Although critical facilities are designed to avoid single point of failures, there are many combinations of events that can bring down even the best-designed facilities.  These events most often are a result of poorly, or improperly, maintained equipment.  Generators are your first level of defense when utility power goes down, how confident are you that your generator is going to kick in, and run efficiently?  Just like a car, if a generator sits around unused for too long it may have difficulty starting up when it is called upon.

There are many factors that could contribute to a generator spitting and churning instead of running like a well oiled machine.  Some common reasons generators fail are: bad fuel (bacteria love diesel fuel and will form a layer of sludge on the bottom of your tank if given the opportunity), poor ventilation, and insufficient or poor oil pressure.  Most failures can be predicted and corrected with routine maintenance and testing.  But, to truly see how a system will respond in an emergency situation most experts agree that a generator should be run under full load, at least once a year.   Most generator service providers offer load bank testing as a way to exercise a system under full load.  Below we have offered some information to better help you understand what is involved with load bank testing. 

What is load bank testing?

The load bank test allows a generator to mimic how it will respond when called upon in an emergency situation.  A standby generator is tested and exercised to verify its overall reliability, and its ability to run at its full rated KW output. Typically, a generator is running at a level far less than the units rated output capability.  A load bank test checks the engines ability to perform and provide the required horsepower when called upon in an emergency.  When a load bank is used, the artificial load it provides brings the engine up to an acceptable operating temperature.  

What is no load testing?

We have found that most generators, supporting data centers, are exercised weekly un-loaded, and are very rarely tested with building loads; relying on the occasional utility loss to do the testing.  For diesel engine driven generator sets this can cause 'wet stacking'.  Wet stacking is when unburned fuel accumulates in the engine exhaust.  This is caused by under loading a generator. When running a generator for short duration outages while under loaded, the engine may not reach its optimum operating temperature.  If this is allowed to continue over long periods of time the unburned fuel accumulates, and can become harmful to the engines efficiency and life span.

What are the benefits of load bank testing?

Load bank testing allows the engine to reach its full operating temperature and 'burns out' the accumulation of un-burnt fuel. The result is a unit that runs cleaner and more efficiently.  It also offers peace of mind that your standby generator is operating as it was designed to run. Any generator set, whether the prime mover is diesel or gaseous fuel, can benefit from being load bank tested.

What impact will a load bank test have on my facility?

Load bank testing does not cause any interruption to your facility loads.  The service is in no way intrusive.  Most manufacturers agree a generator set that is frequently run lightly loaded, or never loaded at all, can benefit from being load banked on a yearly basis.

What is tested and monitored during the load bank test? 

During the load bank test EEC monitors critical engine parameters such as; oil pressure, engine temperature, fuel pressure, etc.  We record these readings to show that once the unit reaches full rated load it runs at normal operating temperatures and pressures.  EEC provides a full report of the readings including generator output readings such as; voltages, amperages, KW amounts, etc.

We offer load bank testing as a separate service, or it can be built into your contract and made part of your scheduled, and budgeted, yearly maintenance on your standby power system.  The load bank test can be done during a regularly scheduled PM visit, or we can schedule it during a separate visit.