Generator and ATS Testing

Q: I am new in my position and I would like to know what the weekly generator inspection consists of? I also would like to know what the monthly generator inspection and transfer switch testing consist of?

A: Some of this depends on your accreditation organization. Not all AOs survey generators the same way. So I will provide you with what the Life Safety Code requires, with the understanding you need to check with your AO to determine if they have additional requirements. The following information is derived from NFPA 110-2010, which says the routine maintenance and operation testing program must be based on the manufacturer’s recommendations and instruction manuals (section 8.1.1):

Weekly Inspections:

  • Inspection per manufacturer’s recommendation
  • Storage batteries, including electrolyte levels or battery voltage, used in conjunction with systems must be inspected weekly and maintained in accordance with the manufacturer’s specifications. (8.3.7)
  • Emergency Power Supply Systems (EPSS), including all appurtenant components, must be inspected weekly. (8.4.1)

Monthly Inspections:

  • Maintenance of lead-acid batteries must include the testing and recording of electrolyte specific gravity, Battery conductance testing is permitted in lieu of the testing of specific gravity when applicable or warranted. (8.3.7.1)
  • Emergency Power Supply Systems (EPSS), including all appurtenant components, must be exercised under load at least monthly. (8.4.1)
  • Diesel generator sets in service shall be exercised at least once monthly, for a minimum of 30 minutes, using one of the following methods (8.4.2):
    • Loading that maintains the minimum exhaust gas temperatures as recommended by the manufacturer
    • Under operating temperature conditions and at not less than 30 percent of the EPS nameplate kW rating
  • Diesel-powered EPS installations that do not meet the requirements of 8.4.2 shall be exercised monthly with the available EPSS load and shall be exercised annually with supplemental loads at not less than 50 percent of the EPS nameplate kW rating for 30 continuous minutes and at not less than 75 percent of the EPS nameplate kW rating for 1 continuous hour for a total test duration of not less than 1.5 continuous hours (8.4.2.3).
  • Spark-ignited generator sets shall be exercised at least once a month with the available EPSS load for 30 minutes or until the water temperature and the oil pressure have stabilized (8.4.2.4).

Annual Test:

  • A fuel quality test must be performed annually in accordance with ASTM D 975 Standard Specification for Diesel Fuel Oils.

3-Year Testing:

  • Level 1 EPSS shall be tested at least once within every 36 months (8.4.9)
  • Level 1 EPSS shall be tested continuously for the duration of its assigned class (8.4.9.1).
  • Where the assigned class is greater than 4 hours, it shall be permitted to terminate the test after 4 continuous hours (8.4.9.2).
  • The test shall 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 (8.4.9.3).

Automatic Transfer Switches:

  • Transfer switches shall be operated monthly (8.4.6).
  • The monthly test of a transfer switch shall consist of electrically operating the transfer switch from the standard position to the alternate position and then a return to the standard position (8.4.6.1).

Circuit Breakers:

  • EPSS circuit breakers for Level 1 system usage, including main and feed breakers between the EPS and the transfer switch load terminals, shall be exercised annually with the EPS in the “off” position (8.4.7).
  • Circuit breakers rated in excess of 600 volts for Level 1 system usage shall be exercised every 6 months and shall be tested under simulated overload conditions every 2 years (8.4.7.1).
  • The routine maintenance and operational testing program shall be overseen by a properly instructed individual.

Spark-Ignited Generators

Q: I have two questions regarding spark-ignited emergency power generators:

  1. What maintenance tests are required for natural or propane Generators?
  2. Are load bank test required for Natural gas or Propane gas powered generators.

A: Monthly tests, but since they are spark-ignited generators they do not have to meet a particular load. They just have to operate with the available EPSS load for a minimum of 30 minutes or until the water temperature and oil pressure have stabilized. (See section 8.4.2.4 of NFPA 110-2010).

No, spark-ignited generators are not required to have an annual load bank tests. An annual load bank test is required when diesel powered generators cannot meet the minimum load of 30% of the nameplate rating (in kW) during each monthly load test. Spark-ignited generators are exempt from having to meet this requirement.

A 3-year 4-hour load test is required for all generators, including spark-ignited generators. But you are not permitted to use a load bank on spark-ignited generators. The 3-year 4-hour load test must operate using the load from the ATS. For spark-ignited generators, the load is permitted to be the available load. (See section 8.4.9.5.3 of the NFPA 110-2010.) Load banks are not permitted for the 3-year 4-hour load test for spark-ignited generator.

