Technical Support
Rotary Phase Converters: Single Phase to True Three Phase
American-made rotary phase converters, 3–200 HP: true, balanced three-phase power from single-phase service for CNC machines, compressors and whole shops. Lifetime warranty. Free sizing: 800-417-6568.
Read more: how they work, sizing, NL vs PL vs DualZone & FAQ
How a rotary phase converter works
A rotary phase converter turns the single-phase power you already have into true three-phase power. A heavy idler motor (the generator) spins up on your single-phase supply and generates the third leg. The result is balanced three-phase power on all three legs, so your machines run at full rated horsepower. That's why rotary converters run CNC machines, compressors, HVAC, welders and whole machine shops where a static converter or a VFD can't.
Sizing a rotary phase converter by horsepower
Start with your largest motor. For standard loads, pick a converter about twice the horsepower of that motor. A GP10NL, for example, runs 10 HP in total and starts a single motor up to 5 HP. For hard-starting loads such as compressors, HVAC and high-inertia equipment, start at 2.5 times the largest motor. Running several machines at once? Add up everything that runs at the same time. Not sure? Call 800-417-6568 for free sizing from a phase-conversion specialist, not a call center.
NL, PL or DualZone?
- NL (Standard): the workhorse. Reliable three-phase power for shops and CNC, 3–100 HP.
- PL (Premium): adds magnetic starter controls (start/stop) and voltage-monitor protection.
- DualZone (Auto-Zoned): two precision-balanced idler motors that start one after the other to soften the starting surge. More generating capacity than a single-idler unit of the same rating, for big shops and multi-machine loads, 10/20 to 100/200 HP.
Built in the USA since 1968
Every Phoenix rotary phase converter is assembled and tested in Phoenix, Arizona. Each one has a TEFC cast-iron idler motor and a NEMA 4 indoor/outdoor enclosure as standard, a lifetime generator warranty, and full wiring diagrams. Most units ship in 1–2 business days from U.S. warehouses.
Rotary phase converter FAQ
What is a rotary phase converter?
A machine that uses a spinning idler motor to turn single-phase power into true, balanced three-phase power, so three-phase equipment runs at full rated horsepower.
What size rotary phase converter do I need?
For standard loads, about twice the HP of your largest motor. For compressors, HVAC and other hard-starting loads, about 2.5 times. Call 800-417-6568 for free sizing.
Rotary vs. static vs. VFD: which is better?
A static converter only helps a motor start, then runs it on single phase at about two-thirds of its power. A VFD runs one motor. A rotary converter makes real three-phase power for several machines, including CNC.
Can a rotary phase converter run a CNC machine?
Yes. Balanced output on all three legs is what CNC controls and drives need. We size for the whole machine, not just the spindle.
What's the difference between NL, PL and DualZone?
NL is the standard model. PL adds magnetic starter controls and voltage-monitor protection. DualZone uses two idler motors for more capacity and a softer start on large loads.
Where are Phoenix rotary phase converters made?
Assembled and tested in Phoenix, Arizona, with a lifetime generator warranty.
100 HP Rotary Phase Converter GP100PL - Single Phase to Three Phase Converter
$14,780.00The GP100PL rotary phase converter delivers 100 HP of continuous three-phase power from a standard single-phase 230V supply — with a built-in LED monitoring panel for real-time power status at...
60/120 HP ROTARY PHASE CONVERTER - GP60/120NL Auto-Zoned Power Rotary Phase Converter
$16,480.00The GP60/120NL DualZone rotary phase converter pairs two 60 HP idler motors to deliver a full 40 HP of continuous three-phase power — with more combined core steel and copper...
75/150 HP ROTARY PHASE CONVERTER - GP75/150NL Auto-Zoned Power Rotary Phase Converter
$22,700.00The GP75/150NL DualZone rotary phase converter pairs two 75 HP idler motors to deliver a full 40 HP of continuous three-phase power — with more combined core steel and copper...
100/200 HP ROTARY PHASE CONVERTER - GP100/200NL Auto-Zoned Power Rotary Phase Converter
$29,340.00The GP100/200NL DualZone rotary phase converter pairs two 100 HP idler motors to deliver a full 40 HP of continuous three-phase power — with more combined core steel and copper...
Shop Rotary Phase Converters by Horsepower
Pick the HP rating that matches your largest single motor. Each page compares every Phoenix model in that size — Standard, Premium, AutoStart, AutoLink — side-by-side with pricing.
10
Horsepower
Lathes · Small mills · Compressors
Compare 11 models →
15
Horsepower
Mid-size mills · Small CNCs
Compare 11 models →
Most popular
20
Horsepower
Larger lathes · Surface grinders
Compare 12 models →
25
Horsepower
Production CNCs · Multi-machine
Compare 10 models →
30
Horsepower
Industrial CNCs · Big compressors
Compare 12 models →
40
Horsepower
Heavy CNCs · Big compressors
Compare 13 models →
50
Horsepower
Large CNC mills · Production
Compare 12 models →
60
Horsepower
Industrial chillers · Heaviest
Compare 12 models →
Need a different size? Browse our full rotary phase converter lineup or call 800-417-6568 for a custom build.
How to Choose a Rotary Phase Converter
When choosing a rotary phase converter for sale, it's crucial to assess the power needs of your equipment. Consider factors like horsepower, amperage, kilowatts, and voltage requirements for accurate selection. Different equipment loads may require specific converter types.
It's wise to select a converter with a kilowatt rating that matches your CNC equipment's needs, and opting for a higher capacity allows for future growth and increased power demands. If you want to learn more about how a rotary phase converter can impact your business, contact Phoenix Phase Converters at 800-417-6568 for further assistance.
Benefits of a Rotary Phase Converter
When you’ve found the best rotary phase converter for sale, you can power your facilities to power a range of industrial equipment effectively.
Versatility and Compatibility.
Rotary phase converters offer exceptional adaptability, making them ideal for powering a wide variety of industrial machinery and equipment. They are compatible with woodworking tools, CNC machines, pumps, compressors, and more, providing a versatile solution for numerous industrial applications.
Balanced and Reliable Power
One of the key advantages of a rotary phase converter for sale is its ability to provide balanced and reliable power output. By converting single-phase power into three-phase power with precise control, these converters ensure consistent and stable power delivery to industrial equipment, minimizing the risk of voltage fluctuations and equipment damage.
Cost-Effective Solution
These converters offer a cost-effective solution for businesses seeking to power their machinery with three-phase power. Compared to alternatives such as utility upgrades or renting generators, this type of phase converter is more affordable upfront and incurs lower operational costs over time, making them a budget-friendly choice for industrial facilities.
Easy Installation and Maintenance
Installing and maintaining rotary phase converters is straightforward and hassle-free. These converters are designed for easy integration into existing infrastructure, with simple installation procedures that minimize downtime and disruption to operations. Additionally, a rotary phase converter for sale requires minimal maintenance, reducing the need for costly repairs or servicing.
Scalability for Growing Businesses
Due to their adaptability, rotary converters make it simple for companies to grow and meet increasing power requirements. They may be scaled up to meet changing business needs, adding new machinery or increasing production capacity, giving developing businesses flexibility and adaptability.
Enhanced Automation and Safety
With advancements in technology, modern rotary phase converters for sale come equipped with features that enhance automation and safety in industrial environments. These include built-in safety mechanisms, overload protection, and advanced monitoring capabilities, ensuring the safe and efficient operation of machinery while minimizing the risk of accidents or downtime.
Talk to a Phase Converter Engineer
📞 800-417-6568Free sizing help • Lifetime warranty • Made in USA • Mon–Fri 7AM–5PM MST