WEN 3500 Generator Parts Instructions - Manual (Page 3)

The Brushes make connection with the Rotor by riding on the Slip Rings. With the Brush
Assembly removed you should clean the slip rings of carbon build-up using rubbing alcohol
and a rag or, in severe cases, emery cloth.
Reinstall the Brush Assembly by aligning it with the index post on the Housing and tightening
the 7mm screw. It is normal for the Brush Assembly to be slightly tilted but the carbon should
make good contact on the Slip Rings.
With the Brush Assembly in place you can test the exciter voltage by starting the Generator
and reading the output to the brushes with a DC Voltmeter.
Typical exciter voltage readings are 10 to 12 Volts DC.