How Do I Know if My Generator is Overloaded?

If you notice that your generator is emitting oily smoke or dripping a black substance from the exhaust pipes, it doesn’t take an expert to recognize that this is a big problem. Understanding the cause and solutions, though, takes a little bit more understanding.

It’s likely that a generator dripping liquid out of the exhaust system is doing something called wet stacking. Wet stacking just means that something has gone wrong with the operation of your generator, causing unburned fuel, soot or carbon, and accumulated moisture to drip out of the exhaust pipes or “stacks”.

What are the causes of wet stacking?

Diesel engines require hot, compressed air to ignite the fuel. If the air doesn’t reach the proper temperature, the engine won’t run correctly and the fuel won’t burn the way that it should – resulting in wet stacking.

This issue can be caused by a variety of factors. For example, wet stacking might occur if the fuel level in the engine isn’t right. A certain ratio of air to fuel is required for proper operation, and if the fuel level is too low, the ratio is incorrect and will cause further problems.

The generator not running at the proper temperature could also be a result of cold conditions. If your generator is outside during the winter, or just in a cold environment, it will most likely have a more difficult time reaching the ideal temperature.

Your generator must be able to maintain the designated operating temperature as well. If it’s having issues with maintaining this temperature, wet stacking is likely to occur.

Finally, your generator might experience wet stacking if it’s been sitting unused for a long period of time.

What are the effects of wet stacking?

Most obviously, the engine will be coated in the mixture of unburned fuel, soot and moisture that drips out of the exhaust pipes. Fuel deposits will accumulate inside of the engine, damaging the exhaust system, injectors, piston rings and more.

The performance of the engine will also be negatively impacted due to pressure issues. An engine that has been wet stacking will not be as powerful and will not emit as much power as it should, because it’s running less efficiently.

Wet stacking emissions are an environmental hazard, and while this may not be catastrophic for a home generator, the smoke and liquid might result in fines depending on your area.

Possibly the most serious outcome of wet stacking is the premature wear on the engine itself. If allowed to continue for too long, wet stacking can take years off of the life of the generator, necessitating a replacement much sooner. It can also require much more frequent and expensive maintenance during the remaining time that the generator is functional.

How can I avoid wet stacking?

The most important way to prevent wet stacking is to simply increase the operating temperature by applying additional load. You can do this by increasing the amount of power that is being generated. This could mean plugging in more appliances– anything to increase the power output without overloading the engine. Ideally, the generator should be running at 50% load or higher, with 30% load as an absolute minimum.

You can also avoid it by making sure to frequently use your generator. Letting it sit unused or idle for too long, or even letting it run at too light a load for too long, will greatly increase the likelihood of wet stacking. 

It’s generally recommended to start your generator at least every 30 days, allowing it to run for a short period of time. This periodic use allows oil to circulate through the engine, keeping all of the necessary parts lubricated for smooth operation.

If the generator is located in cold conditions, take special care to ensure that it reaches the proper temperatures. Periodic use of the generator, even if that just means turning it on once a month and letting it run for a while, will make sure that it’s able to reach the correct temperatures for ideal operation.

Maintenance is key

Another important way to prevent wet stacking and other generator problems is to be sure to prioritize regular maintenance. At Northside Power, our generator experts can provide regular and thorough maintenance to your generator. 

We also know that generators are often needed in emergency situations– and needing to power your home during the winter is not the time to realize that the engine is not running how it should. That’s why we offer 24/7 emergency support and service. Give us a call and we’ll get someone out to help you ASAP. Even if it’s not an emergency, we’re still here to answer all your questions to ensure the longest life for your generator, so feel free to reach out anytime.