Maintenance and testing are critical to the continued reliability of your emergency generator and must be performed in accordance with manufacturer’s recommendations, instruction manuals, and the minimum requirements of NFPA 110. 

Your facility should have at least two sets of instruction manuals for all major generator components. One set should be kept in a secure, convenient location near the equipment. 


11.1.1 Registration Renewal

Registration to be renewed every 3 years with the Department of Environmental Protection (DEP). The DEP will issue a registration application to the building owner. 

11.1.2 Testing

Monthly and annual generator tests are important measures for preparing generators for power outages, but they should not be the only measures.

Every 3 years the NFPA 110 emergency generator testing must be performed by building owners and perform retrofitting, as necessary.

NFPA 110 does not establish a specific date and time of day for required testing. Those are to
be determined by management and are typically scheduled so as to provide minimum
disruption of facility operations.


  • Testing must be continuous for the duration of the generator’s assigned class, but is not required to exceed 4 hours
  • The test must be initiated by operating at least one transfer switch test function and then by operating the test function of all remaining ATSs or initiated by opening all switches or
    breakers supplying normal power to all ATSs that are part of the EPSS being tested.
  • The minimum load for a diesel-powered emergency power supply (EPS) must be not less than 30 percent of the standby nameplate kW rating of the generator. A supplemental load is allowed to be used to meet or exceed the 30 percent requirement.
  •  The minimum load for a diesel-powered EPS must be that which maintains the minimum exhaust gas temperatures as recommended by the manufacturer.