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AD 40 HP – 40 HP Digital Phase Converter

$5,553.00

The AD 40 HP Rotary Phase Converter delivers digitally controlled 3-phase power from single-phase service for demanding, voltage-sensitive applications.

Built for CNC systems, welders, and precision machinery, it provides stable, balanced output.

Featuring the MicroSmart™ Controller and a custom GENTEC Baldor VIT™ generator for reliable, long-term performance.

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Built and Supported in Wisconsin, USA

Lifetime Warranty

Same-Day Replacement

General Specifications

Model

40

Efficiency

>98% (at Power Factor of .9)

Idle Power Consumption (kW)

1.20 ($0.12/hr)

Single Phase Requirements

Input Voltage
208 – 250
Frequency (Hz)
50 / 60
Minimum Wire Size

1

Minimum Breaker Size

125

Three Phase Specifications

Voltage Balance
0 – 5%
Maximum Starting Load

20 HP / 56 amps

Maximum Running Load

40 HP / 112 amps

Physical Specifications

Idler Insulation Class
F
Idler RPM
1750
Idler L × D × H

22.5” × 21” × 16”

Panel H × W × D

24” × 18” × 8”

Panel Style
NEMA 1 / Type 1 Indoor
Total Weight (lbs)

368

Refer to the installation guide and full specification sheets above for complete wiring, dimensional, and electrical details. Proper sizing and installation ensure safe, reliable operation.

AD Series Technology

The AD Series is engineered to provide optimum performance for voltage-sensitive applications through American Rotary’s proprietary digital phase conversion design. Built for precision equipment, it delivers stable voltage, true sinewaves, and adaptive load control.

MicroSmart™ Controller

Our proprietary digital controller monitors output voltage every 50 milliseconds, providing precise voltage balance and adapting to changing loads. This protects CNC machines, welders, and other sensitive equipment from nuisance tripping and voltage fluctuation.

GENTEC Baldor VIT™ Generator

Designed specifically for phase conversion, the Variable Impedance Technology (VIT™) generator provides a true soft start with reduced starting current. This minimizes voltage drop and protects your valuable equipment.

Stable Voltage and True Sinewaves

By balancing power factor and phase angle, the VIT™ induction generator produces clean, undistorted sinewaves for cooler operation, improved efficiency, and longer equipment life.

Expandable Design & Full Current Starter

Custom-designed starter components handle demanding loads, while expandable options and upgrade paths allow the AD Series to grow with your shop needs.

Explore full AD Series technology →

American Rotary backs our phase converters with an industry-leading warranty, including Lifetime Warranty coverage on our AR, AD, ADX, AI, and AMP Smart Series models.

All control panels are warranted against defects in workmanship and materials, with service available in the field or at our Factory Service Center in West Bend, Wisconsin.

Complete warranty details are available here: https://www.americanrotary.com/warranty/

See the AD Series in Action

The AD Series is built for voltage-sensitive equipment requiring precision power. Watch how the MicroSmart™ Controller monitors voltage in real time to maintain balanced output and adapt to changing loads.

From CNC machines to welders and rectified loads, AD converters provide digitally controlled 3-phase power to protect equipment and reduce nuisance tripping.

Our Advantages

Why Choose American Rotary
Phase Converters

Same-Day Shipping

Converters are built, tested, and stocked in our Wisconsin facility, then shipped the same day. You get the power you need without waiting weeks.

Proprietary Technology

Custom Baldor generator, digital MicroSmart™ control, CTR™ stabilization, and surge protection — technology you’ll only find at American Rotary.

Lifetime Warranty

Every converter is backed for life. You know we will support the unit as long as you own it.

Same-Day Replacement

If something does go wrong, we do not leave you stuck. We ship a replacement converter the same day so you can get back up and running.

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Customer stories

Real experiences from people who trust our products

My old rotary phase converter gave 30 years of faithful service before it went up in smoke. With customers asking when I’d be operational, I researched every manufacturer and the choice was clear on American Rotary. First impression when it ... READ MORE

FAA Certified Machine Shop Owner

  • Machining

Very good company to do business with. The salesman Lenny treated me like I was a big company. I was shopping for a roto phase for my home machine shop. He had all the time in the world for me. ... READ MORE

Rodney Mears

  • Machining

A quick google search pointed me toward American Rotary. It wasn’t their website or their pricing but the number of videos and testimonials about the quality of their product and the great service. I wasn’t disappointed. I called on a ... READ MORE

Carl DiPaolo

  • Machining

I purchased this unit for a tenant in a commercial property that needed 3 phase power and the cost for the utility company to bring it in was significantly higher with much longer times to complete the project. The phase ... READ MORE

Matt Peace

  • Metalworking

I tried an inexpensive digital converter that made my machine motors very hot due to unbalanced power. A person I bought a milling machine from said he had an American Rotary and was very happy with the quality, so I ... READ MORE

Brad Everett

  • Machining

When I started, the garage had a single 120 V receptacle behind a shelf. Now, there (4) duplex 120A receptacles, (1) NEMA 16,20 A 240/120V with a DPDT switch to select voltages. 30A 50A 1 phase receptacles. Two 20A, one ... READ MORE

Raymond Jensen

  • Agriculture

I called in a talked to a representative told them I have a refrigeration unit I was looking to run 3 phase to, gave them the specs and was recommended the ADX 10. I ordered it super fast shipping got ... READ MORE

Jonathan Arrington

  • Food Service

I had to move my workshop due to rent increases. The one I found didn’t have 3 phase. I found some cheap crappy digital shifter…didn’t work. Then I found American Rotary, they are the real deal! I am able to ... READ MORE

Mike Chinn

  • Woodworking

para todos los hispanohablantes America Rotary 100% recomendado fácil de instalar fácil de manejar fácil de cablear todo perfectamente gracias por su ayuda para poner en funcionamiento mi máquina edgebanding 3 Phase For all Spanish speakers, American Rotary 100% recommended. ... READ MORE

Neftaly Bustos Custom

  • Woodworking

Just got my ADX 5 up and running couldn’t be happier with my decision to purchase this excellent customer service and tech support. A++++++

... READ MORE

Mark Anderson

  • Metalworking

Absolutely love what american rotary does. Had a wonderful experience with their support team the phase converter we purchased and the transformer were supper easy to install definitely recommend buying from them. Customer service is 10/10

... READ MORE

Custom Machined Concepts | Andrey Girenko

  • Machining

American Rotary is an awesome company to work with, Mike was/is very helpful in answering my questions and getting me what I needed to get my shop ready for a new machine, giving me an option to either piggy back ... READ MORE

Charles Nelson

  • Machining

FAQs

Everything you need to know about getting the right power for your equipment.

Read all FAQs
How do I know which phase converter I need?
Choosing the right size depends on your equipment s full-load amps and how many machines you ll run. Use our Sizing Tool or talk with an engineer. We ll make sure you get the right match.
We stock and ship converters the same day from our Wisconsin facility. No long wait times. Most customers are running in just a day or two.
Yes. Our converters use proprietary technology like a custom Baldor generator, MicroSmart control, CTR stabilization, and built-in surge protection to deliver clean, stable power under load.
Same-day shipping, proprietary power technology, lifetime warranty coverage, and same-day replacement. No other company combines all four.
We don t leave you waiting. If theres an issue, we offer same-day replacement and lifetime support from engineers who know your equipment.
Most customers have an electrician handle the final hook-up, but our converters come pre-tested and include clear install guides and videos to make setup simple.