Electrical Maintenance program

[kevinware]

Merry Christmas all,

Please allow me to ask the opinion of this form. I presently work in an information technology environment, we are not classified as an "Information Equipment Room" as far as 645.4 goes but the room is full of computer equipment, somewhere around 40 server racks and around 250 servers. My goal is to implement an electrical maintenance program for the electrical system that supplies this room and the rest of the building. A few months ago we had a situation where we lost three sub-panels that were daisy changed from one 100 amp breaker, but that is another story. I believe that if an electrical maintenance program was in place then this incident could have been prevented. We presently have seven 225 amp panels that line the back wall of the equipment room and we are in the process of moving all loads from these panels to four 150KVA PDU's. There was never a maintenance program for this area and I will be starting from scratch. What kind of things should I incorporate into the development of this plan? Where could I find information, books, web sites?

Thanks to all,

Kevin

 

[bphgravity]

Re: Electrical Maintenance program

Have you reviewed the NFPA 70B by chance?

 

[charlie tuna]

Re: Electrical Maintenance program

kevin,
with that amount of equipment i would suggest you consider an electrical infrared scan. this scan performed by a qualified person can tell you alot about your present system condition. it can indicate not only loose connections but also unbalanced loading, failing circuit breakers, and overloaded circuits. again, the thermographer must understand electricity and what you are looking for. this scan can point out the troubled areas and then you can take appropriate action to fix the problem. if there are a large number of problems found, you should consider a yearly scan until everything is weeded out! again, tell the infrared operator you are looking for a full discription of each section of your installation -- with a full report.

 

[catchtwentytwo]

Re: Electrical Maintenance program

Try your company's insurance company, they usually have a relationship with a thermography firm.

 

[charlie tuna]

Re: Electrical Maintenance program

i have recently retired and could not find a qualified company to take over my accounts. the advantage of an electrician doing the scanning, is because he understands load,unbalanced load,heavy loads on neutrals etc.. remember, you don't want to start looking for a problem when it doesn't exist!! an example might be:

on one of your panels he records a 10 degree temperature rise inside the main feeder breaker on "B" phase. he would then use an ampprobe to measure the amperage at that time. lets say his measurements are:
A phase-----70 amps
B phase-----120 amps
C phase-----75 amps

he could understand the addition heat on this phase since it is drawing 55 more amps of load than the other two phases.
but he would write this up as an unbalanced load in his report so that any additional loads placed on this panel be connected to A or C phases.

or say he notices a small amount of heat on the main neutral terminal. this is not normal. again, he ampprobes it and finds you have the beginning of some harmonic problems.

without the electrical background -- along with the infrared expieriance most electrical scans will not help you---my oppinion only! if you find the right guy -- you will know whats happening inside your distribution system and if you have room for expansion and in which panel. you will know that you have a main breaker going bad or a branch circuit breaker going bad, plus that all your connections are tight!

 

[catchtwentytwo]

Re: Electrical Maintenance program

We had a problem when an electrical contractor did the scan on a weekend and didn't get the "report" done until Wednesday. During the scan he didn't mention the problem he found. Worse part of this is they were also the installer. Talk about a "fox in the henhouse"!

I've found it best to hire both a good non-electrical contractor thermographic firm and have qualified electricians work with him. They can remove/reinstall panel covers and trims, working ahead of the scanner. That speeds the work and you have someone to do repairs while the scan continues. And you get the benefits that Charlie mentioned with a second opinion present.

 

[charlie tuna]

Re: Electrical Maintenance program

never allow any scanning unless it's during peak hours---a weekend is usless! how long it takes to get the report is a function of the size of the building and the work load of the thermographer and his office staff! we usually begin our scans at 8:00 am and start in the elevator machine room --- this is normally a busy time for office towers. we never want anything less than full load conditions. we used the inframetrics 577L camera which is an old one, but extreamly sensitive --requires liquid nitrogen to work and is heavy and a pain to move around. but i could find a problem inside a panel with the covers "on" that other cameras couldn't find with the covers "off"! over the years i found buildings continue to reduce their electrical problems from eighty down to a handful! sometimes they would have us do the recommended repairs and sometimes they would do them "in house".. we never advertised our infrared services -- only to our customer base ---yes we scanned some of our own installs --- didn't make a difference to us. and infrared isn't foolproof. we have had stuff blow up after we scanned it ---stuff goes bad, it happens! but we have also warned customers about problems that they ignored -- and it blew up!!!!!

