Generator Tests (NFPA 110)

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ed downey

Senior Member
Location
Missouri
I was wondering if anyone could help me out with the testing requirements as called for in NFPA 110 (Standards For Emergency Power & Standby Systems)

I WOuld Like To Know What Is Specifically Called For In This Publication.
 

bennie

Esteemed Member
Re: Generator Tests (NFPA 110)

I don't have the publication, but have tested many generators. What is the specific point of not understanding?
 

ed downey

Senior Member
Location
Missouri
Re: Generator Tests (NFPA 110)

Bennie,
I am looking for the requirements spelled out in this publication.

Does it say to test at 25% load for 30 minutes then at 50% for 30 Minutes then At 75% for 30 Minutes Then at 100% for 240 Minutes.

I am just wondering what the specifics of this document are.

Thanks,
Ed
 

bennie

Esteemed Member
Re: Generator Tests (NFPA 110)

Ed. You will need a dummy load bank to perform the tests. I always connected a dual trace digital scope to look at the sine wave, during the test.

The test is to determine speed stability, and comparison of temperature readings.

There is many companies who specialize in the tests. It is much easier to hire one of them.
 

rich000

Senior Member
Re: Generator Tests (NFPA 110)

I agree with Bennie. Before I struck out on my own to do "real" electrical work, I was involved with a consulting company that did commissioning for data centers (switchgear, gens, UPS, etc.).

Unless you have the equipment and experience, it is worthwhile to hire a testing company.

Also, if you are the installer, it looks better to the customer to have an indendent testing agency do the testing rather than yourself.
 

enerconn1

Member
Re: Generator Tests (NFPA 110)

First thing how many Generators do you have if you have 2 or more than you must have paralleling gear, if so than run your building as a load for specific times and switch loads on Generators because the load banks are not cheap. I beleive your money can be spent on haveing a tech go through them whileyou use your building as load.
 

rich000

Senior Member
Re: Generator Tests (NFPA 110)

Typically, you cannot 100% load test a generator with building load.

The generator should be sized greater than 100% building load (for future consideration, motor startup current, etc.).

Rent the loadbanks or call a testing agency.
 

websparky

Senior Member
Location
Cleveland, Ohio
Re: Generator Tests (NFPA 110)

Hi Ed,

Send me an email or private message, I have the NFPA 110.

Dave

[ July 18, 2003, 11:34 PM: Message edited by: websparky ]
 

flightline

Senior Member
Re: Generator Tests (NFPA 110)

Ed,

Hopefully you were able to hook up with websparky, but if you did not, or for others reading the thread, I'll try to post something herein.

If you are referring to original installation acceptance, then this is spoken to in 7.13 of NFPA 110. It is also important to clarify if this is a Level 1 systen, [life safety], and Level 2, [required system but for more "elective" load types].

For a Level 1 or 2 Acceptance test, 7.13.4.1 dictates that from a "cold" start, with the emergancy load at a standard operating level, a normal source power loss shall initiate the system. At that time, a number of parameters must be recorded and must continue for a period of time as stated in table 4.1(a) of NFPA 110, dependant on the "Class" of the system.

After this test is complete, 7.13.5 states the system shall be allowed to cool for a period of 5 minutes.

After this 5 minute period, 7.13.6 and 7.13.7 state that a full load test, equal to 100% of the kW rating of the system be applied for a period of 2 hours. During that time, operating parameters must be recorded at 15 minute intervals. Part of the load may be the building load with the remainder being supplied by a load bank.

Paraphrasing 7.13.6.1, this test may be accomplished by a load bank totally, with unity power factor, such as the common resistive load bank. This is actually how we have done all of our acceptance testing.

7.13.7 speaks to the test some more or in other terms, and mentions such things as starting my be accomplished by any method that initiates the prime mover, and picks up the 100% load in 1 step.

With respect to operational tests or exercising, is spoken to in a number of sections, including 8.3.2.1 and 8.4.2. In 8.4.2 states for Level 1 & 2, that these systems be tested at least once monthly for 30 minutes minimum at a not less than 30% of namplate kW rating.

I think that this is the section you were questioning, since 8.4.2.3 states that diesel -powered emergancy power systems that do not meet the requirements of 8-4.2, [which I interpret to mean non-required systems], shall be exercised monthly with the normal connected loads, and then anually with supplemental loads of 25% of nameplate for 30 minutes, then 50% for 30 minutes, then 75% for 60 minutes, for a total of 2 hours total load test.

8.4.3 states that these tests shall commence from a cold start.

As an aside, here at the airport, many of the geneerators installed for spot loads have resistive load banks permanently connected. They have a controller that exercises with as much normal connected building load as may exist, and uses this controller to bring in as much other resistive load via the bank to get to 90-100%.

The gentleman I work with is a mechanical engineer that at one time, ran the Chicago & Northwestern Railroad's repair shops. He has guided me in working with these diesel engines. He explained that a diesel engine that does not get exposed to full loading, such as a genset spinning without load or a truck idling will "polish out" it's cylinders allowing for a problem called "wet-stacking" by which, unburned fuel gets blown up the exhaust stack.

Most generator suppliers have and can include as part of their generator quote, load bank testing.

There a a couple of links to some load bank manuacturers. They are Avtron and Simplex.


I hope this helps, Gregg

[ July 22, 2003, 10:42 AM: Message edited by: flightline ]
 

roger

Moderator
Staff member
Location
Fl
Occupation
Electrician
Re: Generator Tests (NFPA 110)

For anyone interested you can check into Dan Chisholm's seminars and books. He covers all the good info on EPSS's.

Look here http://www.mgi-hcn.com/Seminars.htm

click on his bio for the books.

Roger
 
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