Why Power Supply Aging Is Becoming a Serious Issue in Automation
Why Power Supply Aging Is Becoming a Serious Issue in Automation
Modern industrial automation systems are built to operate reliably for years.
PLCs control processes. HMIs provide operators with critical information. Sensors continuously measure field conditions. I/O modules connect the control system to the plant floor. VFDs regulate motors and equipment.
When all these components work together, the system can appear almost effortless.
But there is one part of the automation system that is often overlooked until something goes wrong:
The power supply.
A power supply may not have the visibility of a PLC or the complexity of a SCADA system, but it provides the electrical foundation that allows many control components to operate correctly.
As industrial facilities in the UAE continue to operate automation systems around the clock, aging power supplies are becoming a maintenance concern that should not be ignored.
At CMETS, as an Industrial Automation Specialist in the UAE, we have seen how apparently unrelated automation problems can sometimes be traced back to the quality and condition of the power supplying the control system.
A PLC that randomly restarts.
An HMI that suddenly goes blank.
A sensor that intermittently loses its signal.
An I/O module that starts reporting faults.
A VFD that experiences communication errors.
These symptoms can lead engineers toward complicated software, networking or controller-related investigations when the underlying issue may be much simpler:
Unstable or deteriorating power.
CMETS supports industrial automation across sectors including oil & gas, utilities, water treatment, marine, manufacturing and other industrial environments, providing PLC, SCADA, HMI, RTU and switchgear engineering, installation, commissioning and maintenance services.
Why Power Supply Aging Matters in Industrial Automation
Industrial power supplies are not immune to aging.
Like other electrical and electronic equipment, their performance can deteriorate over time due to operating temperature, electrical stress, loading, environmental conditions and component degradation.
The problem is that a failing power supply does not always fail completely.
In many industrial situations, degradation happens gradually.
The power supply may continue producing approximately the expected voltage under light conditions but struggle when the connected equipment demands more current.
Ripple or electrical noise may increase.
Internal components may operate at higher temperatures.
Output voltage may become less stable.
The result can be intermittent automation problems that are difficult to reproduce.
This is what makes aging power supplies particularly dangerous from a maintenance perspective.
Why UAE Industrial Environments Can Accelerate Power Supply Problems
The UAE presents some demanding operating conditions for industrial electrical and automation equipment.
CMETS works across industries including oil & gas, power and utilities, water and wastewater, district cooling and HVAC, manufacturing, steel, aluminium, mining, food and beverage, pharmaceuticals and other industrial sectors.
In these environments, automation equipment can operate continuously while being exposed to demanding electrical and environmental conditions.
Several factors can contribute to premature power-supply degradation.
1. High Ambient Temperatures
Heat is one of the most important environmental considerations for electronic equipment.
Industrial control panels located in hot environments may experience elevated internal temperatures, particularly when ventilation or cooling is inadequate.
Continuous exposure to higher temperatures can accelerate the aging of electronic components.
This is particularly relevant in the UAE, where panel temperature management needs to be considered during design, installation and maintenance.
A power supply operating continuously in a hot enclosure may experience considerably more thermal stress than the same equipment operating in a properly cooled environment.
Heat management is therefore not simply a comfort issue for the panel it is part of equipment reliability.
2. Dust and Poor Ventilation
Industrial environments can expose control panels to dust and airborne contaminants.
When ventilation paths become restricted or panel cooling is inadequate, heat can accumulate.
Dust can also contribute to contamination and reduce the effectiveness of cooling arrangements.
Regular inspection and appropriate panel maintenance can help prevent these conditions from becoming long-term reliability problems.
3. Voltage Fluctuations
Industrial facilities can experience variations in incoming electrical supply.
If the input to a power supply is unstable, the power supply itself has to operate through those variations.
Repeated electrical stress can contribute to premature deterioration and may also create instability in connected automation equipment.
For this reason, checking only the nominal input voltage is not always sufficient.
The actual behavior of the supply should be understood over operating conditions.
4. Electrical Surges and Transients
Electrical transients can originate from switching events, inductive loads, motors and other equipment within an industrial electrical system.
Sensitive automation electronics can be affected by poor power quality.
Appropriate surge protection and proper electrical design can help reduce exposure to these events.
