This article describes a research project we conducted to demonstrate the power of the Verdigris platform. If you're interested in exploring MCSA further, please contact solutions@verdigris.co. 

Verdigris is a high-granularity real-time energy submeter. Using Verdigris you can see symptoms of inefficiency or failure in how a piece of equipment consumes energy up to the minute. Verdigris is different than other energy meters in that it can also identify failing components within inductive motors.

Motors, specifically three-phase induction motors, are the workhorses underpinning components of mechanical equipment. They are critical in the function of compressors, condensers, fans, blowers, elevators, pumps, conveyor belts, and turbines. Inductive motors can be commonly found in large building equipment, such as critical refrigeration systems, conveyance, or production machinery. These machines are present in diverse industries, ranging from Grocery to Life Sciences, to Distribution Centers, to Industrial and Manufacturing.

Verdigris’s uniquely high sampling rate enables us to perform Motor Current Signature Analysis (MCSA). By looking at the electrical current of a piece of equipment we can detect certain motor faults.

A motor fault doesn’t necessarily mean equipment will stop working; however, the motor may become inefficient or closer to complete failure and should be inspected. Because we are looking at electrical signatures in the frequency domain we can often see faults before typical detection systems such as temperature or pressure sensors and long before a motor fails. We notify customers with information early on so there is more time to react and less potential for lost revenue.

Figures. The frequency spectrum of the current from the motor with (above) no broken rotor bars and (below) a broken rotor bar. 

Verdigris also can alert customers when it sees symptoms of mechanical issues, such as short cycling. Short cycling is the rapid turning on and off of a mechanical system, which can occur frequently in air-compressors, furnaces, chillers, and AC units. It can be caused by dirty air filters, an oversized system, or the differential pressure being set too small. This rapid state-change adds unnecessary stress on the system, drastically reducing its lifespan and efficiency. 

Spectrogram (top) and energy (bottom) of a cooling tower. Red marks short-cycling.