Power Transformers Blog – Expert Safety and Usage Info

MIDWEST frequently gets calls from someone wanting to sell used electrical equipment. We are very cautious of the biography of the equipment when the seller is someone other than the original owner. When there are any concerns, the equipment is shipped to MIDWEST, then thoroughly inspected and tested, before we consider purchasing. There are many concerns relating to the condition of used electrical equipment, so we may request pictures, prior use, nameplate data, and other details. Usually a visual inspection is the first line of rejection. With a little biographical information we can frequently determine that the equipment is scrap. As an example, we received a request to sell us three used 1000 kva 13,200 volt to 480/277 volt air cooled, dry type power transformers. The seller was not the company that had used the transformer and the condition was described as “In great condition.” He said he had the transformers for over two years and just wanted to sell them. We asked for pictures before shipping. We got the pictures and the transformers look great. No indications of structural damage. Paint condition indicated the transformers were probably used in a clean environment, a commercial building for example, rather than a manufacturing plant. But, the pictures showed the transformers stored outdoors. Outdoors in the rain and whatever might blow into the windings. Immediate rejection. The windings would be wet and contaminated. Because of the location, the moisture in the windings would have frozen in the winter. The steel structure would be rusted. And if they stored these transformers outside, they had little knowledge of the proper handling of 15 kv dry type general purpose transformers. The pictures said it all. Junk. 

The internet might be a great tool to find a replacement reconditioned or used 20 MVA transformer, fast. But the internet information could be deceptive and expensive. Nothing wrong or illegal, but it just might not be as good a deal as you think. Consider this example of what has happened to MIDWEST. A customer calls for a 25 MVA Transformer. Say a 138 Kv to 34.5 Kv, oil filled power transformer. And say our sell price is $300,000.00, plus freight. This should be a straight forward transaction.  And often these transactions happen fast, especially when someone has had a transformer fail. But, in this example, the buyer is a transformer ‘lister’ who marks up our price a whopping 30%.  A ‘lister’ is an entity that just lists equipment on their web site. They have no inventory themselves. They have limited technical value. They basically just have the information. This is not an indictment of all listers. Some are very good. But, in this case the ‘lister’ has been contacted by an electrical equipment dealer who also does not stock large equipment, much less large transformers. The dealer marks up the lister’s price a whopping 30% also, because he thinks the buyer just has to have the transformer. The dealer has been contacted by an electrical contractor, who also thinks he can mark it up 30%, because his customer, the actual end purchaser and user of the transformer, just has to have it. The problem is, by the time the shark’s get done marking up the price, the cost has doubled to over $650,000.00 and the end user knows they can buy a brand new unit for much less than $400,000.00.  They feel taken, so they decide to cripple along until they get a brand new transformer. 

This same scenario can happen with high and low voltage switchgear, circuit breakers, and any number of other type electrical equipment.  So how can you tell if you are talking to an intermediary or directly to the source of the equipment? The best bet is to be talking to someone who knows the equipment. Is an expert on the equipment you want to purchase.  Can give you detailed additional information immediately rather than making you wait two hours for answers to each question. Deal with the experts.

What do you do if your manufacturing company suddenly loses its main 5000 kva, 34.5 kv to 480 volt transformer? You have orders pending. And if you can’t fill them, a key account may go elsewhere. You have employees suddenly out of work.  You need to heat the buildings.  And you are told it will take 10 weeks to get a new replacement transformer. This is one of a manufacturer’s worse nightmares. What to do? This happens more frequently than one may realize. MIDWEST actually recommends a “Disaster Action Plan,” on the shelf, ready to go, in case of such a nightmare.

MIDWEST receives these calls all too frequently. You might be fortunate and MIDWEST have a replacement reconditioned or used 5000 kva transformer that can be shipped immediately. No one has new transformers this size in stock. And many companies will not accept anything but a new replacement power transformer. In that case, the best solution is to rent a temporary transformer that will provide power until a new replacement transformer can be specified and manufactured. A new replacement transformer may take 10 weeks.

Renting transformers, and other electrical equipment, is a common solution to this critical problem. The first big question to ask when such an emergency occurs is, “Do you want power back on permanently as quickly as possible or do you just want power back on as quickly as possible?”  There is a huge difference in the time to perform either of these solutions. And way too often there is the presumption that one just must get power back on permanently. This presumption continues until the customer realizes how long it will actually take. Meanwhile many hours, even days, are wasted by chasing the wrong solution.

So the most critical event is to decide how fast one wants power restored.  MIDWEST has transformers, temporary high voltage cables and low voltage cables, and switches in stock.  But, more important, is the knowledge that temporary power installations can be a life saver for a facility that is suddenly down.

MIDWEST was asked what we did with perfectly good obsolete or old used transformers. Bit of an oxymoron since obsolete might be understood to mean no longer any good. But the intent of the question was obvious. Transformers that are too old to be sold in the used transformer market might be maintained in MIDWEST’s pool of rental, temporary, and emergency transformers or they are just scrapped. Typically a rental transformer is just for temporary use. But we have had many transformers on rental for over a year. Especially larger Mva transformers. We have a few we didn’t scrap out but kept around solely because of the special voltages or size or physical configuration, to be used in those rare occasions when a manufacturing company, for example, is in trouble with delivery of a special replacement transformer. This usually happens when they had a non typical transformer suddenly fail. The difference between these special temporary transformers, which we sometimes call cling-ons, and our rental transformers is that we’d really like to get rid of the cling-ons. But about every time we think we’ll scrap out an obsolete old unit, we get a desperate call and it is the only thing that will work and the only one the customer can find. So it is resuscitated again and lives on. We do have fewer of these than ten years ago. We just scrapped out a 2000 Kva oil filled power transformer, 13,200 volts to a variable secondary of 120 volts to 600 volts. Weighed 18,000 pounds. A big old power transformer, specially built for a transformer power lab about 60 years ago. We finally got rid of it because we never rented it in two decades; And we did not have a good biography on the unit, although all our test results were good. The install cost as a rental, emergency, or temporary transformer would have been potentially huge because of the oversize and weight due to the many voltage taps. A potential customer would only need one functional voltage and would be paying a premium for a monster oil filled power transformer when they probably could find a unit with their specific voltage. Plus MIDWEST can not rent a transformer we no longer have full confidence in, even during an emergency. In the last month we designated over ten transformers to the scrap heap. Mainly because of a lack of full confidence in their reliability, even though many of them had good test results. MIDWEST knows electrical tests, on used oil filled and dry type power transformers, are not a perfect indication of the condition of the transformers. So MIDWEST looks for reasons to get rid of the old and the cling-ons.

10.       Even if they don’t know the song, used transformers hum along as if they did.

9.         Used transformers require no burn in period. They are good to put in service right out of the crate. 

8.         Used transformers are very green. The carbon footprint you save may very well be your own.

7.         Buying used transformers helps create jobs.  With the money saved, your company will have more resources to put into that next great business expansion.

6.         Buying used transformers puts you in the drivers seat ─ of your golf cart that is. As your boss will no doubt give you the afternoon off after saving the company money.

5.         Our used transformers meet national testing standards.

4.         Our used transformers are readily available. Lead times for new transformers can run into weeks if not months. Your used transformer can be in your hands as soon as preparation time allows. 

3.         Our used transformers come in designer colors. Check out our beautiful array of designer gray colors.

2.         You may choose to rent one of our used transformers to serve as a temporary power solution.

1.         And the number one reason to buy used transformers is it saves money, up to 70% off the cost of new.