ACF Standby Systems Blog

Category archive: Generator Failure

My Standby Generator Failed! What Happened?

Of course you want your standby system to be there for you when the power goes out–after all that is the only reason you bought it. But every once in a while we find that people have trouble getting what they need from their generator. Power goes down and the generator fails to do its job. As frustrating as this is, there is always a reason for the failure. Generally speaking, there are some reasons that come up more than others when we are talking about generator failure.

  1. The Battery- The number one reason that generators fail is the battery. Just like your car’s engine, your generator’s engine cannot start up without a boost from its battery. Sulfate build-up on the connecting components causes most battery failure. This build-up happens because chemicals in the battery acid discharge sulfate. The sulfate cakes up on the battery, ruining connections and ultimately the battery itself. Another common reason is that the battery loses its charge. Often after maintenance or use, people forget to make sure the battery is set to charge during down time. If the battery does not charge, it loses power and will not be ready to work when you need it.
  2. Coolant Levels- Leaks are usually the culprit when it comes to low coolant levels. Without enough coolant your generator engine will overheat and fail. Ensuring that coolant levels are correct is an important step in the maintenance process.
  3. Fuel Leaks- Aside from coolant, your generator needs fuel to run. Fuel can leak in a couple of ways. The most obvious way is a crack somewhere in the fuel tank or fuel system. Fuel system leaks are generally caused by hoses that are too old and need to be replaced. When it comes to generators, there may be a different type of leak. “Wet stacking” happens when your generator provides itself too much fuel when it is working at a low output level. The extra fuel ends up in the exhaust system. After this happens for a while, the exhaust system has too much fuel in it to properly do its job. The excess fuel will cause the generator to fail. Once again, maintenance can make sure you avoid these issues.
  4. Air in the Fuel System- Just like fuel in the exhaust is bad, air in the fuel will also leave you in a bad spot. There are several types of generator fuel; air is not one of them. If air ends up in your fuel system, your generator will not have what it needs to run. Regularly making sure that fuel is changed or added to will help you avoid this problem.
  5. Human Error- As people, we sometimes make mistakes. When it comes to generators, human errors can complicate things easily. Forgetfulness is the number-one cause of human error. People forget to add fuel or to make sure that the breaker is set to provide power. They also forget to set the transfer switch so that the generator automatically takes over when power goes down. Any of these basic mistakes will cause generators to fail. In a power outage your staff will likely not think about these basic factors and will think that the failed generator is broken. Remembering to cover the basics in advance will pay off when you need backup power.

Hopefully you never experience generator failure. A little knowledge and proper maintenance will usually make sure that you don’t. If you do the advice of an experienced professional is the best way to go.

ACF Standby Systems
Electrical Construction and Maintenance
Association for Facilities Engineering