With an increase in focus on plant productivity and equipment reliability, SCADA systems are more often being seen as effective tools to reduce downtime while increasing asset reliability in hydraulic systems. A SCADA system is a Supervisory Control and Data Acquisition system: a computer system that essentially gathers and analyzes real time data. These systems not only affect you, but also your customers.
These systems give you the ability to monitor critical sensors and data points, providing you with information on your plant’s network or localized HMI. Having knowledgeable dates and information related to a hydraulic system provides you with key values that help you maintain and protect your assets and improve productivity and reliability.
You can monitor the following elements of your hydraulic power unit with a SCADA system:
- Reservoir temperature
- Fluid contamination/particle counter
- Pressure sensors
- Level sensors
Maintaining a stable temperature within your hydraulic power unit will prolong your unit’s life and improve hydraulic oil health. Over-temperature and under-temperature alarms can be monitored and recorded to provide information about temperature related failures. Cold temperatures can cause cavitation of efficiency losses, and high temperatures can also affect system performance.
How hot is too hot? Hydraulic fluid temperatures above 180°F (82°C) damage most seal compounds and accelerate oil degradation. While you should avoid hydraulic system operations above 180°F in general, fluid temperature is too high when viscosity falls below the optimum value for the hydraulic system’s components, which can occur well below this temperature depending on the fluid’s viscosity grade.
Fluid Contamination/Particle Counter
Most machine and component manufacturers specify a target ISO cleanliness level for equipment, in order to achieve optimal performance. A SCADA system can track and record ISO CODES to provide predictive and proactive equipment failure information related to contamination. Contamination types include:
- New oil: new fluid is not necessarily clean
- Generated contamination: abrasive wear, cavitation wear, fatigue wear, erosive wear and corrosive wear
- External contamination: reservoir breathers, cylinder rod glans and hydraulic hose
Below, you’ll find fluid cleanliness requirements for typical hydraulic components, along with a particle counter that communicates the 4u/6u/14u channels to the SCADA system. By collecting real time ISO codes, you will be able to pinpoint specific system issues or internal maintenance processes that can be improved.
Pressure sensors can be either pressure transducers or pressure switches. Most filters use a DELTA “P” pressure switch, which indicates when it is time to change a filter. A SCADA system can provide a date stamp for when the filter bypass switch has been indicated, and a local user can be notified via local display or network escalation. The ability to monitor the time it takes to change a filter can also provide management and stakeholders with viable information related to maintenance reliability.
Pressure transducers provide analog output to your SCADA system to maintain system performance within a predetermined range. Pressure transducers can also be used for:
- Main system pump pressure: pressure spikes and low pressure can indicate that system calibration is required
- Accumulator pre-charge pressure: pre-charge loss can drastically upset system function, causing equipment failure, loss of production and poor manufacturing quality
Level sensors provide critical information related to system reliability. The minimum level sensor would be a low-level switch, tied to the SCADA system and pump-motor control. This process protects the pump from cavitating and degrading the system in the future. Multiple level switches can also provide you with information related to premature failure.
Level transducers provide additional protection for hydraulic system performance, while providing information about your oil loss. Oil leaks not only raise environmental concerns, but also raise issues concerned with unplanned cleanup and hazardous waste. By having the ability to capture and record proper oil levels, you can protect yourself from unplanned downtime and environmental issues.
Other Areas for SCADA Hydraulic Performance
SCADA systems can also be used in a number of other applications related to your hydraulic power unit. They include:
- Case drains for hydraulic pumps
- Horsepower consumption for prime movers
- Moisture sensors for hydraulic oil, indicating heat exchanger failure
- Suction ball valve switches for pumps
- ITM (Interactive Technical Manual) upgrades
To learn more, contact your local Kaman Fluid Power to speak with a hydraulic specialist today.
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