Prestige Generator Service

A generator requires tests that measure its ability to produce electricity during a power outage. Often, these tests are performed by a service that specializes in Emergency Power Supply System (EPSS) maintenance. The focus of this article is load testing, which consists of operating a genset under available and/or artificial load to measure its operating efficiency, or to resolve a condition known as wet stacking. If you need these services, using an independent generator service instead of a manufacturer is the best option. In addition to offering lower prices and better response time, an EPSS service focuses on maintenance and testing, whereas manufacturers focus on development and sales.

If you need emergency power testing, schedule a free consultation with a generator service as soon as possible, especially if your building contains a level 1 generator.

The Need for Load Testing

Load testingtests generator efficiency by measuring whether it operates at a certain percentage of its nameplate kilowatt rating. generator service. The first line of load testing is a monthly test that is performed under National Fire Protection Association (NFPA) code 110 guidelines. To pass the monthly test, a genset must operate under available load and (a) operate at a minimum of 30% of its nameplate kilowatt rating; or (b) achieve the minimum exhaust gas temperature for monthly testing, as stated by the manufacturer.

If the genset fails to achieve one of these criteria, NFPA 110 states that it should be tested each year under artificial load - a test that requires a loadbank. During load bank testing, the genset is tested for two continuous hours in the following manner:

  • 30 minutes at 25% of the nameplate kilowatt rating
  • 30 minutes at 50% of the nameplate kilowatt rating
  • 60 minutes at 75% of the nameplate kilowatt rating

Load bank testing can increase generator efficiency; it can also resolve wet stacking - a condition in which unburned fuel becomes trapped on a generator's exhaust side. By causing a generator to operate at a certain percentage of its nameplate kilowatt rating, load bank testing can cause the unburned fuel to evaporate. If it is not evaporated, it can cause parts to wear prematurely.

A Special Test for Hospitals

The NFPA testing guidelines above apply to level 1 and level 2 generators. Hospitals contain level 1 generators. But they must be tested according to JCAHO(Joint Commission on Accreditation of Healthcare Organizations)guidelines, in addition to NFPA guidelines. While being tested monthly and, if necessary, annually, generators in hospitals that are JCAHO accredited must be tested triennially for four continuous hours. Throughout the test, a generator must operate at a minimum of 30% of its nameplate kilowatt rating.


If you need generator and load testing, an independent generator service can conduct monthly, annual, and triennial generator tests. If you need emergency power testing, do not wait for a power outage to make the need more apparent. Call a generator service that performs generator and load testing today.

Prestige Generator Service
United States
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