Generic selectors
Exact matches only
Search in title
Search in content
Post Type Selectors

Elevating Shaft Grounding: AEGIS Rings at Work in an Ethanol Plant

Aegis
Elevating Shaft Grounding: AEGIS Rings at Work in an Ethanol Plant

Elevating Shaft Grounding: AEGIS Rings at Work in an Ethanol Plant

By: Aegis

During the early months of 2017, at Red Trail Energy‘s ethanol facility in North Dakota, there was a recurring issue with the premature failure of ball bearings in several large motors. Replacing motor bearings isn’t cheap. But for a production plant, the actual cost of repair is a drop in the bottle. What really hurts is the downtime from repair causing lost production. And lost revenue.

The plant manager soon had enough of these frequent interruptions and called in a grounding system specialist to troubleshoot the three problem motors.

Elevating Shaft Grounding: AEGIS Rings at Work in an Ethanol Plant

The plant’s 400 hp HVAC motor

Scott Fisher, at Sustainable Grounding Systems, has a long history with Red Trail Energy. He arrived at the plant in May 2017 and took initial readings from three problematic motors: two centrifuge motors (30 and 150 hp) and one 400 hp fan motor. He confirmed that the bearings in these motors had premature damage, well beyond the expected ordinary wear and tear.

The leading suspect? Stray voltage from variable frequency drives. VFDs cause voltage to build upon the shafts of the motors they control. That voltage tends to discharge through the path of least resistance: the bearings. This shaft voltage discharge causes the bearings to wear, and fail, prematurely.

Fisher’s solution was to install AEGIS® Shaft Grounding Rings. Following AEGIS best practices, he installed an AEGIS SGR on each centrifuge motor, and an AEGIS PRO Ring on the 400 hp motor.

The follow-up shaft voltage readings from the motors showed significant improvement. Measurements as high as 19 volts dropped to less than 1.3 volts, which is too low to cause premature damage to the bearings.

Elevating Shaft Grounding: AEGIS Rings at Work in an Ethanol Plant

Scott Fisher installs an SGR on one of the centrifuge motors

The curious reader might wonder how permanent the AEGIS solution was. It’s a good question! And the good answer is that now, almost four years later, AEGIS is still working. These motors have yet to fail again due to electrical bearing damage. Over the past four years, AEGIS rings have saved this plant tens of thousands, if not hundreds of thousands, of dollars. That’s a pretty good return on investment!

This is adapted from a story published at ChemicalProcessing.com

Related Articles

Related Whitepapers

Building a Centrifugal Pump Digital Twin for a Chemical Plant

A digital twin represents a physical asset and its function; it contains intelligence to evaluate static and real-time data. Chemical refining plants are asset intensive…

Autonomous Fontan pump: Computational feasibility study

A double-inlet, double-outlet rotary pump was designed to augment Fontan flow through the total cavopulmonary connection. Pump power is supplied by a systemic arterial shunt…

Hydraulic design of a centrifugal LOX pump, including cavitation modeling

The study shows the design and optimization of a LOX centrifugal pump with CFturbo/CFturbo BLADERUNNER 2025.R1 for a fictional rocket engine powered by LOX/RP-1, which…

BEP Pump System Optimization Study of a Canola Oil System

Ishwar Dhere, Process Engineer with Stantec Resourcenet India was tasked with analyzing estimated pump head, normal operating line velocities, and pressure analysis for a new…