Recommended Phase Converter for a Haas VF-2 Vertical CNC Machine

The Haas VF-2 is one of the most popular CNC machining centers in small and mid-size shops. Here is the definitive guide to running it on a phase converter — sizing, wiring, and what to expect.

VF-2 Specifications

Spindle HP 20 HP (standard), 30 HP (optional)
Max HP 30 HP
Spindle Speed 8,100 RPM (standard)
Voltage 230V or 460V three-phase
Control Haas CNC — internal servo drives and VFD

Which Phase Converter?

CNC machines are hard-starting loads — use the 2.0x multiplier on spindle HP:

  • Standard VF-2 (20 HP spindle): 20 x 2.0 = 40 HP → GP40NL
  • High-power VF-2 (30 HP spindle): 30 x 2.0 = 60 HP → GP60NL

Do not undersize. A 20 HP converter on a 20 HP CNC spindle will cause voltage sag, servo faults, and nuisance E-stops. The GP40NL gives you the headroom the Haas control demands.

Wiring Notes

  • Single-phase input to converter: size wire for 2x the CNC three-phase FLA
  • Three-phase output from converter to machine: standard wire per CNC nameplate FLA
  • Grounding: converter ground bonded to machine ground and panel ground — single ground reference
  • Voltage balance check: measure L1-L2, L1-L3, L2-L3 at the machine input terminals under full spindle load — target under 2% imbalance

What About 460V VF-2 Machines?

If your VF-2 is wired for 460V three-phase, you need a step-up transformer after the phase converter, or a 460V-output phase converter (NH/PH Series). Call (800) 417-6568 and we will spec the right combination.

Ready to get powered up?

Free sizing help. Made in Phoenix, AZ. Lifetime warranty.

Shop Phase Converters

(800) 417-6568

Related Articles

Haas VF-2 — FAQ

Will the phase converter affect Haas warranty?

Using a phase converter does not void Haas machine warranty — Haas supports phase converter operation. What Haas requires is stable, balanced three-phase power — which a properly sized Phoenix converter provides.

My VF-2 shows a power fault — what should I check?

Check voltage balance first: measure all three legs at the machine input under full spindle load. Over 3% imbalance can cause Haas power fault alarms. Also verify your single-phase input voltage is stable at 230–240V.

Related Articles

Questions? Talk to an engineer.

Free sizing help. Made in Phoenix, AZ. Lifetime warranty on every unit.

Shop Phase Converters

(800) 417-6568