This article is primarily discussing medium voltage, oil-filled distribution transformers, but the same logic can be applied to most other types of transformers as well.
To begin with, we should first understand why buying a reconditioned transformer, unlike so many other types of reconditioned equipment, is a sound consideration. Not all equipment easily lends itself to being reconditioned by nature of its design. This isn’t the case with most transformers.
Why Transformer Reconditioning Is Practical
For a product to be economically practical for reconditioning, it must meet the following criteria:
Transformers meet all three requirements!
Having established that there is indeed an economic case of reconditioned transformers, we should now analyze the benefits and risks.
1) Speed Of Delivery
New transformer manufacturing lead-times in the US stand between 10 and 30 weeks depending on market conditions. This time frame is simply not an option for many projects, especially emergency replacement situations. Maddox reconditioning lead-times stand between 1 and 3 weeks. Additionally, the US has one of the oldest, and therefore most colloquial distributions systems, meaning that dozens of different distribution voltages exist. This lack of standardization means that almost every single transformer is still engineered-to-order to this day. The cost to maintain a sufficient inventory is far outside the scope of most electrical distributors. This creates an opportunity for rebuilders to maintain an inventory with a broad range of voltages to fill needs as they arise.
2) Lower Cost
Reconditioned transformers tend to be between 10% and 40% lower cost than new. But what about power cost savings with new, more efficient designs? While slight efficiency gains have been made in transformer design (around 1-2% as of DOE 2016) the savings in power bills from the utility will never offset the added upfront cost for a new transformer.
3) Lower Risk Of Failure
The vast majority of transformer failures happen immediately upon energization. Relatively few failures occur between year 3 and year 30 of service. Which means that if a transformer has been successfully been energized, served for a time, and then removed from service with no issues, the secondary buyer of such a unit has the added insurance of getting a transformer that has truly been proven in the field.
4) Lower Environmental Impact
Some propose that newer, more efficient transformers are more environmentally friendly due to lower losses. However, the slight efficiency gains made in recent years will never offset the environmental impact of manufacturing a new transformer. According to the EPA, manufacturing produces 5 percent of total U.S. greenhouse gas emissions. The rebuilding process produces almost no green house gasses. So go green, and buy reconditioned!
1) Issues Created By Low-quality Rebuilders
The transformer may have been taken out of service with no issues, but a low quality rebuilder may have introduced an issue not previously present through poor workmanship.
2) Shortened Life-span Due To Unknown History
A previous owner may have gotten rid of the transformer because of some known issue.
Minimizing The Risks
A quality rebuilder can easily offset these considerable risks. This why it’s key that you qualify not just the product but also the rebuilder. Before buying any reconditioned transformer, make sure that the company producing the transformer can, at a minimum...
Transformer reconditioning has been a niche industry nearly since the invention of the technology. Buying a reconditioned transformer is often an excellent option when needing to make project deadlines and budgets. New is not necessarily better than reconditioned, but you should always do your due diligence, and qualify the rebuilder to ensure you are getting a quality product.
Maddox Industrial Transformer specializes in new and reconditioned 3-phase transformers, keeping thousands in stock at all times. Contact us today to see how we can help you! Whatever your needs, Maddox has both new and recondition solutions for your project.
*More About DGA Results
The oil inside a transformer acts as an electrical insulator, and as a cooling medium. But it also gives us an excellent diagnostic tool. Any internal issue with the transformer (such as arcing, or overheating) changes the chemical makeup of the fluid, and produces combustible gasses. These gasses are easily tested for via DGA testing. This testing gives you an idea of the unit’s history. If some gasses do show up, the rebuilder should be able to explain why they are present, and what they intend to do to fix the issue that caused the gassing in the first place. Transformers that have been “run hard” by over-heating, or over-loading often have some gas build-up caused by insulation paper breakdown. It is important to know the condition of the transformer prior to rebuilding to make a determination. Some low-quality rebuilders will simply replace the oil with new in an attempt to erase the evidence of abuse.