Phase Converter for a CNC Router

Phase Converter for a CNC Router

CNC routers are workhorses in woodworking, sign-making, and fabrication shops—but most require three-phase power to run their spindle motors at rated speed and torque. A rotary phase converter gives you clean, stable three-phase power from your single-phase utility service, without the cost of a utility upgrade.

Sizing Depends on Your Setup

CNC routers often include a vacuum table to hold down workpieces, and vacuum pumps are heavy-starting loads. That means the sizing formula changes depending on what is attached to your machine.

No Vacuum Table

One Vacuum Table (Single Pump)

Two Vacuum Pumps

Vacuum pumps use a 3× multiplier because they are hard-starting loads—they draw significantly more current on startup than when running. Undersizing here is the most common mistake CNC router owners make.

Always Choose the PL Model for CNC

We always recommend the PL series for CNC routers. CNC machines are controlled by computers that are sensitive to power quality. The PL model includes pushbutton controls and a built-in voltage monitor, protecting your machine from voltage fluctuations and preventing dangerous automatic restarts after a power interruption.

Sizing Example

A CNC router with a 10 HP spindle and a single 5 HP vacuum pump: (5 × 3) + 10 = 25 HP converter → GP25PL.

Why Not a VFD?

Variable frequency drives work well for a single spindle motor but cannot power your vacuum pump, coolant system, or control panel simultaneously. A rotary phase converter powers the entire machine from one connection point.

📞 800-417-6568 — Give us your spindle and vacuum HP and we will size it for you in minutes.