Rotary Phase Converter Control Panels
Got a three-phase motor sitting on the shelf? Pair it with an NAPCco control panel and you’ve got a reliable rotary phase converter that runs three-phase equipment from your single-phase supply. Each rotary phase converter control panel uses the same digitally controlled start circuit, built-in motor starter and CNC voltage balancing as our Pro-Line units. You bring the idler motor, we build the panel.
Every panel is wired and tested at our New Berlin, Wisconsin facility by a UL 508A panel builder*, then backed by a 10-year parts and lifetime labor warranty and free phone support for the life of your converter. Models run from 3 HP to 60 HP, covering everything from home workshops to commercial shops.
Before you order, you’ll need a compatible three-phase idler motor. Not sure yours will work? Give us a call and we’ll check it with you.
- 10-Year Parts/Lifetime Labor Warranty
- Made in the USA
- BBB A+
- Sizing Guarantee
- 24/7 Free Lifetime Support
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Control Panel Features
Control Panel Features
- Built-In Motor Starter with Start/Stop Switch
- Digitally Controlled and Protected Start Circuit
- Total Power Shutoff Protection
- CNC Voltage Balancing
- Power "ON" Indicator Light
- Easy Installation
- Distribution Block Connections
- Power Factor Corrected
- Made in the USA
- 10-Year Parts/Lifetime Labor Warranty
Idler Motor Requirements
- Three-Phase Motor Supplied by You
- T-Frame, Built 1965 or Newer
- 2-Pole (3,400 to 3,600 RPM)
- 4-Pole (1,700 to 1,800 RPM)
- Horsepower Matched to Your Panel
- Free Compatibility Check by Phone
Available Upgrades
- UL-Listed Control Panels
- Wireless Remote Starter
- Wired Remote Switches
- 480 Volt Control Panels
- NEMA 3R Outdoor Enclosures
- Rubber Mounting Feet
- Voltage Meters
- Automatic Controls
- Power Time Delays
- Plugs and Outlets
- Every panel has a magnetic three-phase motor starter built in
- Green start and red stop push buttons sit on the front cover
- There's no separate starter to buy; it's already wired in
- Uses the same patented differential voltage sensing start circuit as our Pro-Line converters
- Checks that the start sequence is running correctly, with no mechanical start relays that'll need replacement
- A safety timer times out to protect the start capacitors from failure
- Drops all three legs at the same time if you lose single-phase power
- Stops your motors from trying to run on a single-phase when the power comes back
- Keeps your idler motor and machines protected through outages
- Phase-to-phase voltage balanced to within 2% to 5%
- Safe for CNC mills, CNC lathes, machining centers, and other voltage-sensitive equipment
- Handles standard motors, resistive and inductive loads just as well
- Front-mounted light shows you when the converter's running
- Easy to check at a glance, even in a loud shop
- Sits alongside the stop button so you can shut down fast
- Removable back plate reduces enclosure weight for easier wall mounting
- Knockouts on the bottom and right side suit most conduit runs
- Connect your idler motor using the wiring diagram on its nameplate or junction box
- Oversized distribution blocks for the single-phase input and three-phase output
- Strip, insert and tighten for a quick connection, with no special connectors needed
- Clearly labeled L1, L2 and T1, T2, and T3 terminals keep wiring and inspections simple
- Run capacitors correct the power factor of your idler motor
- Cuts the current your converter draws from the single-phase supply
- Helps your idler run cooler and more efficiently
- Use any three-phase T-frame motor built in 1965 or later, 2-pole or 4-pole
- Match the motor's horsepower to the panel, so a 10 HP motor goes with the CP-10 and a 15 HP motor with the CP-15
- Got a 7.5 HP motor? The CP-7 is the 7.5 HP rotary phase converter control panel to pair with it
- Call us with the details from your motor's nameplate, and we'll confirm it's a match before you order
- Built and tested at our facility in New Berlin, Wisconsin
- Constructed by a UL 508A panel shop to recognized industrial standards
- DIN rail-mounted components give you a clean interior that's easy to inspect
- Backed by a 10-year parts and lifetime labor warranty and free phone support for the life of your converter
Rotary Phase Converter Control Panel Model Sizing Chart
Find the right CP panel for your application using the chart. Prices are for the control panel only, so you’ll need to add a three-phase idler motor to complete your converter.
Need a hand with sizing? Call us at 877-545-2926 or use the sizing tool.
Installing Your Rotary Phase Converter Panel
The CP panel is designed for straightforward installation by a licensed electrician, with a removable back plate, terminal block connections, and oversized power distribution blocks. Connect your idler motor using the wiring diagram on its nameplate, and you’re ready to go.
Phase Converter Control Panel FAQs
CP panels start at $289 for the CP-3 and go up to $1,029 for the CP-60. Prices cover the control panel only, so you’ll need to factor in a compatible three-phase idler motor if you don’t already have one. You can select upgrades like a NEMA 3R outdoor enclosure, UL listing, or wireless remote starter on each product page, priced separately.
You’ll need a three-phase T-frame motor made in 1965 or later, either 2-pole (3,400 to 3,600 RPM) or 4-pole (1,700 to 1,800 RPM). Match the horsepower to the panel, so a 20 HP motor pairs with the CP-20. If you’re not sure your motor will work, call us with the nameplate details, and we’ll check it for you.
Start with your idler motor, since each panel is built around a specific horsepower rating. Then confirm the phase converter can handle your machines, keeping in mind that hard-starting loads like air compressors need more capacity than easy loads like table saws. The sizing chart and sizing tool will help, or you can call us, and we’ll size it with you at no charge.
Yes. CP-5 to CP-60 panels balance voltage to within 2% to 5%, which suits CNC mills, lathes, and machining centers. For CNC, resistive and inductive loads, size your converter at double the load.
If you’ve already got a suitable three-phase motor, a CP panel is the cheaper way to get the same start circuit, power protection, and voltage balancing as our complete rotary phase converter systems. If you don’t, a Pro-Line rotary phase converter ships fully assembled with a custom ABB/Baldor idler generator built for phase conversion. Not sure which makes more sense for your setup? Give us a call, and we’ll talk it through.
Yes. Every CP panel is designed and built in New Berlin, Wisconsin. We assemble them in a UL 508A* panel shop with color-coded wires per phase, so the interior is clean and easy to inspect.
Yes. Installation should be carried out by a licensed electrician and meet all national, state and local electrical codes. They’ll let you know if your machines need a transformer to match your supply voltage. The removable back plate, clearly labeled distribution blocks and conduit knockouts keep the job simple, and your electrician will connect the idler motor using the wiring diagram on its nameplate.
Need help choosing the right CP control panel? Call us!
Talk to an application engineer for free
Our application engineers check the sizing on every order before it ships. If you’re not sure which panel suits your idler motor and equipment, give us a call before you buy.
* Not every panel is UL-Listed. UL-Listing is an added option you can specify when you place your order.