GPX Digital Series Phase Converters
The GPX Digital Series brings modern solid-state technology to single-phase to three-phase conversion — featuring an LCD status display, electronic soft-start, AutoStart with load detection, and real-time voltage monitoring. The intelligent alternative to traditional rotary converters.
Digital control meets rotary reliability
The GPX Series uses an advanced solid-state control system paired with a high-efficiency idler motor. Instead of fixed capacitors, the GPX uses electronically controlled capacitor switching to maintain voltage balance across a wide load range — similar to the AutoLink system but with digital precision.
LCD Display
The front-panel LCD display shows you what's happening in real time:
- Output voltages — all three phases, continuously updated
- Voltage imbalance percentage — know your balance at a glance
- Load status — active load detection and AutoStart state
- Fault codes — clear diagnostic messages instead of guessing
- Operating hours — track maintenance intervals
Electronic Soft-Start
Hard-starting equipment causes the most stress on phase converters and the machines they power. The GPX's electronic soft-start ramps up the voltage gradually, reducing:
- Inrush current on startup — reduces circuit breaker nuisance tripping
- Mechanical shock to motor windings and bearings
- Voltage sag that can trip other equipment on the same circuit
- Wear on capacitors and motor contactors
AutoStart with Load Detection
The GPX monitors its output for a connected load. When you turn on a machine, the GPX starts automatically. When the machine shuts off, the GPX shuts down after a configurable delay. No manual start lever needed.
GPX vs NL Series: Which to Choose?
- Choose GPX when you want soft-start, digital diagnostics, or hands-off AutoStart
- Choose GPX for single high-value CNC machines where monitoring matters
- Choose NL for simplicity, proven reliability, and lower first cost
- Choose NL when running multiple machines simultaneously (GPX is optimized for single-machine use)
Key Features
- Solid-state digital control system
- LCD front-panel display — voltage, balance, status, fault codes
- Electronic soft-start — gentle ramp-up for hard loads
- AutoStart with load detection — fully automatic operation
- Real-time voltage balance monitoring
- NEMA 4 steel enclosure
- TEFC cast-iron idler motor
- Lifetime transferable warranty
- Made in Phoenix, Arizona
Sizing the GPX Digital Series
Same multipliers as other Phoenix series. Soft-start reduces inrush but doesn't change sizing — always use the motor HP with the correct load multiplier.
| Load Type | Multiplier | Notes |
|---|---|---|
| Easy (saws, grinders) | × 1.0 | Soft-start reduces inrush |
| Medium (pumps, lathes) | × 1.5 | — |
| Hard (CNC, press brakes) | × 2.0 | Soft-start especially useful |
| Very Hard (compressors) | × 2.5 | Soft-start critical here |
GPX Best Use Cases
- Single machine setup where you want full automation
- Hard-starting loads where soft-start reduces breaker trips
- When you want diagnostic readout instead of guessing at problems
- Clean shops or offices where a display adds professional appearance
GPX Digital Series Lineup
| Model | HP | Input | Output | Display | Soft-Start | AutoStart |
|---|---|---|---|---|---|---|
| GPX3L | 3 HP | 230V 1Ø | 230V 3Ø | LCD | Electronic | Included |
| GPX5L | 5 HP | 230V 1Ø | 230V 3Ø | LCD | Electronic | Included |
| GPX7.5L | 7.5 HP | 230V 1Ø | 230V 3Ø | LCD | Electronic | Included |
| GPX10L | 10 HP | 230V 1Ø | 230V 3Ø | LCD | Electronic | Included |
| GPX15L | 15 HP | 230V 1Ø | 230V 3Ø | LCD | Electronic | Included |
| GPX20L | 20 HP | 230V 1Ø | 230V 3Ø | LCD | Electronic | Included |
| GPX25L | 25 HP | 230V 1Ø | 230V 3Ø | LCD | Electronic | Included |
| GPX30L | 30 HP | 230V 1Ø | 230V 3Ø | LCD | Electronic | Included |
| GPX40L | 40 HP | 230V 1Ø | 230V 3Ø | LCD | Electronic | Included |
| GPX50L | 50 HP | 230V 1Ø | 230V 3Ø | LCD | Electronic | Included |
| GPX60L | 60 HP | 230V 1Ø | 230V 3Ø | LCD | Electronic | Included |
| GPX75L | 75 HP | 230V 1Ø | 230V 3Ø | LCD | Electronic | Included |
| GPX100L | 100 HP | 230V 1Ø | 230V 3Ø | LCD | Electronic | Included |
Buy the GPX Digital Series at phoenixphaseconverters.com or call (800) 417-6568.
