What will cause a generator to wet stack?

What will cause a generator to wet stack?

• A. Insufficient load
• B. Excess load
• C. Low ambient humidity
• D. Too much fuel

Answer: (A)

Wet stacking happens when a diesel generator is run with insufficient load. At light load, the engine doesn’t reach the temperatures needed for complete combustion, so some fuel passes through the cylinders unburned and ends up in the exhaust. This unburned fuel can condense in the exhaust system, creating a wet, smoky stack. The fix is to apply a proper minimum load (or use a load bank) so the engine operates hot enough for complete combustion. Humidity isn’t a factor here, and operating with too much fuel or at excessive load leads to different symptoms (like rough running or overheating, or rich-burn smoke) rather than the wet, drippy exhaust characteristic of wet stacking.

Wet stacking happens when a diesel generator is run with insufficient load. At light load, the engine doesn’t reach the temperatures needed for complete combustion, so some fuel passes through the cylinders unburned and ends up in the exhaust. This unburned fuel can condense in the exhaust system, creating a wet, smoky stack. The fix is to apply a proper minimum load (or use a load bank) so the engine operates hot enough for complete combustion. Humidity isn’t a factor here, and operating with too much fuel or at excessive load leads to different symptoms (like rough running or overheating, or rich-burn smoke) rather than the wet, drippy exhaust characteristic of wet stacking.