Used Transformers: The Pros & Cons


To begin with, we should first understand why buying used transformers, unlike so many other types of reconditioned equipment, is a sound consideration. Not all equipment easily lends itself to being reconditioned by the nature of its design. This isn’t the case with most transformers.

Why Reconditioned Transformers are Practical

For a product to be economically practical for reconditioning, it must meet the following criteria:

  • Not be subject to rapid technological obsolescence.
  • Not be easily compromised by use.
  • The cost to rebuild must be significantly lower than the cost to build new.

Type of Reconditioned Electrical Equipment We Sell

  • Transformers – Dry Type | Three Phase
  • Circuit Breakers
  • Phase Converters

Brands of Used Transformers From Leading Manufacturers We Sell

  • ABB
  • Allen Bradley
  • Cutler-Hammer
  • Eaton
  • Federal Pacific
  • General Electric
  • Square D

Electrical transformers meet all three requirements!

Although manufacturing improvements have been made, basic transformer technology has remained the same since its invention. Relying upon simple electromagnetic induction to function, transformers have no moving parts to wear out over time due to mechanical stresses. This is the secret to the average 30-year expected lifespan with very little maintenance. Unless being completely rewound, transformers are relatively inexpensive to repair when compared to the cost of building new.

Having established that there is indeed an economic case of remanufactured transformers, we should now analyze the benefits and risks.

​The Benefits

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. Bruce Electric Equipment reconditioning lead times stand between 1 and 3 weeks. Additionally, the US has one of the oldest, and therefore most colloquial distribution 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

Remanufactured transformers tend to be between 10% and 40% lower cost than new ones. 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. This 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 greenhouse gasses. So go green, and buy reconditioned!

The Risks

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 Lifespan 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 way 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…

  • Provide ANSI C.57 test reports on the transformer once it has been rebuilt
  • Be willing to do witness testing/factory tours
  • Provide Dissolved Gas Analysis (DGA) results prior to rebuilding*
  • Has a formally documented reconditioning process
  • Provide at least a one-year warranty


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.

Bruce Electric Equipment 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, Bruce Electric Equipment has both new and reconditioned transformers for your project.