Substation Transformer

These heavy duty transformers are ideal for substation yards and power distribution line-ups.

Maddox substation electrical transformer

Capabilities

Maddox’s liquid-filled distribution substation, and power-class substation transformers are designed, built, and tested in accordance with the highest industry standards including NEMA, ANSI C.57, DOE, and IEEE as applicable. With a range of customizable features, Maddox substations can be configured to maximize performance, minimize potential arc flash exposure, and address environmental concerns. All designs can be supplied with full, or partial length air terminal chambers to make installation easy.

Product Scope

kVA range: 300 kVA - 25,000 kVA base
Voltage range: Up to 69,000v

Technical Specs

Technical illustration of standard substation transformer

Standard specs

Type II non-PCB mineral oil (ONAN)
High-grade silicon-steel core
Aluminum windings (distribution class)
On-load tap changer
Reinforced carbon steel tank
Lifting lugs
Externally clamped high- and low-voltage bushings
Pressure relief valve
Pressure vacuum gauge
Liquid temp gauge
Liquid level gauge
Drain and sample valve
Schrader valve
Ground pads/lugs
Nitrogen blanket
65 degree C rise

Optional upgrades

Environmentally friendly, high fire-point FR3 oil (KNAN)
Copper windings
On-load tap changer
Stainless steel tank
Gauges with contacts
Auxiliary control cabinet
Winding temperature indicator
Fan package (ONAN/ONAF)
Lid-mounted pressure relief device
Sudden pressure relay
Lightning arresters
55/65 degree C rise
Step-up solar and wind duty design
Electrostatic shielding
K-rated design
Primary load-interrupter switch

Get Started

We make it easy to get a quote and order a transformer. Follow the steps below to get started

Request a Quote

Call or fill out the form below to get a quote. Most quotes are turned around the same or next-day.

Place your order

Send us a purchase order, or give us a credit card number, and your dedicated customer service rep will send you an order confirmation and answer any questions you may have.

Receive your transformer

We’ll handle all transportation and logistics. Maddox has the shortest lead times in the industry so you can get the power on when you need it.

"Over the last couple weeks Maddox responded quickly to our customers needs. They provided two transformers on a short time table allowing us to get our customer re-energized. One transformer was in stock, and shipped immediately. The second had to be reconditioned and they turned it around and shipped in just a few business days. Great service with good communication along the way."

Brian Rodgers, NETA level III tech

"My company ordered a new transformer from Maddox. Kurt was an AMAZING sales rep that listened to all my concerns and met them all with solutions that fit our timeline. Dale pulled off a miracle in getting our shipment on the road and delivered not only at the exact time I requested, but 2 hours early. I cannot express how happy I am with this company. They made me look like a hero! Which is exactly what THEY were to me."

Jen Glab, microgrid sales

"We ordered transformers to use for our industrial equipment applications due to market shortages for our standard stepdown transformers. Delivery was incredibly quick and products look and operate without issue. Priced very well in comparison to other outlets - very happy to utilize Maddox in the future for our continued needs."

Todd Griffieth, ops manager

"I have purchased dozens of Maddox transformers, both low voltage dry-types and large reconditioned medium voltage units. Always great service and quality builds, with faster than industry standard lead-times."

Eric Raybould, distributor

"Quick delivery with helpful friendly staff. Great service and highly recommended. A great company to work with on all your transformer needs."

Austin Spiegel, project manager

"Over the last couple weeks Maddox responded quickly to our customers needs. They provided two transformers on a short time table allowing us to get our customer re-energized. One transformer was in stock, and shipped immediately. The second had to be reconditioned and they turned it around and shipped in just a few business days. Great service with good communication along the way."

Brian Rodgers, NETA level III tech

"My company ordered a new transformer from Maddox. Kurt was an AMAZING sales rep that listened to all my concerns and met them all with solutions that fit our timeline. Dale pulled off a miracle in getting our shipment on the road and delivered not only at the exact time I requested, but 2 hours early. I cannot express how happy I am with this company. They made me look like a hero! Which is exactly what THEY were to me."

Jen Glab, microgrid sales

"Over the last couple weeks Maddox responded quickly to our customers needs. They provided two transformers on a short time table allowing us to get our customer re-energized. One transformer was in stock, and shipped immediately. The second had to be reconditioned and they turned it around and shipped in just a few business days. Great service with good communication along the way."

Brian Rodgers, NETA level III tech

"My company ordered a new transformer from Maddox. Kurt was an AMAZING sales rep that listened to all my concerns and met them all with solutions that fit our timeline. Dale pulled off a miracle in getting our shipment on the road and delivered not only at the exact time I requested, but 2 hours early. I cannot express how happy I am with this company. They made me look like a hero! Which is exactly what THEY were to me."

Jen Glab, microgrid sales

Get A Quote

Maddox substation transformer ready to ship out