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GENERATORCODES

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15–20 kW standby control board

5

Low frequency

Engine · Shutdown

Service code 5. The display scrolls Low Frequency. This chapter says the set shuts down if the engine runs slower than 55 Hz for three seconds, and that the remote LED flashes five times. Causes listed: a failed engine component, electronic governor trouble, excessive load, a restricted air filter, generator sense wiring, the fuel system, an engine that cannot make enough power, or the control panel. The frequency spec it uses while testing is 58.5–61.5 Hz (3600 rpm ±100).

Seen on: Briggs & Stratton 15 kW and 20 kW standby generator systems covered by manual 381268GS Rev. A.

Likely causes

  • Too much load.
  • Restricted air filter or a fuel-delivery problem.
  • Governor, sense wiring, or a weak engine.

Checks an owner can do

  1. Turn off large loads.
  2. With the engine stopped, replace an air filter that is visibly blocked, using the filter the owner manual calls for.

When to call a pro

Measuring frequency at the breaker, and governor or throttle work, are the manual's technician tests. Do not adjust the stepper linkage. To reset the service-code system, the manual says to hold OFF until the display stops scrolling the code, hold OFF at least 7 more seconds until the display turns off, leave it off at least 30 seconds, correct the cause, then hold AUTO and reinstall the 15 amp fuse if you removed it.

Source

Briggs & Stratton Service & Troubleshooting Manual, Standby Generator System 15 kW–20 kW, manual 381268GS Rev. A (service code list and the matching code chapters).

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 Briggs & Stratton codes

https://generatorcodes.com/brand/briggs-stratton/5