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Power equations for single phased electrical systems.
Single phase power equations:
Wapplied = U I PF / 1000 (1)
Wapplied = real power (kilowatts, kW)
U = voltage (volts, V)
I = current (amps, A)
PF = power factor - 0.7 - 1
W = U I / 1000 (2)
- Brake horsepower is the actual power delivered to or by a shaft.
WBHP = U I PF μ / 746 (3)
WBHP = brake horsepower (hp)
μ = device efficiency
Example - Horsepower vs. Current and Voltage
An AC motor consumes 8 amps of current. The voltage supplied is 12 V, the efficiency of the system is 96% (0.96) and the power factor is 1. The horsepower can then be calculated as
WBHP = (12 V) (8 A) (1) (0.97) / 746
= 0.125 HP
≈ 1/8 HP
- Electrical units, amps and electrical wiring, wire gauge and AWG, electrical formulas and motors.
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- Characteristics of all-aluminum conductors (AAC).
- Calculate amps, hp and kVA for electrical motors.
- Calculate electric motor efficiency.
- Commonly used electrical formulas like Ohms Law and more.
- Calculate electric motors shaft power.
- EV Charging - AC vs. DC, single phase vs. three phase and power vs. voltage and amps.
- Power is the rate at which work is done or energy converted.
- Color codes used in power wiring.
- Convert between single phase (120, 240 and 480 Voltage) and three phase (240 and 480 Voltage).
- Full load amps, wire and conduit sizes for three phase electrical motors.
- Inductive loads and power factors with electrical three-phase motors.
- Electrical 3-phase equations.
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