GPX Digital questions
Does the GPX replace the idler motor with pure electronics?
No. The GPX still uses a high-efficiency TEFC cast-iron idler motor to generate the third leg — this is what makes it a true rotary phase converter. The "digital" and "solid-state" refers to the control system, capacitor switching, monitoring, and soft-start electronics. The core conversion method is the same proven rotary technology.
What fault codes does the LCD display?
The GPX display shows codes for: over-voltage, under-voltage, voltage imbalance above threshold, over-temperature, input phase loss, and load detection timeout. Each code has a corresponding meaning in the manual, making troubleshooting much faster than a conventional converter where you have to guess at problems.
Can I disable AutoStart if I want to start it manually?
Yes. The AutoStart function can be enabled or disabled via the front panel. Some users prefer to start the converter manually before powering up their equipment — particularly with very sensitive CNC controls — and the GPX accommodates both workflows.
Is the GPX compatible with CNC machines?
Yes. The GPX's electronic voltage balancing and soft-start make it well-suited for CNC applications. For best CNC performance with tighter voltage balance specs, compare the GPX Digital with the PL Series — both are good options for CNC, and we can help you choose based on your specific machine.
All GPX Digital Models
| Model | HP | Input | Output | Enclosure | Warranty | Buy |
|---|---|---|---|---|---|---|
| GPX15L | 15 HP | 230V 1Ø | 230V 3Ø | NEMA 4 | Lifetime | Buy → |
| GPX15ASL | 15 HP | 230V 1Ø | 230V 3Ø | NEMA 4 | Lifetime | Buy → |
| GPX20L | 20 HP | 230V 1Ø | 230V 3Ø | NEMA 4 | Lifetime | Buy → |
| GPX20ASL | 20 HP | 230V 1Ø | 230V 3Ø | NEMA 4 | Lifetime | Buy → |
| GPX25L | 25 HP | 230V 1Ø | 230V 3Ø | NEMA 4 | Lifetime | Buy → |
| GPX25ASL | 25 HP | 230V 1Ø | 230V 3Ø | NEMA 4 | Lifetime | Buy → |
| GPX30L | 30 HP | 230V 1Ø | 230V 3Ø | NEMA 4 | Lifetime | Buy → |
| GPX30ASL | 30 HP | 230V 1Ø | 230V 3Ø | NEMA 4 | Lifetime | Buy → |
| GPX40L | 40 HP | 230V 1Ø | 230V 3Ø | NEMA 4 | Lifetime | Buy → |
| GPX40ASL | 40 HP | 230V 1Ø | 230V 3Ø | NEMA 4 | Lifetime | Buy → |
| GPX50L | 50 HP | 230V 1Ø | 230V 3Ø | NEMA 4 | Lifetime | Buy → |
| GPX50ASL | 50 HP | 230V 1Ø | 230V 3Ø | NEMA 4 | Lifetime | Buy → |
| GPX60L | 60 HP | 230V 1Ø | 230V 3Ø | NEMA 4 | Lifetime | Buy → |
| GPX75L | 75 HP | 230V 1Ø | 230V 3Ø | NEMA 4 | Lifetime | Buy → |
| GPX100L | 100 HP | 230V 1Ø | 230V 3Ø | NEMA 4 | Lifetime | Buy → |