In our 32 plus years of business we have NEVER seen a supply shortage like we are currently experiencing. When my career first started, EMA was a “stocking distributor” for multiple VFD brands. We eventually shifted away from that business model because drives were so readily available we simply did not see the advantage of keeping a large stock. My how the times have changed?! Drives that used to be shelf items are now experiencing lead times of 20, 30,…
With the global supply chain shortage in full force, our customers are having a very hard time finding a drive available in a reasonable amount of time. Major VFD manufacturers have increased their lead times and prices dramatically in the past year. At EMA we’ve been accumulating medium voltage variable frequency drives from canceled projects and plant closures for years, giving us one of the largest stocks of medium voltage drives in the country. These drives come with a full…
Variable frequency drives often fall into a “set it and forget it” mode. Modern VFDs are generally reliable so once they’re started up, they’re often given very little attention until a failure occurs, in which all hell breaks loose trying to resolve it. Routine maintenance or “preventative maintenance” is often overlooked or pushed aside by operations managers who are looking to squeeze in every last ounce of production possible. There is, however, significant data to justify routine, preventative maintenance on…
If your company is considering purchasing Medium Voltage Variable Frequency Drives, there are multiple factors to consider besides upfront cost. We cannot cover all of these in this short article, but these are a few to think about during the decision-making process. Application Unlike low voltage drives, where there are two very distinct markets for two very distinct load types: Constant and Variable Torque, most medium voltage drives are built for variable torque applications such as pumps and fans since…
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,…
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,…
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…
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…
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,…
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,…
