Any industrial automation system would have dozens of devices such as PLCs and HMIs, and servo drives and relays, which would all depend on one vital element for their proper functioning. That is the stable power supply. While automation devices have been growing rapidly in the last few years, the PSU that powers such devices has been going almost unnoticed.
Power supplies, in general, are over time exposed to the following things: electrical stress, temperature changes, vibration, dust, and environmental pollution. These factors combine to gradually break down the internal components of the power supply hence it becomes less and less capable of providing a stable voltage supply. This is what is known as power supply aging, and it is slowly becoming a significant issue in the field of modern automation technology.
This blog will investigate the reasons why biofilm formation causes PSU aging, the PSU that impacts industrial systems, warning signs, and how facilities can lessen the potential of high failure costs.
What Causes Power Supply Aging?
In the end, these power sources will be judged failures caused by nature (environmental factors around them), the stress under which they will be used (due to their intended usage) and the wear and tear of their components. By figuring out the reasons behind the power supply failure, it will be possible to predict the breakdown before the time the machine will stop. Among the reasons leading to power supply failure due to aging are the following factors:
1. Wear-Out of Electroly
An electrolytic capacitor in a power supply is the one that basically performs the filtering functions and is the one that guarantees a stable output voltage by noise suppression in the power supply. The electrolyte in those capacitors is something that keeps evaporating with time, especially if the heat caused by the ripple current is still there. Hence the capacitance of these capacitors decreases as the resistance increases due to evaporation.
- More ripple output
- Slow voltage response
- Increased heat generation
- Sudden or Intermittent PSU Failure
It is considered the major factor that most frequently and inevitably accounts for the aging of industrial power supplies.
2. Thermal Stress (Continuous)
By far, the most harmful factor for electronic components of any kind is heat. In most cases, power supplies are the ones that generate the heat in a closed cabinet where drives, controllers, and transformers are placed around them—a typical scenario for overheating.
How thermal stress speeds up aging:
- It weakens capacitor electrolyte
- Reduces the life span of the switching transistors
- Degraded solder joints
- Degrades insulation of internal wiring
Just a 10° C increase over the rated temperature can reduce the PSU lifespan by nearly half. Poor ventilation and cooling fans that are not working only aggravate this problem.
3. Electrical Noise and Surges
Industrial environments are full of different types of electric disturbances that could be caused by motors, welding sets, heavy load switching, and unstable power supplies. Disturbances like these are made up of:
- Voltage spikes
- Harmonics
- High-frequency noise
- Transient surges
Such situations put a lot of pressure on the rectifiers, the MOS FETs, and the capacitors in the power supply. Over time, the insulation wears out, the switch components change, and the
This makes the power supply bad in terms of reliability as it shuts down randomly.
4. Dust, Moisture & Vibration
The most significant causes of the power supply unit to fail are the environment-related ones.
Dust:
Particles of dust work as an insulator, they trap heat, and thus the temperature rise in the place where the dust is deposited on the PCB.
Humidity:
It is the main cause of corrosion of the terminals and tracks, which eventually results in short circuit or even more, in the case of poor conductivity.
Vibration:
It is the main reason for the loosening of connectors and solder joints already found in marine and heavy machinery environments.
When working together, these elements reduce the lifespan of the PSU and increase the number of intermittent faults.
5. Long Operational Life
Power supplies for industrial use operate constantly: day and night, year after year. This means their internal parts wear out just like their mechanical counterparts.
Effects caused by long working hours:
- Capacitors lose capacitance.
- Switching components fatigue
- Fans wear out
- Base material for PCBs is adversely affected by thermal cycling
A high-quality power supply is not meant to last an eternity. After 5-10 year periods, the power supply starts showing signs of aging, particularly in an automation environment.
Why Aging Power Supplies Are a Growing Concern in Automation
As a result of more complex systems being used to achieve higher levels of automation, the power supply that feeds those systems is becoming the most crucial element. Old power supplies are not only a drag on efficiency, but they also pose risks at the system level that can lead a whole operation to stop abruptly.
These are the main reasons why old PSUs have become the most perilous factors of modern automation.
