Rolling element bearing (REB) support is the most recent in a long succession of completed and planned system upgrades. SETPOINT was launched in 2011 with functionality to support basic turbo machinery measurements. Supported machine types were expanded in April 2012 to include hydro-turbines, and again in July 2012 to include large steam turbine-generator sets, reciprocating compressors, and aero-derivative gas turbines.
Rolling element bearings generate vibration frequencies that are governed primarily by bearing geometry. As bearing faults develop, monitoring of the frequency bands that coincide with specific bearing components allows more sensitive monitoring and earlier advanced warning to facilitate maintenance. It also gives insight into root cause of the bearing failure, such as machinery misalignment or unbalance, bearing lubricant breakdown, running hours in excess of L10 life, pitting, spalling, electrostatic discharge, or other causes.
When a channel in the SETPOINT System’s Universal Monitoring Module (UMM) is configured for enveloped acceleration, it now returns the following seven parameters:
- Overall acceleration amplitude
- Enveloped acceleration amplitude, filtered to Outer Race Ball Pass (ORBP) frequency
- Enveloped acceleration amplitude, filtered to Inner Race Ball Pass (IRBP) frequency
- Enveloped acceleration amplitude, filtered to Cage frequency (also known as Fundamental Train Frequency or FTF)
- Enveloped acceleration amplitude, filtered to Ball Spin frequency
- Enveloped acceleration amplitude, filtered to 2X Ball Spin frequency
- Sensor bias voltage
Using bearing tables for the particular bearing geometry, bandpass filter corners for each of the above parameters can be set. Alarms can also be set independently for each parameter. Users can then alarm and trend the vibration levels within these frequency bands for a sophisticated and effective monitoring strategy.
Acceleration enveloping is a widely accepted and field-proven signal conditioning method that allows very low-amplitude signal components to be accurately extracted and isolated from the much larger overall vibration signal. This allows earlier advance warning of bearing degradation and more proactive maintenance planning.
These new measurement capabilities can be enabled in existing hardware in the field by downloading the appropriate firmware and reconfiguring the new channel types as desired.
The SETPOINT system was first announced in October 2010 at the A&M turbomachinery show in Houston. It began shipping to customers in July 2011 and to date has been sold to customers in more than 40 countries. The SETPOINT system features an industry-first integral touchscreen display with intuitive graphics inspired by Apple® iTouch®, iPod®, and iPad® portable devices. The system also eliminates the need for special power supplies by using the 24 Vdc instrument power readily available in most plants, thereby reducing heat in the rack and improving reliability. It introduces innovative front-access wiring connections that make it considerably easier to install and service than rear-access systems. For retrofit applications, its footprint is sized to exactly fit the industry’s most commonly installed systems, ensuring existing cutouts and panels can be reused along with existing wiring.