Generator Load Bank Tests

Q: Do generators for healthcare need to be load-bank tested annually if they meet the 30% nameplate load requirement during each monthly test?

A: No. Load bank testing is only required when any monthly load test fails to achieve 30% of the nameplate rating of the generator. Then, an annual load bank test is required of 50% load for 30 minutes and 75% load for 60 minutes. A 3-year 4-hour test is required, and the load is a connected load from the facility and must reach a minimum of 30%. A supplemental load may be used if the connected load cannot reach 30%.

Temporary Emergency Power Generators

Q: We are going to have temporary generators onsite for two months that we will use during our construction project to replace the main power distribution gear for our bed tower, installing new substation and distribution gear. During the time we will have 10 shutdowns from 4 hours to 12 hours at a time. We will be on the regular emergency power generators and ATS’s normally and only on the temporary units for the shutdowns. This affects normal critical and life safety circuits. Do we have to do monthly generator, and ATS transfers on the temporary units or would the shut downs count for testing? And for annunciation, we are planning to have the generators manned anytime they are in operation with no other temporary remote annunciation. Is this permissible?

A: These are all good questions, and I can provide you with answers on how I would approach this, but ultimately you need to talk with your state, local, and accreditation AHJs in order to get their opinions. Their opinions count and mine does not.

But since you asked, the accreditation organizations already allow an actual emergency event when the generators operate to count as one of the monthly load tests, provided the emergency event meets all of the requirements for a monthly load test. Therefore, I do not see any difference if the temporary generators operate or the regular emergency generators operate during an emergency event. So, I would say you still need to conduct monthly load tests on the generators (normal and temporary units), but an emergency event can count as one of the monthly load tests if it meets all of the requirements for a monthly load test.

I would think an ILSM on the annunciation issue should be sufficient, rather than running a temporary annunciation panel.

Generator Battery Conductance Test

As you may be aware, you are now permitted to have maintenance free batteries to start your generators. Previous to the adoption of the 2012 edition of the Life Safety Code, the editions of NFPA 110 that had been adopted did not recognize sealed lead acid batteries for use to start the generators. Many AHJs did not accept the maintenance free batteries and made the healthcare facilities remove them.

But that is in the past. According to the edition of NFPA 110 that is now adopted (2010 edition), section 8.3.7.1 says maintenance of lead-acid batteries shall include the monthly testing and recording of electrolyte specific gravity. However, battery conductance testing shall be permitted in lieu of the testing of specific gravity when applicable or warranted. When you have maintenance free batteries you cannot get to the electrolyte to conduct the specific gravity test, so you perform the conductance test.

Electrical conductance in a battery is measured by siemens (symbolized S) and is the Standard International (SI) unit of electrical conductance. The electrical conductivity units are siemens per metre, S⋅m-1. The siemens also used to be referred to as a mho – this is the reciprocal of an ohm, and this is inferred by spelling ohm backwards. Conductance is the reciprocal of resistance and one siemens is equal to the reciprocal of one ohm.

Surveyors are now citing healthcare organizations when you fail to perform the conductance test when you cannot perform the specific gravity test on the electrolyte. You will need to have a special meter (like the one in the picture) that measures siemens (or mhos) and the common volt meter is not capable of performing this test.

Make sure you record this reading on a monthly basis.

 

 

 

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.

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 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.

Generator Load Tests

Q: Is it allowed to combine the 3-year 4-hour generator load test along with the annual 2-hour load test? Our generator test company plans on running the generator at 50% load for the first two hours and then elevate to 75% load for the last two hours. In your opinion would this satisfy both the 2 hour and the 4 hour load test?

A: You are allowed to combine the 2-hour load test and the 4-hour load test. The 2-hour load test is required to be conducted once per year when the generator cannot meet the load test of 30% of nameplate rating every month. When this occurs, you still conduct the monthly load tests but once per year you need to conduct a 2-hour load test (usually by connecting the generator to a resistive load bank) that consists of the following sequences:

  • 25% load for 30 minutes, then
  • 50% load for 30 minutes, then
  • 75% load for 60 minutes for 2 continuous hours.

The scenario that you described allowed 50% load for the first two hours and then a 75% load for the last two hours. This would be acceptable in meeting both test requirements since the percentages listed in the standards are minimum settings, and you are permitted to exceed them. But you need to be careful, because if you combine these two tests and start out at 25% load (as required for the 2-hour load test) for the first 30 minutes, then you are out of compliance with the 4-hour test, unless you run an extra 30 minutes after you reach or exceed 30%.