Electrical Output Testing Procedure

Updated 2 years ago by Juan Velez

This covers the following Champion Power Equipment models: 2800W-9500W Generators, Brush Type System.

Read instructions carefully and completely before performing service.

  • To reduce the risk of injury, user must read and understand the operator’s manual before using this product.
  • DO NOT make any adjustments to the generator without first stopping the engine and disconnecting the spark plug wire.
  • Burns from hot parts — let the engine cool completely before touching hot parts.
  • Injury from moving parts
  • To reduce the possibility of fire or explosion, be careful when working around gasoline. Keep cigarettes, sparks and flames away from all fuel‐related parts.

I. Flash Test DC Voltage to Brush Assembly

  1. Remove the round yellow end cover to the left of the muffler. At the uppermost position you will see a red wire (+) and a white wire (-) connected to the brush assembly.
  2. Remove the white wire first. With the wire disconnected, start the engine and scratch the wire against the terminal it was originally from. This should produce an electrical arc. This is DC power only and there is no danger of electrical shock.
  3. If a spark does appear, reconnect the white wire to its terminal and there should be power to the outlets and meter. If there is no power, reassemble the unit.
  4. If there is no spark, go ahead and remove the brush holder and examine the carbon brushes for damage, uneven, or excessive wear. (Remove the bolt below the red wire. Remove the brush support plate and lift the brush assembly up and out of its position. The brushes should be between 3/8" and 3/16" and relatively equal in length. Regular use of the generator can cause wearing of the brushes; if the brushes are damaged or worn majorly, they will need to be replaced.
  5. If the brushes appear to be in good condition, continue to the next test. Leave the brush assembly removed for the next test.

II. Rotor Test

  1. With the brush assembly removed, and using a multimeter, set the tester to the "Ohms 1k" scale. With the probes of the tester, touch each copper slip ring and there should be a reading between 45 and 75 ohms. (This test should be performed with the generator not running and turned off. If the ohms reading is less than 45 it will mean that the rotor is failing and will need to be replaced).
  2. If the reading is not between 45 and 75 ohms, examine the soldering of the rotor wiring to the slip rings. Be sure all solders are solid and completely connected.
  3. If the ohm reading is within the appropriate range, continue to the next test. Put the brush assembly back in place, attach the support plate, and secure it with the bolt previously removed. Leave the yellow end cover off for the next test.

III. DC Output from AVR to Brush Assembly

  1. Check the red wire and white wire on the brush assembly and be sure they are pressed on snugly.
  2. With a multimeter, set the scale to "DC Volts," and place the probes on the red and white wires. There should be a voltage reading between 15 and 18 volts DC. (This test should be performed with the generator running and turned on. If you reading is below 15 volts DC, continue to the Excited Field test before replacing the voltage regulator [AVR]).

IV. Exciter Field Winding Output

  1. Locate the white nylon connector with four wires coming the stator which also connects to the AVR, and disconnect the plug.
  2. Of the four wires, find the two yellow wires and the terminal they are plugged into on the nylon plug. With the engine running and using a multimeter, set the scale to "AC Voltage" and using the meter probes: Touch the terminals. The meter should read between four and eight volts AC. (This test should be performed with the generator running. When testing a generator over 3500W, test the two blue wires for AC voltage. [The exciter field windings are the blue wires]. When touching the probes to the terminals, there is no specific direction the probes need to be placed. If the meter reading does not fall between four and eight volts, the stator will need to be replaced; there is a small chance that the stator has not failed and one of the magnets on the rotor has either come loose, cracked, or has broken. Before ordering parts, remove the stator from the rotor and examine it thoroughly. If the meter is reading between four and eight volts, the voltage regulator (AVR) will need to be replaced.

View and download the PDF version here.

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