Running your generator on 100% building load provides the following two main benefits:

1. Gives you confidence in your power protection system knowing that it will be able to support your entire operations 24/7 whenever you need it to.
2. Prevents wet stacking (provided the building load is sufficient to make the generator run at temperature), which consists of unburnt fuel residue accumulating on the exhaust side of the turbo and into the exhaust system. If left unchecked, this can cause irreversible damage to the diesel engine.

It is recommended to run your generator on building load for at least 4 hours a year. Many businesses do a monthly onload test, which is quite acceptable and means that the entire system is tested 12 times a year but it is still recommended that at least one of the onload tests involves letting the generator run for a minimum of 2 hours rather than the typical 15 minutes.