Skip to content
Open sponsorship. Site bar + newsletter spot, US$50/week.
GENERATORCODES

Home / Cummins / 12

RS home standby display

12

Overvoltage

Electrical · Shutdown

Fault code 12. The RS20 manual's possible causes are generator-set loads, wire connections, and windings. The corrective action printed is to have the unit serviced by an authorized Cummins Onan dealer.

Seen on: Cummins RS-series home standby sets covered by the RS20 operator manual. QuietConnect RS13A–RS20AC operator manual A053X174 repeats these fault code numbers.

Likely causes

  • Output voltage high enough for the controller to shut down.
  • Windings or sensing connections the manual groups under this code.

Checks an owner can do

The cited source does not list a homeowner check for this fault. Leave the set off and use the note below.

When to call a pro

Turn the generator breaker off and leave the set stopped. Overvoltage is a dealer repair in this manual.

Source

Cummins RS20 home standby operator manual, section 5 (fault codes and blink pattern). The same code numbers are listed in operator manual A053X174 for the RS13A, RS17A, RS20A, and RS20AC QuietConnect sets.

Wording follows that document. Firmware can change a threshold. If this page and the manual shipped with your unit disagree, follow the manual.

What fixed mine

No approved reports for this code yet. Send one. It stays in the review queue until it is approved.

Related Cummins codes

https://generatorcodes.com/brand/cummins/12