 

[rick hart]

Re: Electrical Maintenance program

What kind of things should I incorporate into the development of this plan? Where could I find information, books, web sites

WWW.netaworld.org is a great place to start; NETA sets the standards for electrical maintenance and testing.

Thermal scan is a place to start and get a feel of the overall condition of things as they are. There are safety concerns when opening fully loaded electrical equipment that require the appropriate PPE, so be advised OSHA lurks.
However, with this situation, it sounds like you are looking for a more in depth approach that can be trended and documented. This sort of testing is usually beyond the capabilities of most maintenance personnel but, anyone can be trained.
Digital Low Voltage Resistance measurements of connections and contacts, Turn Test Ratio for transformers (at least once after they are installed), megohm testing of conductors plus a good cleaning on a scheduled (annual) basis are Things that will help you get ahead of failures. When completed, attach a sticker with the date and due date; some items do not require annual but every three years is acceptable. NETA has a matrix to assist in setting maintenance intervals along with prescribed intervals.
List all of your equipment on a spread sheet that you find critical and keep track of when the maintenance is performed. Update the spreadsheet during the next cycle with the current date. Note any defeciencies and needed corrections that need imemdiate correction or can wait until the next maintenance shutdown.

If you have liquid filled transformers, a dissolved gas analysis is indispensable.

 

[charlie tuna]

Re: Electrical Maintenance program

rick,
that sounds good. many of the top maintained high rise office buildings we service hire us to infrared yearly and contract us to perform a complete main switchgear shutdown and cleaning and inspection/ and tested every seven years. the power source(s) feeding the original poster's "I.T." panels should be included in his maintainance program..

 

[BruceH]

Re: Electrical Maintenance program

Charlie Tuna, would it be out of line to inquire on the pricing associated with the infrared scan service you performed. I understand the equipment is expensive and imagine this would take some time to recoup. How did you market this service? Yourself, salesmen?

 

[charlie tuna]

Re: Electrical Maintenance program

bruce,
i am retired now after 25 years in business in the south florida area. the "nitch" type of electrical work we did was high rise office buildouts which exposed us to alot of work for the building owners. after fifteen years of working for general contractors on the buildouts and also performing more and more work for building owners, i decided to stop all work for general contractors and work only for building owners --- less headaches and no problem getting payed. in 1989 we were contracted by one building to perform yearly testing and infrared was part of the requirement. after alot of trouble of even getting information and the independence of the available infrared people led me to invest in my own equipment --which was very expensive ---about $38k at the time. i never marketed this thermography to other than my present customers -- word of mouth was enough to keep us as busy as we wanted in the infrared end. this was not a good business decision -- because the payback was slow. but it was what i wanted and we had a obligation to keep our present customers happy with their electrical needs. it was a very interesting investment and it payed off for us and our customers. another thing was variable speed drives. we got into them early and converted many of our customer's equipment to provide more efficency and dependability to their operation. also data recorders and metering!!! you see all these little facits keep you locked to your customer base and you stay busy reguardless of the ecconimy. it was a real nice ride(25 years) --happy customers make for a happy work enviroment.
sad thing is i tried to turn over these accounts to some other infrared contractor and i can't find one that knows what they are looking at!!! i have nobody to recommend!!!!!!!!!!!!!!!

 

[BruceH]

Re: Electrical Maintenance program

Thanks for the reply Charlie. I've been reading of this technology for some time and understand that it certainly does take an experienced and intelligent individual to accurately decipher the results of the scan and recommend appropriate action if any. Many are just seeking easy, black and white answers and are not inclined to really be a professional in their field, too bad. Sounds like your customer base and equipment would be worth a great deal to a knowledgable contractor in your area.

