PM testing of electrical equipment and systems

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puckman

Senior Member
Location
ridgewood, n.j.
When doing pm or electrical testing should there be a standard such as NETA or NFPA 70b that the customer should require ? Is there a better method to measure or compare too ? What should the workers [ contractor ] be qaulified or certified to do when suppling this type of service ?
 

zog

Senior Member
Location
Charlotte, NC
70B is not very specific on tests, more of a guide. NETA is a recognized ANSI standard with specific tests and procedures, including specs on what is acceptable or not. The specs are based on other recognized standard for that specific equipment (IEEE, NEMA, etc..)

The whole point of using a NETA company with certified techs is that they are not associated with any manufacturer so it is a true independent 3rd party opinion of the condition of the equipment and recommendations should be unbiased. Using certified techs lets you know they are real testing guys (Tons of training and experience required to even take the exams, which are not easy to pass and proctored by an independent testing facility).

That said, a certified tech is well rounded but may not necessarily be an expert on a specific type of equipment. There are some really good NETA techs out there, and some average ones. There are also other companies that specialize in electrical testing with some very talented people that are not NETA certified (For example I used to be a NETA level IV tech, but no longer work for a NETA company, I did not forget everything when I left). Most testing guys not NETA now, were at one point.

A company does nto have to be an acredited NETA company to use the specs, I would recommend you always specifiy "tested per ANSI/NETA 2009 MTS" when looking for a contractor. IMO there is no better standard to follow, but some of the tests are optional so you need to specify exactly what you want done in some cases (PF tests for dry type transformers would be an example of an optional maintenence test you may want to consider requiring).
 

puckman

Senior Member
Location
ridgewood, n.j.
When PM'S come up it is benifical to use a NETA contractor. Now there needs to be some corrective action taken, is there a certification for some contractors who perform this type work ?
 

zog

Senior Member
Location
Charlotte, NC
When PM'S come up it is benifical to use a NETA contractor.

I thought I explained that in detail in my post. You should require testing to be done in accordance with NETA MTS (Maintnenance testing specifications), you don;t have to be a NETA company to test to the standards. Using a NETA company is typically a safer bet if you are not familiar with the ones in your area, but some NETA contractors are not that great and some that are not NETA are very good. You happen to live in an area with some of the very newest NETA members, of which I know little about, but I can say AET is a long standing member with some fantastic leadership. A respected company in NETA circles.

Now there needs to be some corrective action taken, is there a certification for some contractors who perform this type work ?

Maybe, depends on what it is. PEARL is an organization that writes standards and has members they qualify for reconditioning of transformers, breakers, etc.. But no real "certification" (Yet). I feel thier standards are not as stringent as they should be, and some members are not really focused on quality like they should be. For motors you would look for an EASA certified repair facility.

Basically you are going to get what you pay for, always ask for a scope of work to be provided, going with low bidders on these speciality type repairs to your power system can come back to haunt you.
 
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ATSman

ATSman
Location
San Francisco Bay Area
Occupation
Electrical Engineer/ Electrical Testing & Controls
70B is not very specific on tests, more of a guide. NETA is a recognized ANSI standard with specific tests and procedures, including specs on what is acceptable or not. The specs are based on other recognized standard for that specific equipment (IEEE, NEMA, etc..)

The whole point of using a NETA company with certified techs is that they are not associated with any manufacturer so it is a true independent 3rd party opinion of the condition of the equipment and recommendations should be unbiased. Using certified techs lets you know they are real testing guys (Tons of training and experience required to even take the exams, which are not easy to pass and proctored by an independent testing facility).

That said, a certified tech is well rounded but may not necessarily be an expert on a specific type of equipment. There are some really good NETA techs out there, and some average ones. There are also other companies that specialize in electrical testing with some very talented people that are not NETA certified (For example I used to be a NETA level IV tech, but no longer work for a NETA company, I did not forget everything when I left). Most testing guys not NETA now, were at one point.

A company does nto have to be an acredited NETA company to use the specs, I would recommend you always specifiy "tested per ANSI/NETA 2009 MTS" when looking for a contractor. IMO there is no better standard to follow, but some of the tests are optional so you need to specify exactly what you want done in some cases (PF tests for dry type transformers would be an example of an optional maintenence test you may want to consider requiring).