Generator Starting Batteries

Q: I’m getting conflicting answers as to when generator batteries need to be replaced. Some say in a hospital they need to be replaced every 5 years unless the hospital is a trauma center then it is every 3 years. I have also been told that it doesn’t matter if it is a trauma center; hospital or nursing home; the batteries need to be replaced every 3 years. Can you please tell me what is correct?

A: The correct answer as to how often generator starting batteries need to be replaced in hospitals depends on which authority having jurisdiction you’re talking to. That may be why you are receiving conflicting answers. The typical hospital has 5 or 6 different authorities having jurisdiction (AHJ) that enforce the Life Safety Code:

  • CMS                                             (Medicare/Medicaid)
  • Accreditation Organization    (i.e. Joint Commission)
  • State health department
  • State fire marshal
  • Local fire inspector
  • Insurance company

Any one of these AHJs may have a requirement for testing/inspection/replacement of generator starting batteries that the other AHJs may not have. The hospital would have to comply with the most restrictive.

First… I cannot find any specific requirements in the NFPA codes and standards for generator starting batteries to be replaced at a different frequency if the generator serves a trauma center or not. But the hospital’s state or local AHJ may have a specific requirement that addresses trauma centers that I am not aware of.

Second… According to NFPA 110-2010, the hospital is required to replace lead-acid batteries used for generator starting every 24 – 30 months. This would be enforced by the CMS standards and the accreditation organization (AO) standards. This is found in the Annex section A.5.6.4.5.1 of NFPA 110-2010, and CMS and the AOs usually (not always) enforces the Annex section requirements of the NFPA standards.

I checked the 1999 edition of NFPA 110 and the Annex section in that edition recommended replacing the batteries every 24 – 30 months, so I don’t see anything in current or past NFPA standards that would support your 5-year frequency to replace generator starting batteries.

NFPA 101-2012 Life Safety Code requires all healthcare occupancies and ambulatory healthcare occupancies to comply with NFPA 110-2010, so this means all hospitals, nursing homes, and trauma centers, would have to have their generator starting lead-acid batteries replaced every 24 – 30 months, according to CMS and AO standards.

I suggest you contact the hospital’s state and local authorities to determine if they have more restrictive requirements.

Generator Annual Load Test

Q: My client installed a generator in a Phase 1 project that does not and will not for some time be able to meet the requirements for the 30% load during the monthly test due to low current loading. As I understand it, 8.4.2.3 in NFPA 110 allows you to do the monthly test as is and do a supplemental annual test yearly as outlined which would then meet the requirement for the monthly test. Is that the proper interpretation as the generator will not meet the 30% requirement until some unknown future date?

A: Yes… section 8.4.2.3 of NFPA 110-2010 is the correct reference when any one of the monthly tests cannot meet the requirement for at least a 30% load. The annual test must be conducted within 12 months of the first monthly test that was incapable of meeting the 30% load requirement, and then no more than 12 months from the last annual load test.

Your client should continue to conduct the monthly load tests (not less than 20 days and not more than 40 days) with the available load. For the annual load test, a supplemental load (i.e. load bank) of not less than 50% of the nameplate kW rating for 30-minutes and a supplemental load of 75% of the nameplate kW rating for 60-minutes must be conducted, for a total test of 90 continuous minutes.

The cool-down period for the generator is not part of this 90-minute test.

Generator Testing

Q: Does our hospital have to test the generator for 30 minutes every week, and then 1-hour once a month? We have programmed our generators to operate every Wednesday at 12 noon and run for 30 minutes. We do ATS test once a month and record information when running.

A: According to section 9.1.3.1 of the 2012 Life Safety Code, emergency power generators must be tested in accordance with NFPA 110. Section 8.1.1 of NFPA 110-2010 says the routine testing of the emergency power generators must be based on all of the following:

  • Manufacturer’s recommendations
  • Instruction manuals
  • The requirements of NFPA 110
  • The AHJ’s requirements

While NFPA 110 does not have any requirements to operate the generator on a weekly basis, there may be manufacturer requirements or AHJ requirements that do. Section 8.4.1 of NFPA 110-2010 specifically says generators must be inspected weekly but operated under load on a monthly basis. Section 8.4.2 requires the monthly load test to operate for 30 minutes. I suggest you check with your generator manufacturer and your state and local AHJs to see if they have specific weekly run-tests of the generator.