5. Continuous 24/7 Operation
Many industrial facilities are not switched off every evening.
Their automation systems may operate continuously for months or years.
A power supply running continuously under load experiences ongoing thermal and electrical stress.
This is one reason preventive maintenance becomes particularly important in critical automation systems.
6. Overloading
A power supply operating close to its maximum rated capacity leaves less margin for changing load conditions.
As additional devices are added to a control panel over time, the original power-supply capacity may no longer provide an appropriate operating margin.
This can happen gradually.
A system may start with a reasonable load and later accumulate additional:
- Sensors
- Relays
- Solenoid valves
- Communication devices
- I/O modules
- HMIs
- Other control components
The result can be a power supply that is technically operating within its nominal specifications but has very little practical headroom.
7. Poor-Quality Power Supplies
The cheapest component is not always the lowest-cost solution over the life of an industrial system.
An unreliable power supply can create troubleshooting time, unplanned downtime and secondary equipment problems.
For critical automation applications, reliability, suitability, operating conditions and technical support should be considered alongside purchase price.
8. Loose or Poor Connections
Not every “power supply problem” originates inside the power supply.
Loose terminals, poor connections, damaged wiring or inadequate termination can introduce voltage drops and intermittent faults.
That is why physical inspection remains an important part of troubleshooting.
What Happens When an Industrial Power Supply Starts Aging?
The most difficult part of power-supply aging is that the symptoms can look like problems elsewhere in the automation system.
For example, an engineer may initially suspect:
- PLC hardware
- PLC software
- Communication networks
- VFDs
- Sensors
- I/O modules
- HMI hardware
- Industrial Ethernet
- Field wiring
Sometimes those components are genuinely responsible.
But sometimes the common factor is the power supply.
An aging supply can create an unstable electrical environment that affects multiple devices simultaneously.
This is why looking at the system as a whole is important.
Warning Signs of an Aging 24V DC Power Supply
Based on the types of problems encountered in industrial automation environments, engineers should pay attention to several warning signs.
PLCs Randomly Restarting
A PLC should not randomly reboot during normal operation.
If unexplained PLC restarts begin occurring, the power supply should be part of the investigation.
Do not automatically assume the PLC itself has failed.
Check the power feeding it.
HMI Screens Going Blank or Rebooting
An HMI that suddenly turns off or restarts can be caused by several issues.
Power stability should be one of the checks.
If the HMI and other control components are experiencing intermittent behavior, examining the common power source can be especially useful.
Sensors Intermittently Losing Signals
A sensor may appear to be defective when the real problem is unstable supply voltage or poor connections.
Intermittent faults are particularly difficult because the system may work normally when the technician arrives.
I/O Module Faults
Unexpected I/O faults can result from various causes, including wiring, configuration, module problems and power instability.
Again, checking the power supply helps eliminate one important potential cause.
VFD Communication Errors
Communication errors are often associated with networking or configuration issues.
However, if a VFD or related control equipment is experiencing unstable power, communication behavior may also become unreliable.
The key is not to assume the network is automatically responsible.
24V DC Voltage Dropping Under Load
This is one of the most important warning signs.
A power supply may show an acceptable output voltage when checked without the full operating load but experience a drop when the connected equipment is operating.
This is why testing under actual load matters.
Increasing Ripple or Noise
A deteriorating power supply may exhibit increased electrical ripple or noise.
For sensitive control electronics, power quality matters.
If the system is showing unexplained intermittent behavior, checking ripple/noise can provide useful diagnostic information.
Power-Supply Overheating
Excessive temperature should never be ignored.
Overheating can indicate:
- Excessive loading
- Poor ventilation
- High ambient temperature
- Internal degradation
- Installation issues
A hot power supply deserves investigation before it becomes a failure.
Unexplained Automation Alarms
Not every alarm points directly to its root cause.
If multiple unrelated alarms begin appearing intermittently, engineers should look for common dependencies.
Power is one of those dependencies.
How to Troubleshoot an Aging Power Supply
At CMETS, a practical troubleshooting process starts with basic electrical checks before moving toward more complex investigations.
Our recommended sequence is:
Step 1: Measure the 24V DC Output Voltage
Start with the power supply output.
Verify whether the actual DC voltage is within the appropriate operating range for the connected equipment.
