EMA Inc. | Norcross, GA | Tech Articles

Allen Bradley Powerflex 6000 – The Voltage Source Alternative to the Powerflex 7000

The cascaded H-bridge topology is the most common design used in the Medium Voltage variable frequency drive industry. Rockwell/Allen Bradley has been transitioning customers to their voltage-source medium voltage drive: The Powerflex6000. This replaces the older current-source Powerflex7000 medium voltage variable frequency drive. The Powerflex 6000 design is similar to many other cascaded H-bridge topology drives, like the Robicon/Siemens perfect harmony variable frequency drive. EMA has experience in repair and service of the Powerflex7000 and Powerflex6000. Unlike low voltage VFDs,…

EMA has VFD customers all across North America

A Different Approach to Field Service of Variable Frequency Drives

Variable Frequency Drive troubleshooting is an art that requires understanding of VFDs themselves and why certain issues occur. EMA does more than troubleshoot to find the problem, we offer solutions for solving the problem AND prevent it from happening in the future. Systematic Approach to VFD Field Service Because we’ve been around for over 30 years, we’re well versed in any VFD-related issue you could possibly throw at us. We’ve been blessed to “grow up” as VFDs have grown up,…

An Overview of Variable Frequency Drives

At EMA, we often laugh about how the quickest way to lose friends at a party is to discuss what we do for a living; in fact, we made a hilarious commercial poking fun at this. All joking aside, variable frequency drives — aka “adjustable-speed drives,” “inverters,” “drives,” “VFDs,” and “frequency inverters” — are extremely common in all types of applications and perform a lot of the behind-the-scenes work that makes many industries go. Although most people cannot tell you what VFDs…

VFD vs Softstarter: Which one do you need? 

At EMA, we get this question a lot: “Do I need a softstarter or a VFD for this?” and the purpose of this article is to help answer that. Softstarters and VFDs both control induction motors but there are several distinct differences that are important to understand when determining which is best for you; some of the major distinctions are: the application, available power grid, and starting torque required.  Understanding Softstarters The application of the motor is a major consideration when determining whether a VFD or a softstart is necessary. A softstarter is…

A man standing next to a wall of remote monitoring tools

What you need to know about DriveScan Remote Monitoring Tool

A basic internet search of medium voltage drive manufacturers often creates more questions than answers, with dense blocks of dry information and little else in the way of conversational language. That’s where EMA Inc. stands out from the crowd. We’re here to talk to you like a person, whether you do business with us or not. Our innovative, industry-leading DriveScan remote monitoring tool provides continuous, comprehensive monitoring for medium voltage drives — perfect for drive health monitoring, predictive actions, increased drive uptime,…

Buyer’s Guide: How to Choose a Medium Voltage VFD

Do you find yourself in the market for a new medium voltage variable frequency drive? Where do you begin? Well, you’ve come to the right place. EMA is the industry leader when it comes to variable frequency drives, and we’re happy to point you in the right direction. This is a big investment, one that should last you 20 years or more, and there are several factors to consider before purchasing; not all variable frequency drives are created equally. Some of the more important factors are: capacitor type, pre-charge circuitry,…

peace of mind with remote monitoring drives & medium voltage vfd

VFD Remote Monitoring Brings Peace of Mind

Who doesn’t need a little extra peace in their life? You deal with enough stress in your job; failures on your Medium Voltage Drives should not be one of them. EMA and Powerside have partnered to develop a solution to remotely monitor the health of your Medium Voltage VFDs from anywhere in the world. The way you currently monitor your Medium Voltage VFDs does not bring about peace in your life, it keeps you up at night, wondering what will…

Strong Year for Medium Voltage VFD Repair Service Business

2020 has most assuredly been a strange year. We’ve had to deal with Covid issues just like almost every other business in America, but this has been a strong year for our medium voltage VFD repair and service business. We’ve had this strong year repairing and servicing medium voltage VFDs despite the overall economic slowdown. We attribute it to several factors, and the first one is going to sound like bragging (but it’s simply a fact) Our reputation for repair…

Changes in the Siemens MV VFD Brand Family

Over the past 10 years, EMA has been heavily involved with repairing and servicing Medium Voltage VFDs. The most common drive we service, both in the field and in our repair shop, is the Siemens Perfect Harmony MV VFD. The Siemens/Robicon Perfect Harmony Drive was the first successful voltage-source medium voltage VFD in the industry. The H-Bridge design uses low voltage, single-phase output power modules cascaded together to generate medium voltage using low voltage power components. This simple and inexpensive…

Remote Monitoring Medium Voltage Drive Saves Time and Headaches

There is never a good time for a Medium Voltage Drive to fail. Does this scenario sound familiar to you? Your Medium Voltage Drive fails in the middle of the night, your on-call technician, although very sharp, is not a VFD expert, everyone at the manufacture’s tech support is asleep, and the drive’s fault code has you scratching your head. Before the days of remote monitoring, this scenario would cost your production days or even weeks of downtime as you…