Many people choose a diesel engine as their backup generator, which is an affordable and efficient independent power source. However, diesel generators also come with one particular danger: wet stacking.

What Is Wet Stacking?

If your engine is only run under low loads, it never attains the internal combustion temperature needed to fully burn the fuel that’s delivered to the system. Unburned fuel within the cylinders turns into vaporized fuel and little particles of soot which recombine to form an oily sludge. These wet deposits cycle through the system and are seen dripping from the exhaust, causing all kinds of problems along the way.

How Does It Affect Your Generator’s Operation?

• Gums up the injector’s ability to deliver fuel


• Contaminates engine oil


• Wears down valves


• Slows down turbo efficiency due to deposits on blades

If wet stacking isn’t prevented or corrected in a timely manner, it can greatly shorten the life of your generator, or necessitate a major overhaul of the engine. This is one of many reasons that regular, qualified generator maintenance is so essential to keep your business operations and premises safe. Because preventing wet stacking is such an issue, organizations such as the NFPA (National Fire Protection Association) and the JCAHO (Joint Commission on Accreditation of Healthcare Organization) have issued strict maintenance standards that prevent damage and accidents that can result from wet stacking. Local municipalities and counties will also have particular codes and standards.

How Can You Prevent Wet Stacking?

At an initial setup stage, you can prevent wet stacking down the road by properly planning your energy system with a suitable load and capacity, so that you don’t frequently run a diesel engine below its recommended load. However, many organizations plan for expansion, and so regular load banking is necessary to ensure that the engine runs cleanly. Load banking allows us to run an engine at a higher recommended capacity (usually up to 80%) with predictable rates and stages, for a designated amount of time, without interrupting the normal function of your business. During this time, we can closely monitor the operation of your generator, and clean out the unburned fuel that can eventually lead to wet stacking.

Here at Gen-Tech, we offer portable load bank testing at up to any size generator, all conducted utilizing strict procedure dictated by regulating authorities, so that we can provide you with a detailed report about the operation of your generator. Depending on how you use your generator, load bank testing may be necessary every quarter, 6 months, or 12 months. Do you have any questions about load banking, regular generator maintenance, or the risks of wet stacking? Give the generator pros at Gen-Tech a call today.