Do not rely only on what the power supply display or specification says.
Measure it.
Step 2: Check Voltage Under Actual Load
This is critical.
A supply can appear healthy under light or no-load conditions and behave differently when the connected equipment is operating.
Measure the output under the actual operating load.
If voltage falls significantly when the system is loaded, investigate the power supply capacity, loading, wiring and connections.
Step 3: Check AC Input Voltage and Fluctuation
The power supply cannot be evaluated properly without understanding what is happening on its input.
Check the incoming AC supply and look for abnormal fluctuation or disturbances.
This can help determine whether the issue originates upstream.
Step 4: Inspect Temperature and Ventilation
Check:
- Panel temperature
- Power-supply temperature
- Ventilation openings
- Cooling arrangements
- Fan operation where applicable
- Dust accumulation
- Panel layout
A power supply installed in a hot, poorly ventilated enclosure may experience unnecessary thermal stress.
Step 5: Check Ripple and Noise
If intermittent control problems continue without an obvious cause, evaluate output ripple/noise using appropriate test equipment and procedures.
This is particularly useful when the DC voltage appears acceptable but sensitive automation equipment continues to behave unpredictably.
Step 6: Inspect Terminals and Connections
Finally, inspect the physical installation.
Look for:
- Loose terminals
- Poor crimps
- Damaged conductors
- Discoloration
- Corrosion
- Poor termination
- Loose DC distribution connections
A small connection problem can create a surprisingly large troubleshooting challenge.
Power Supply Aging Can Become a Hidden Maintenance Problem
A completely failed power supply is relatively easy to diagnose.
The system stops.
The engineer checks the panel.
The failed component is identified.
It is replaced.
The system restarts.
An aging power supply is more complicated.
It may work for several hours.
Then the PLC restarts.
The system operates normally again.
Later, the HMI reboots.
Then a sensor loses its signal.
Then a VFD communication alarm appears.
The maintenance team may spend hours investigating each symptom separately.
This can increase troubleshooting time and potentially lead to unnecessary component replacement.
A more effective approach is to look for common causes.
When multiple automation components begin behaving unpredictably, investigate their common power source.
How to Prevent Premature Power Supply Aging
Preventive maintenance is generally more effective than waiting for a critical automation component to fail.
Select the Correct Power Supply
Choose a power supply appropriate for:
- Required voltage
- Required current
- Environmental conditions
- Installation location
- Operating temperature
- Expected duty cycle
- Load characteristics
Do not size the supply based only on today’s minimum load.
Consider future expansion and appropriate operating margin.
Avoid Continuous Operation at Maximum Capacity
If the power supply constantly operates near its limit, the available margin becomes smaller.
A properly engineered system should consider the real operating load and expected future additions.
Maintain Panel Ventilation
Keep ventilation and cooling arrangements functional.
Inspect filters, fans and ventilation paths where applicable.
Don’t allow dust accumulation to become a thermal problem.
Monitor Critical Power Supplies
For critical automation systems, periodic checks can help identify degradation before a failure causes downtime.
Depending on the application, maintenance teams can monitor:
- DC output voltage
- Input voltage
- Temperature
- Load
- Ripple/noise
- Connection condition
Inspect Connections During Preventive Maintenance
Do not limit preventive maintenance to the automation software.
Physical electrical connections matter.
Terminal inspections should form part of appropriate maintenance procedures.
Protect Against Electrical Disturbances
Where required by the electrical design, appropriate surge protection and power-quality measures should be considered.
The objective is to reduce unnecessary stress on sensitive automation equipment.
A Practical Power Supply Health-Check Framework
For industrial maintenance teams, a simple framework can help:
INPUT → POWER SUPPLY → LOAD → ENVIRONMENT → CONNECTIONS → SYMPTOMS
INPUT
Is the incoming AC supply stable?
POWER SUPPLY
Is the DC output stable and appropriate?
LOAD
Is the supply appropriately sized and operating within its intended capacity?
ENVIRONMENT
Is heat, dust or poor ventilation affecting the equipment?
CONNECTIONS
Are terminals and wiring secure?
SYMPTOMS
What equipment is actually experiencing the problem?
This approach prevents technicians from immediately replacing expensive PLCs, VFDs or communication equipment without first checking the power foundation.
