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How to avoid wet stacking

Updated: Sep 16, 2022

If you have not heard of wet stacking, you could be forgiven in thinking it had something to do with storing damp firewood. Well, it has nothing to do with it. Wet stacking is all about generators and a problem that can occur when your genset is not properly maintained.

No matter which industry you’re in, it’s important to safeguard your commercial well-being with an industrial generator that’s ready to meet your needs.

When left unattended for lengthy periods of time, your backup diesel generator can be subject to a detrimental process called wet stacking. Here are some tips for determining if wet stacking is happening in your generator and what you can do about it.

What Is Wet Stacking?

Wet stacking is a condition that occurs when your unused diesel fuel, accumulated moisture, and carbon particles are allowed to gather in the exhaust of your generator. This can happen for a number of reasons but usually results from diesel fuel not being properly burned off during use. As a result, a dark muddy liquid congeals in the generator’s exhaust stacks — hence the term wet stacking.

What Causes Wet Stacking?

Wet stacking can occur as a result of several issues. However, the primary reasons are:

  • Letting your generator sit unused for long periods of time

  • Allowing your generator to run under its designed operating temperature

  • Allowing your generator to run at less that 60% of its rated output

  • Running your generator with an incorrect air-to-fuel ratio

  • Having too little fuel in your generator

Wet stacking is hazardous to genset injectors, exhaust valves, and other functional features. And, when left untreated, wet stacking can inhibit the performance of your generator as well as significantly reduce the lifespan of your unit.

How Can I Fix Wet Stacking?

Fortunately, there are ways to address wet stacking before it requires extensive maintenance.

Avoid It Entirely

It’s worth mentioning that wet stacking is avoidable by following two simple rules: run your generator for a few minutes once a week under load, and make sure a qualified technician services your genset at regular intervals.

Run Your Genset for a while

If you discover wet stacking within your unit early enough, you can fix it by running your generator at its properly designated operating temperature with a 75 percent load. If there is no load present, a 'dummy load' can be applied to the generator using a portable load bank. Contact Pace Power & Air for further information on load testing generators.

Trust the Pros With Years of Experience

That being said, your best bet when combating the ill-effects of wet stacking is to contact a professional who can accurately assess your generator needs.

When your generator is a victim of wet stacking or any number of potential genset issues, contact Pace Power & Air and let one of our skilled technicians make sure your generator is running, and will continue running, at peak performance.

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