Load Bank Testing
Load bank testing is essential to determine if a generator is capable of running at its rated load performance. Most generators at large facilities are over sized and can accommodate the designated load using only a small portion of the power that it is capable of.
Eventually, a buildup of carbon collects on the valves and causes what is known as "wet stacking". This takes place when all of the fuel is not burned in the cylinder. On the exhaust stroke, the unburnt fuel exits in to the exhaust system and is discharged. This can be a result of a generator running under a small percentage of its rated capacity. The build up of carbon prevents the valves from seating properly and also clogs the fuel injectors. This, in turn, decreases the power of the engine and the generator can no longer handle it's rated load.
When a generator is ran under a heavy load the heat that is generated within the cylinders helps prevent carbon build-up by burning all of the fuel. A load bank test is recommended at least once a year and is usually mandatory within health care facilities.