Digital (VFD) vs Rotary Phase Converters: Why Rotary Is the Smarter Choice

If your shop is single-phase and your equipment must be powered three-phase, you have two choices: Digital (VFD) Phase Converters or Rotary Phase Converters. Either way, you will be able to power your three-phase equipment from your single-phase power source.

But they are utilized for various purposes, and selecting the proper one can be a matter of years of consistency versus headaches day and night.

So, here today, we will look at what both of these types of converters are and compare them for further understanding. We will also touch on why rotary phase converters are the better choice. So, let's get started.

What Is a Digital (VFD) Phase Converter?

A VFD or digital phase converter produces three-phase power from one-phase input through solid-state circuitry. It works by rapidly switching the transistors to create the additional phases.

Pros 

• Compact size with no moving parts

• Suitable for energizing a single continuous load

• Has motor control features, including soft start, ramp-up, or speed change

Cons 

• Electrical noise, grounding, and load type sensitive

• Can malfunction with regenerative loads such as machines that return energy to the system when braking, CNCs, compressors, elevators, etc.

• Typically rated for one machine at a time

• Repair is costly and usually involves sending the unit back to the manufacturer 

What is a Rotary Phase Converter? 

A rotary phase converter employs an idler generator motor to produce a real third leg of power from single-phase power directly. This supplies clean, balanced three-phase power for several loads.

Pros 

• Heavy-duty, tried-and-true construction

• May operate several machines at the same time

• Will never trip on hard-starting motors, pumps, compressors, or CNCs

• Very long life with very minimal maintenance

• Typically easy and low-cost to fix (uses common bearings and capacitors)
  

Cons 

• Larger size than digital converters

• Has moving parts (idler motor), which makes some noise
  

SIde-by-Side Comparison 

When choosing between a digital (VFD) converter and a rotary phase converter, it is helpful to compare the two side-by-side. Here's a side-by-side comparison of both solutions along the most important factors of consideration. 

Why Choose Rotary? 

If you are running heavy machinery, such as mills, lathes, welders, plumps, HVAC equipment, or woodshop work, then a rotary phase converter is your best long-term, extremely reliable option. It provides true three-phase power, reduces downtime, and can run several machines without the obstructions of sensitive electronics. 

While digital solutions may find application in one-of-a-kind, single-motor situations, the versatility and dependability of rotary phase converters will probably be a better fit for the majority of shops, farms, and buildings than a digital solution. 

Bottom Line 

Your power equipment is the heartbeat of your business. The improper power solution can result in lost production, costly repair, and infinite aggravation. Rotary phase converters remain the gold standard for rugged, versatile, dependable three-phase power. 

At Phoenix Phase Converters, we have established a reputation by offering dependable, enduring converters. If you require any expert help in sizing and installing for your shop, we can assist you. 

Get in touch with us today and boldly power your machines.