Generator Fuel Testing

Q: What are the guidelines on the diesel fuel test for the generator as far as having it treated or a sample sent off for testing?

A: The new 2012 Life Safety Code references the 2010 edition of NFPA 110, the standard for emergency and standby power systems. Section 8.3.8 of the NFPA 110-2010 requires the fuel for the generators to be tested annually for quality. According to more recent editions of NFPA 110, this test is to be conducted in accordance with ASTM D975, Standard Specification for Diesel Fuel Oils. You may purchase a copy of the standard direct for the ASTM website https://www.astm.org/Standards/D975.htm

Generator Testing

Q: We have a generator that doesn’t meet the 30% load for the monthly run so we have to do an annual run with the load at 50% for 30 min and 75% for 60 min for a 90-minute continuous run. Our contractor did the annual run but he ran it with 52 % for 30 min , 75% for 30 min and 81% for 30 min, then he continued to run it for 2½ more hours dropping the percentages as he went for 4 continuous hours at not less than 30%. My question is does these meet the intent of the standards for both an annual and a 3-year load test?

A: Yes… I would say the test as you described meets both the annual requirements and the 3-year test requirements. The generator load testing requirements are minimum load settings, and it is permitted to exceed these minimums.

Generator Testing

Q: In a business occupancy and an ambulatory occupancy do we need to test our generator on load each month or can we do a load bank test once per year?

A: Yes… Monthly load tests are required for emergency power generators at ambulatory healthcare occupancies and business occupancies. According to the 2012 Life Safety Code, sections 20/21.5.1.1 for ambulatory healthcare occupancies and 38/39.5.1 for business occupancies, compliance with section 9.1 on utilities is required (just like healthcare occupancies).

Section 9.1.3 requires compliance with NFPA 110-2010 regarding emergency power generators, and section 8.4.1 of NFPA 110 requires monthly load tests.

Now… there is an exception to all of these testing requirements…. Section 9.1.3 says emergency generators, where required for compliance by the LSC, must be tested and maintained in accordance with NFPA 110-2010. So, if you are not required to have emergency power generators at the ambulatory healthcare occupancy or the business occupancy, then you do not have to maintain them according to NFPA 110.

Generator Testing at Business Occupancies

Q: Does a diesel generator that is located in a business occupancy require the same testing frequencies as the one at our hospital requires?

A: It depends if the generator is required by the Life Safety Code. Sections 38/39.5.1 of the 2012 Life Safety Code says utilities in business occupancies must comply with section 9.1. Section 9.1.3 says emergency generators, where required for compliance with the Life Safety code, must be tested and maintained in accordance with NFPA 110, which is the same standard requirement for healthcare occupancies.

So, the question now becomes, is the generator in your business occupancy required by the LSC? Business occupancies do not automatically require emergency power like healthcare occupancies do. For business occupancies, it depends on a variety of issues.

For new business occupancies, emergency lighting is required where any one of the following is met:

  • The building is two or more stories in height above the level of exit discharge;
  • The occupancy is subject to 50 or more occupants above or below the level of exit discharge;
  • The occupancy is subject to 300 or more total occupants.

For existing business occupancies, emergency lighting is required where any one of the following is met:

  • The building is two or more stories in height above the level of exit discharge;
  • The occupancy is subject to 100 or more occupants above or below the level of exit discharge;
  • The occupancy is subject to 1000 or more total occupants.

When emergency lighting is required it must meet the requirements of section 7.9 of the 2012 Life Safety Code. Section 7.9 does not mandate that emergency lighting be powered by a generator, but section 7.9.2.4 does say if the emergency lighting is powered by generators, then the generators must be tested and maintained in accordance with NFPA 110.

So, if your business occupancies are required to provide emergency lighting, and the emergency lighting is powered by generators, then the generator must be tested and maintained in accordance with NFPA 110, which is the same requirement as hospitals.

Emergency Lights in Generator Rooms

Q: In regards to emergency generator backup lights, I seek clarity how long does the battery have to last? I’m assuming that the battery should be able to be tested annually for 90 minutes like those inside my hospital.

A: Section 7.9.3 of the 2012 LSC is clear: All required battery powered emergency lights must be tested monthly for 30 seconds and annually for 90 minutes. The NFPA 110 requires a battery powered emergency light in the generator room, so it is a required light that needs monthly and annual testing.

The code requires the light to operate for 90 minutes.