Very well stated, Zog:)
 

brian john

Senior Member
Location
Leesburg, VA
Many Specs simply state testing Per ANSI/NETA, this leaves the door open to minimal testing or the full blown testing per every option listed.

We have lost jobs as we try to cover all bases while other firms only bid the minimum.

In my opinion the specifying party should state exactly what they want. Not copy and paste off a 1984 specification (which I have seen).

If the work is worth doing then it is worth specifying what should be done.
 

ATSman

ATSman
Location
San Francisco Bay Area
Occupation
Electrical Engineer/ Electrical Testing & Controls
The Good, the Bad and the Ugly

The Good, the Bad and the Ugly

Very well stated, Zog:)

There are a lot of stories out there regarding T-shooting, repair, PM and testing of electrical equipment and the integrety of companies performing this work. Which brings me to this story.
I was hired by a large transfer switch (ATS) manufacturer to rewire one of their 1600A bypass isolation type (ZBTS160FC-7) ATSs that had recently burnt up at a hospital. The chief engineer reported that when they were performing their weekly generator test, they heard a loud BOOM when this ATS was transferring to emergency. The ATS was immediately isolated and LOTO (not a problem since it was a redundant chiller circuit.) This was one of the nastiest blowups that I have ever had to deal with. The main emergency solenoid as well as 80% of the wiring harnesses on the ATS power panel and in the bypass switch area were burnt and melted (by code, ATS wiring is not protected by fuses.) In performing the damage assesment inspection, I asked the chief where the platform was to roll out the ATS power panel (this model racks out horizontally.) He looked at me confused and said "we don't have a platform!" I looked at him and pointed to the inspection sticker on the door of the unit. The sticker was from another large ATS manufacturer (if not the largest, that we will call CO. X) and was dated the year before. I asked the chief how CO. X was performing the preventive maintenance PM) each year and he answered "they don't rack them out." I looked him in the eye and said " when I rack this out I will show you why it burnt up!" With the ATS racked out on a makeshift platform, I had the chief try to manually transfer the ATS with the handle (very hard to operate) and showed him the hard, dried grease in the mechanism gears at the back of the unit and said "this lack of cleaning and proper lubrication caused the unit to burn up." He looked at me with terror in his eyes and said "Oh my God, I have 6 more like this, can you give me a quote to PM them?"We repaired the unit, performed a complete PM and tested it to bring it up to proper operating condition.
We got the contract to PM and test the other 6 units successfully and, needless to say, left the site with a very happy customer.:grin:
Morals of the Story:
All switchgear companies are not created equal.
Just because it has a PM inspection sticker from a manufacturer doesn't mean the work was done correctly.;)

Tony
 

zog

Senior Member
Location
Charlotte, NC
Story of my life brother, a lot of these companies come in to PM switchgear and only do some basic tests and squirt some spray lube in the mechs (We call it technition in a can), which is actually worse than doing nothing at all, the spray lube displaces the real grease and makes everything work good for a few weeks but will lead to an eventual failure. (See link for a realted article) http://www.netaworld.org/files/neta-journals/NWsu07-Demaria.pdf

They usually only do basic tests and rarely check the many adjustments on every breaker that are critical to proper operation.
 

ATSman

ATSman
Location
San Francisco Bay Area
Occupation
Electrical Engineer/ Electrical Testing & Controls
Story of my life brother, a lot of these companies come in to PM switchgear and only do some basic tests and squirt some spray lube in the mechs (We call it technition in a can), which is actually worse than doing nothing at all, the spray lube displaces the real grease and makes everything work good for a few weeks but will lead to an eventual failure. (See link for a realted article) http://www.netaworld.org/files/neta-journals/NWsu07-Demaria.pdf

They usually only do basic tests and rarely check the many adjustments on every breaker that are critical to proper operation.

I agree with you on air frame circuit breakers which are more forgiving, but in the case of ATS mechanisms we find that after between 10 and 15 years without the proper maintenance, spray lube does not even displace the old grease no matter what that article states. We have to scrape the the old hard grease from the gears & cams (it becomes like hardened glue) with a screwdriver or putty knife to remove it to free up the transfer mechanism. Bottom line is the mechanism has to operate manually with a smooth action without binding before it can properly operate electrically to quickly cut out the solenoid coil from damage after it switches position.
 
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