​ ​ Tech Articles | EMA Inc. | Page 2
Loading
EMA Inc.
770-448-4644770-448-4644 201-594-0900

Tech Articles

Eaton SC9000 Series MV VFD Repair and Overview

EMA repairs and provides preventive and predictive maintenance on  the Eaton SC9000 MV VFD.  We  have a fully functional test stand for these units. We repair most Medium Voltage VFDs including the Eaton SC9000, the Siemens Robicon Perfect Harmony, the Toshiba T300MVi , Ansaldo / Ross Hill, ABB, Yaskawa, and others.  Here’s a short overview of the Eaton SC9000:  The Eaton SC9000 series MV VFD is a 24 pulse three level topology VFD with integrated phase shifting transformer. In today’s…

Continue Reading ››

Refurbished Medium Voltage VFDs for sale

EMA has refurbished medium voltage VFDs in stock and for sale.  They carry a full warranty and are fully tested and operational.  Most are rated at 4160 volts. As far as we know, we have the largest stock of refurbished medium voltage VFDs in the world.  There are several reasons to consider a refurbished medium voltage VFD.  Cost..  Significant cost savings are accomplished by using refurbished medium voltage VFDs.   Delivery..  Most of the refurbished medium voltage VFDs we have in…

Continue Reading ››

Perfect Harmony VFD

EMA: 29 years of Medium and Low Voltage Service

EMA is thankful to be celebrating 29 years of Medium and Low Voltage Drive service.  We have the best customers in the world, located all over the globe.   EMA recently performed medium voltage VFD service in Qatar, France, Canada, Columbia,  and Mexico.  In addition we’ve been doing medium voltage VFD service on off shore oil platforms in both the Gulf of Mexico and California, and a number of industrial plants and municipal water and waste water plants all over the…

Continue Reading ››

The Modern Day Linebackers of Medium Voltage Drive Service

While preparing for the upcoming NFL draft, I am struck by how often we hear the draft pundits refer to the “modern day linebacker”: a player who’d be considered undersized by traditionalists but whose speed and agility allow him to cover a wide area and be utilized in a variety of ways. As offensive schemes and rules evolve to promote offense in 5-wide, empty backfield configurations, the defenders, particularly linebackers, are forced to be hybrid-type players. 2018 draft picks Roquan…

Continue Reading ››

Eaton MCC

Square D and Eaton MCC medium voltage Softstarters

We work on quite a few Square D and Eaton MCC Softstarters.   Most of them, as it turns out, are actually manufactured by Motortronics. Motortronics has a done a great job at capturing the medium voltage softstarter market.  Square D, Eaton, and other MCC manufacturers simply brand label the Motortronics softstarter and install. This isn’t to denigrate either Square D or Eaton MCC medium voltage softstarters.  Brand labeling is a common and efficient practice by a number of MCC medium…

Continue Reading ››

LNG Transport Ship

Siemens Robicon Perfect Harmony VFDs on LNG Ships

We recently had the opportunity to service  Siemens Robicon Perfect Harmony VFDs on a LNG Carrier (Ship) in the middle east.   When natural gas is cooled to minus 259 degrees,  it assumes a liquid state.  Liquefied Natural Gas (LNG) is much more efficient to transport than  compressed natural gas (CNG).  It is particularly suited for large LNG Transport Ships. The problem is keeping it cool.  Many LNG Ships use large compressors to lower nitrogen to around minus 321 degrees where…

Continue Reading ››

Pre Charge on Siemens Robicon Perfect Harmony VFD

One of the key features of all low voltage VFDs is their ability to softly charge the DC bus capacitors. This feature is not a readily available on the Siemens/Robicon Perfect Harmony MV VFDs. The Perfect Harmony VFD can be easily modified to include this feature.  Soft (or Pre) charging the bus capacitors limits the inrush current upon power up, and prevents damage to transformers, power devices, and other connected devices. Within the Siemens Robicon Perfect Harmony medium voltage VFD…

Continue Reading ››

Robicon Siemens Perfect Harmony Preventive Maintenance (PM)

Preventive Maintenance(PM)  on any VFD is in essence downtime prevention.  That’s especially true for PM on Robicon Siemens Perfect Harmony VFDs. The Robicon Siemens Perfect Harmony VFD has been around a long time.  Siemens Robicon did a great job at providing a reliable voltage source medium voltage VFD at a time when few others could.  The Siemens Robicon Perfect Harmony VFD is found in applications world wide, and many of them have been operating for over 10 years.  Preventive Maintenance…

Continue Reading ››

Medium Voltage Power Cell

Field (Site) Testing Siemens / Robicon Perfect Harmony Power Cells

Siemens/Robicon Perfect Harmony Power Cells (power modules) can be tested in the field, at the job site. Field testing the Perfect Harmony Power Cells (power modules) takes special equipment, which we developed, exclusively for testing the Siemens / Robicon power cells (power modules).   We also repair and test the power cells at our Norcross, GA facility, using a complete Siemens/Robicon Perfect Harmony drive test stand.    It is not always practical to ship Siemens/Robicon power cells (power modules) to…

Continue Reading ››

Low Cost Medium Voltage VFDs

Medium Voltage VFDs are coming down in price as the market grows more competitive.  Nonetheless, they remain expensive. The cost is not only the initial price, but the size of medium voltage VFDs means the installation costs are significant.   All that said,  at EMA we love medium voltage VFDs, enjoy repairing them, and selling them.  They are very reliable, and are becoming more and more commonplace.  One way to greatly reduce the purchase price and get low cost medium…

Continue Reading ››

123...15...Last »