases.
WHAT VOLTAGE IS
The electrical pressure, measured in volts.
WHAT CURRENT IS
The rate of flow, measured in amps.
WHAT POWER IS
The rate of energy use, measured in watts.
HOW THEY RELATE
Watts equal volts multiplied by amps, for simple loads.
WHAT ENERGY IS
Power used over time, measured in kilowatt-hours.
WHY THE DISTINCTION BETWEEN POWER AND ENERGY MATTERS
Power determines what a system can run at once; energy determines how long.
WHAT THAT MEANS PRACTICALLY
Inverter rating is power. Battery capacity is energy.
WHAT SINGLE PHASE MEANS
The common supply to most small premises.
WHAT THREE PHASE MEANS
A supply with three live conductors, used for larger loads and certain machinery.
WHEN YOU NEED IT
Larger motors, industrial equipment, substantial total load.
WHAT TO CHECK
Whether your equipment requires it before committing to premises.
WHAT FREQUENCY IS
The rate of alternation, stated in hertz.
WHY IT MATTERS
Equipment expects a particular frequency, and generators must hold it.
WHAT POWER FACTOR IS
A measure of how effectively current is converted into useful work.
WHY IT MATTERS FOR GENERATORS
Generator ratings are given at an assumed power factor, and motor loads affect it.
WHAT TO DO
Ask a supplier to size against your actual load, not a nominal figure.