1. Modern Automation Devices Are Voltage-Sensitive
Today's automation technology, including PLCs, HMIs, servo drives, VFDs, sensors, and SCADAs, is very sensitive to even the smallest voltage change. Slight deviation, voltage spike, or voltage ripple will only result in the automation systems' malfunctioning.
Why this matters:
- PLCs may reboot on their own
- Servo Drives May throw Overcurrent or Encoder Errors
- It can be caused by different factors, and sensors
- Communication modules may be detached
Power supplies will gradually become unable to provide stability for the machine's volts as they age. The reason for that is with aged power supplies, components will fail, and this will cause the machine to behave unpredictably when connected to this source. Electronics have become very sensitive; therefore, PSU stability has never been as important as it is today.
2. Downtime Costs Are Higher Today
When the automated lines are designed for maximum efficiency. The loss of a few minutes of productivity can cause a huge loss of money, especially in the following areas:
- Manufacturing plants.
- Food Processing Lines
- Packaging Industries
- Marine and offshore operations
- Manufacturing of pharmaceuticals
Most of the time, the power supply unit that has been ailing for a long will upon its failure, make the whole power off all the devices that are connected to it simultaneously, thus leading to:
- Lost batches
- Delays in Shipment
- Labor inefficiency
- Rework and scrap
As machine interconnectivity has been implemented, a single PSU can thus cause several machine systems to be down, instead of only one machine that is affected. Therefore, PSU maintenance is considered the most important maintenance activity at present.
3. More Electrification of a Plant = More Dependency on Power
Presently, automated systems are progressively electrified in their components:
- Servo systems
- Smart Sensors
- High-speed communication
- Internet of Things gateway
- AI-based monitoring
- Digital safety systems
All these require a clean and stable DC power supply. If one power supply is old, it can be unable to provide clean voltage to many devices and result in a power failure.
Consequences include:
- Communications that are not recorded
- Interruptions of the network
- Faults in the PLC modules
- The Safety relay malfunctions
With the trend of digitalization going up, a power supply that is not reliable should not be just a minor problem but a possible impaction of the whole automation chain.
4. PSU Failures Are Often Misdiagnosed
One of the biggest issues with power supplies, in general, is that they can be really tricky when it comes to their aging. An instance is when a power supply doesn't fail all at once but rather decomposes slowly and thus its symptoms looks like something unrelated to power.
Common misdiagnoses:
- Installing new sensors when the old ones seem to be defective or faulty.
- Changing PLC programs without need
- Changing servo drives or motors
- Wires and communication paths checking continuously
In a case where PSU problems are the actual source of instability, replacing components will not solve the issue. That impacts:
- Time is wasted
- Repair charges are getting higher
- More downtime
- Equipment failures
Early detection of the PSU aging process can be a great help in saving operational time and also in avoiding the time-consuming and inefficient method of troubleshooting.
When Should You Replace an Old Power Supply?
Replace the PSU if you notice:
- Repeated drive or PLC faults
- Unstable analog readings
- Overheating
- Fan failure
- Output voltage drifting
- Ripple noise increasing
- Age above 7 years in harsh environments
Power supply deterioration is a major contributing factor to the rising number of issues in automation technology that is leading to failures of entire systems are becoming very common. One of the main reasons for this is that all components such as PLCs, HMIs, servo drives, VFDs, sensors, and communication modules need clean and stable voltage supply to perform their functions properly. Over time, the failure of the power supply’s internal components like drying of electrolytic capacitors, intensified thermal stress, and the breakdown of switching elements leads to the power supply losing its voltage regulation capability.
Aged power supplies significantly impact automation systems by causing them to behave erratically, restart automatically, and sensors to provide faulty data as well as communication between various devices ceasing. The main reason for this situation is that modern devices have become very sensitive to voltage changes, and the value of lost production time is much higher than it used to be; therefore, even a minor deviation in the power supply can cause considerable losses in production. In addition, the problem may look like different malfunctions such as faulty sensors or drives.
First of power supply voltage drift, ripple, overheating, fan failure, or recurring equipment failure detection, and then power supply replacement every 5 to 10 years prevent the most expensive failure. The importance of the condition of the power supply for the machines as the level of digitalization in the machines is continuously rising is one of the factors that contribute to the safe, efficient, and troublefree operation of the automation systems.
