What causes wet stacking in diesel generators and how is it prevented?

Wet stacking occurs when a diesel generator runs under light load for extended periods, preventing the engine from reaching optimal combustion temperature and causing unburned fuel and carbon to build up in the exhaust system. It's prevented by periodically running the generator under a higher load, either through actual site demand or a load bank test, to burn off this buildup. Generators oversized for their actual site load are particularly prone to this issue. Sparkline Group advises on correct generator sizing specifically to help avoid wet stacking problems.