If you’re adding new equipment to your shop, one of the first questions is often: “How do you wire a phase converter safely?” Getting this step right isn’t just about powering up your machine. Safe wiring protects your equipment, prevents costly breakdowns, and keeps your shop running without interruptions. Done wrong, it can lead to overheating, poor performance, or even serious hazards.

Here’s what you need to know before wiring a phase converter.

Understand What a Phase Converter Does

A phase converter takes single-phase power and turns it into three-phase power, which most industrial machines require. Whether you’re running a CNC, welder, or compressor, the wiring has to be correct so the converter delivers steady, balanced power. Without proper wiring, your machines may run unevenly, overheat, or fail to start.

If you’re unsure which setup fits your needs, start by reviewing the available phase converters and their requirements. We also have a phase converter sizing tool to help you size your application.

Follow Electrical Codes

Always follow the National Electrical Code (NEC) and local building rules. These codes aren’t just guidelines—they’re in place to prevent shocks, fires, and unsafe installations. Skipping permits or inspections may save time upfront, but can result in more costly repairs or fines later.

Size Your Wire Correctly

Wire size is one of the most important factors in safe wiring. If the wire is too small, it can overheat and cause voltage drops that wear out your equipment. Larger machines need thicker wire, and long wire runs often require upsizing to keep voltage steady.

For example, a 5 HP motor can run on a smaller gauge wire over moderate distances, while a 20 HP motor demands thicker wire and possibly shorter runs. Planning wire size with future expansion in mind can also save you from rewiring later. Oversizing slightly is often a smart move.

Proper sizing not only keeps your equipment safe but also reduces strain on your phase converters, helping them perform more reliably.

Protect the Circuit

Every installation needs proper overcurrent protection. Circuit breakers or fuses guard against overloads and short circuits, cutting off power before damage occurs. The breaker has to match the converter’s input and the equipment load. An electrician can make sure your breaker panel is ready to handle the additional current safely.

Ground the System Properly

Grounding is a non-negotiable step. A ground wire gives electricity a safe path in case of a fault, which protects you and your equipment. The ground should be the correct gauge for the circuit and securely connected to both the converter and the main panel. Skipping this step is one of the most dangerous mistakes in wiring.

Use Disconnects and Conduit

A disconnect switch is not always necessary, but having one nearby allows you to cut power to the phase converter. Conduit protects your wires from moisture, heat, and physical damage, which is especially important in a busy shop where wires are exposed to wear and tear.

Balance the Load

Phase converters are built to deliver balanced power, but the way you wire your shop matters too. If you’re running multiple machines, using a subpanel can help distribute power evenly and keep wiring organized. Balanced loads mean smoother operation and fewer performance issues.

Hire a Licensed Electrician

Even if you’re comfortable with basic wiring, hiring a licensed electrician is recommended. A licensed electrician can help ensure your setup is safe, code-compliant, and designed to last. Professional installation is often cheaper than repairing equipment damaged by improper wiring.

Plan for the Future

Think beyond today’s setup. Maybe you’ll add another welder, a larger CNC, or rearrange your machines. Oversizing wires, conduit, and breakers now can save you money and downtime later. Future-proofing your installation is a simple way to avoid starting from scratch.

Quick Safety Checklist

  • Review NEC and local electrical codes before you start.
  • Choose wire size based on machine load and distance.
  • Install the right breaker or fuse for your converter.
  • Always ground the system properly.
  • Use conduit to protect wires.
  • Consider adding a disconnect switch near the converter.
  • Consider a subpanel for multiple machines.
  • Hire a licensed electrician.

The Takeaway

So, how do you wire a phase converter safely? Follow the above steps, but most importantly, don’t cut corners; safety and reliability go hand in hand.

We help shop owners every day with installation guidance and dependable equipment. If you’re preparing your shop, we’ll make sure you have the right phase converters for the job and the support to set them up safely.