VFD Surge Protection and Power Filtering

VFD Brands We Protect

VFD Surge protection for your ABB, Allen Bradley, General Electric, Hitachi, Mitsubishi, Toshiba, Yaskawa, Westinghouse will improve power quality by surge protecting and power filtering the incoming power to the Variable Frequency Drives (VFD). This can be accomplished by installing the TPX-480NN-F surge protector unit at each drive. Or, protect multiple drives by installing a VFD surge protector at drive cabinet or motor control center. For additional surge protection install a small series wired surge protector unit on the circuit feeding the low voltage controls when possible. The VFD surge protector and power filter can be placed at the drive cabinet or individual drive. By being at any of these points you can protect all variable frequency drive VFD equipment from incoming surges/transients from the utility line. In addition the VFD surge protector will protect against all the cross circuit transients generated by the variable frequency drives themselves from switching on and off which damage and degrade equipment overtime in other parts of the facility. Plus, you will clean up transients caused by the drives that can affect electronic loads in other sections of the facility. Surge protection is also recommended to protect VFD equipment when harmonics are an issue.

Surge Suppression for VFD's 

VFDs (variable speed drives) are very common in industry and can provide many years of reliable service. Unfortunately, one of the major causes of VFD failure are electrical surges. From no detectable effect to complete destruction, the effects on equipment can be many. Fortunately, there are surge protection devices (SPDs) on the market that can provide protection for your VFDs. By definition, an electrical surge is a transient electrical voltage or current that occurs in an electrical circuit. Typically, a power surge is an oversupply of electrical voltage from a variety of sources. Sometimes these surges come from the electrical utility, due to switching or equipment failure. Other times, the culprit is an internal surge from equipment inside the facility. Sometimes, the problem is a lightning strike. What kind of damage can a surge do to your VFD? In a word, catastrophic. The front end of a typical drive consists of a semiconductor diode bank. These diodes convert the AC line voltage to a DC voltage and severe overvoltage will destroy these devices. Recently, a massive electrical storm in Illinois destroyed multiple drives in a manufacturing facility. While the cost to replace these drives was a somewhat reasonable figure, the subsequent downtime ran into the hundreds of thousands of dollars. (Written by Jim Davis, Automation Engineer)

Recommendation for protecting logic controls and drives

TPD manufacture many different types of suppressors, so we do not need to take a "one size fits all" approach to protecting equipment.  The three phase suppressor can be placed at the drive cabinet (or individual drive, soft start, MCC or distribution panel feeding the equipment).  By being at any of these points you can protect all downstream equipment from incoming surges/transients from the utility line in addition to all the cross circuit transients generated by equipment switching on and off in other parts of the facility. Plus, you will clean up transients caused by the drives that can affect electronic loads in other sections of the facility.

Only the units installed at or near each drive or on each drive cabinet or MCC feeding the drives can stop the internally generated transients.  Normal load switching of equipment inside any facility can surge other equipment in the facility if no suppressor is placed on each piece of equipment fed from a common bus or distribution panel.  Plus, if lightning should strike the facility or near the facility and inductively couple onto building wiring, if no TPS unit is installed near the equipment, lightning could get onto an overhead bus or get into a distribution panel and spread out to the other circuits on that bus or distribution panel. Also, if any sub panel feeds parking lot lights, signs, security gates, roof top HVAC equipment, or any other outside electrical equipment, lightning could strike at or near the equipment and travel back into the sub panel and then out to other circuits on that sub panel or travel to the distribution panel feeding the sub panel.  Therefore placing surge suppression at the service entrance only is not sufficient to fully protect the equipment and why it is second in priority to installing protection at the equipment level or at the distribution panel/MCC/drive cabinet feeding the individual drives and other pieces of equipment.

Financial Costs of Transient Surges On VFD Equipment

The cost and repair of a single surge event or two at most will typically pay for the price a TPD VFD surge protector. Although labor costs vary, having a specialized technical person show up with parts and pay for travel will have a minimum charge of $ 500 to $1500 on average. This means for a small upfront investment our surge suppressor products will lead to enormous life cycle savings!

End User Benefits

Variable frequency drives are affected by transient surges and can be costly to maintain. The installation of Transient Voltage Surge Suppressors can contribute to a reduction in repair costs. It is recommended to continually monitor these costs and compare it to already protected and or reliable equipment. Whether it is storms or utility power problems it is easy to compare trouble locations to others. It's is these trouble locations that usually require surge suppression 95% of the time. It is these location that the payback on the surge suppression will by far exceed the price of the surge suppressor.

Success Stories

PDF – Cold Storage – Reduce bulb/ballast replacement…Protect from lightning…ROI in less than 1 year
PDF – VFD – Reduce troubleshooting time & lost production…40% reduction in electrical maintenance