Motor Protection

SineWave Guardian® and dV Sentry® Filters

Three-phase load-side solutions for power quality in systems using Variable Frequency Drives

Problems that can occur without motor protection filtering:
• Damage to motor bearings
• Unexpected ground fault trips
• Erratic behavior of VFDs and PLCs
• Premature motor insulation failure
• Cable damage

How Variable Frequency Drives (VFDs) Work
VFDs serve as a way of controlling the speed of AC motors by varying the frequency of the power source using pulse width modulation (PWM). This is done by switching the transistors, IGBTs, or thyristors, on and off continuously. While the introduction of VFDs has brought precise control of motors and greater energy savings, it has also introduced new problems that, left unaddressed, can cause downtime.

You may experience ground fault trips, which can cause downtime when your drive trips. When adding a VFD to your system, it can add common-mode voltage, which leads to unusually high current in your ground fault detection circuit. This can trip the ground fault sensor, which disables your equipment and stops production.

The Destructive Effects of Power Distortions
The presence of 3-phase power distortions between VFDs and motors can damage equipment, jeopardize productivity and decrease profitability

Motor Protection is Critical MTE offers a full line of best-in-class products to protect motors and improve productivity.

RL reactors (for cable leads up to approximately 300 ft.)
RL reactors are unequaled in absorbing power line disturbances. They are built to withstand even the most severe power spikes. They reduce nuisance tripping, reduce harmonic distortion and minimize long lead effects.

dV Sentry™ filters (for cable leads up to approximately 1,000 ft.) The dV Sentry, with its patented Triple Defense Core, is our latest technological innovation and the only proven filter that provides common mode reduction, peak voltage protection, and rise time reduction – all in one unit.

SineWave Guardian™ filters (for cable leads up to approximately 15,000 ft.) This best-in-class filter delivers unequaled performance in cleaning the PWM waveforms generated by VFDs. It virtually eliminates high frequency content and voltage peaks, thereby reducing motor heating to provide extended motor life – and less downtime.