 

[ron]

Re: Electrical Maintenance program

A great place to start IMHO, is to be sure you have an accurate one-line diagram of the facility. Then update (or perform for the first time), a short circuit and coordination study. Then followed by an arc flash hazard analysis, as you probably do energized work.
Then an infrared scan, and performance of NETA or manufacturer recommended maintenance to all equipment.

 

[petersonra]

Re: Electrical Maintenance program

Make sure you have reliable drawings as another poster said. If there are none, make some. Sketches are better than nothing. It is important to physically verify that the drawings you have are accurate too. Often over time modifications are made and the drawings not updated.

Once you have a reliable set of drawings, review them carefully. Go through your equipment (both distribution and loads) and make notes on your drawing set as to what is actually there. Make sure you have not overloaded any of your panelboards and that the branch circuits are adequately sized.

 

[dave_asdf]

Re: Electrical Maintenance program

if you have any back-up power equipment you should be testing that also. generator - monthly run unloaded for 10 minutes, every 6 months loaded; ups batteries or dc plant batteries should be tested every 6 months and replaced every 4 years or so. make sure your ats switches (util fail test). your ups is no good if you have 1 open battery and your generator is no good if your ats wont switch.

 

[rick hart]

Re: Electrical Maintenance program

if you have any back-up power equipment you should be testing that also. generator - monthly run unloaded for 10 minutes, every 6 months loaded; ...

I really need to jump in here-

IF the standby power supply is a diesel engine, do not run it unloaded for any length of time. You can really foul up the engine because the temperature can not rise enough to burn the crud (wetstacking) that accumulates in all diesels. Hospitals are required to run their generators a minimum of 30 minutes every month at no less than 30% of the nameplate. Some even test weekly and transfer all load available. That tests the transfer switches, engines, UPS (they have to ride through the transfer). If we are talking critical loads, an annual check of the ATS that includes timing functions along with the DLRO test of the contacts are in order.

 

[catchtwentytwo]

Re: Electrical Maintenance program

Eventually you need to do a "utility failure test" to see if all your systems work. Look at UPS not accepting power from new generator .

Before you consider that, do a battery PM with a firm that specializes in batteries, preferably not a UPS maintainer. He can determine how much redundancy is available....especially important if a bad jar needs to be "jumped out". You also need an idea of how often (and the duration of) power hits that use the batteries.

This is extremely important if you have VRLA batteries, more so if they are more than a couple of years old, have no documented maintenance history (IEEE 450, IEEE 1188) or have any cells jumped out. The battery manufacturer can determine the age based on the unique date code (serial number) on each jar. If you find any cells that are questionable, at minimum, replace the questionable ones but be aware that you'll probably need to plan to replace them all.

Don't "pull the plug" until you find out if the manufacturer has replacements available on a emergency basis. Their production runs are order-based and you need to know how long you might have to wait.

[ January 04, 2006, 07:53 AM: Message edited by: catchtwentytwo ]

 

[dave_asdf]

Re: Electrical Maintenance program

"quote"

I really need to jump in here-

IF the standby power supply is a diesel engine, do not run it unloaded for any length of time. You can really foul up the engine because the temperature can not rise enough to burn the crud (wetstacking) that accumulates in all diesels.

i cut and pasted, i've got no clue how to do the quote thing.

i strongly recommend running the diesel engine monthly. i run my generator every month for 10 minutes, ever 3 loaded at about 20% (all the load i have) for an hour and every 2 years at full load for 4 hours. Carbon buildup is a small price to pay to prevent condensate buildup in the generator and exhaust manifold.

 

[zog]

Re: Electrical Maintenance program

The NETA frequency of maintenance tests is a free download at www.netaworld.org.

Also NETA is having its annual conference in Memphis in March, there is alot of valuable information to be had regarding Electrical PM programs, infared, etc....

 

[rick hart]

Re: Electrical Maintenance program

Also NETA is having its annual conference in Memphis in March, there is alot of valuable information to be had regarding Electrical PM programs, infared, etc....

I went to the Dallas conference a few years back and walked away understanding more things than I ever thought were out there. If anyone interested in starting a comprehensive maintenance program can make one of these, they will be well served.

Besides, NETA really knows how to throw a party.