How to Test the Voltage on a Three-Phase Generator
- 1). Turn on the generator and bring it up to full operating speed and temperature.
- 2). Connect the wire leads to the multimeter. The black negative wire goes into the negative jack (labeled as "GND" or "COM" on some meters), and the red lead goes into the positive jack ("+V").
- 3). Turn on the meter and set the dial to measure VAC (volts AC). Set the dial to measure the voltage output of the generator, or higher. If the generator puts out 120 volts, set the dial to measure that voltage. If there is no 120 setting, set the dial to the next higher number.
- 4). Insert the thin metal probe on the negative black wire into the left, or negative, outlet receptacle on the generator. Insert the probe of the positive red wire in the right, or positive, outlet receptacle on the generator. Observe the meter display. If the generator is 120 volts, then that voltage should be displayed on the readout.