Common Mistakes When Troubleshooting Automation Power Problems
Mistake 1: Immediately Replacing the PLC
A PLC restart does not automatically mean the PLC is defective.
Check the power feeding the PLC first.
Mistake 2: Checking Voltage Without Load
A no-load or light-load measurement may not reveal a problem that appears during actual operation.
Mistake 3: Ignoring the Environment
A power supply installed in a hot, dusty or poorly ventilated enclosure may experience conditions very different from those assumed during design.
Mistake 4: Blaming the Network for Every VFD Communication Error
Communication problems can have many causes.
Power stability should not be overlooked when troubleshooting intermittent communication issu
Mistake 5: Ignoring Connections
Loose or poor connections can create intermittent problems that are extremely difficult to reproduce.
Mistake 6: Waiting Until Complete Failure
A power supply that is already showing warning signs should not necessarily be left until it fails completely especially when it supports a critical control system.
Mistake 7: Focusing Only on Component Replacement
Replacing a component may temporarily solve a symptom without addressing the underlying cause.
If excessive heat, overloading or voltage disturbances remain, the replacement component may eventually experience the same problem.
The UAE Industrial Perspective: Reliability Matters More Than Ever
Industrial facilities in the UAE increasingly depend on automation for operational efficiency, safety and process visibility.
CMETS provides automation solutions across sectors including oil & gas, utilities, water treatment, marine and other industrial environments, with capabilities covering PLC, SCADA, HMI, RTU and switchgear systems.
CMETS also describes its engineering approach across assessment/design, software configuration, installation and commissioning, supporting the need to consider reliability across the lifecycle rather than only during initial installation.
This lifecycle perspective is important.
An automation system is not finished when it is commissioned.
It needs to remain reliable years after commissioning.
That means maintenance teams should think about aging components—not just failed components.
A Contrarian View: The Most Dangerous Power Supply Is Not Always the One That Has Failed
A completely dead power supply gets attention immediately.
An aging power supply that still works can be more difficult.
Why?
Because it can create intermittent problems.
Intermittent problems consume engineering time.
They create uncertainty.
They may result in repeated troubleshooting.
And because the equipment sometimes works normally, the root cause can be difficult to reproduce.
This leads to an important maintenance principle:
Don’t wait for the power supply to completely fail before considering its condition.
If a critical control system has an aging power supply and is already showing warning signs, investigate the situation proactively.
How CMETS Supports Industrial Automation in the UAE
CMETS Energy Solutions is headquartered in Abu Dhabi and provides engineering, automation and system-integration services across the UAE and wider region. The company states that its industrial automation division delivers PLC, SCADA, HMI, RTU and switchgear solutions, covering design, programming, installation, commissioning and maintenance.
Its automation expertise supports industries including:
- Oil & Gas
- Power and utilities
- Water and wastewater
- Manufacturing
- Marine
- District cooling and HVAC
- Steel and aluminium
- Food and beverage
- Pharmaceuticals
- Renewable and green-energy applications
CMETS also emphasizes long-term relationships with global technology partners and engineering support for complex industrial environments.
For companies experiencing recurring PLC, HMI, I/O or VFD-related issues, a structured investigation of the automation power infrastructure can help identify whether power stability is contributing to the problem.
Power supplies rarely receive the same attention as PLCs, VFDs, SCADA systems or HMIs.
But they are fundamental to the reliable operation of many automation systems.
As industrial facilities operate for longer periods, add more equipment and face demanding environmental and electrical conditions, power-supply aging deserves greater attention.
The important lesson is simple:
Don’t wait for the power supply to fail completely.
Watch for the warning signs.
A PLC that randomly restarts.
An HMI that reboots.
A sensor that intermittently loses its signal.
An I/O module that reports unexplained faults.
A VFD that experiences communication errors.
A 24V DC output that drops under load.
Increasing ripple or noise.
Overheating.
Unexplained alarms.
And in an industry where every unexpected shutdown can affect productivity, safety and operational continuity, power-supply health should be treated as part of the automation maintenance strategy not an afterthought.
Frequently Asked Question
Why industrial power do supplies age?
Industrial power supplies can degrade over time because of continuous operation, thermal stress, electrical loading, voltage fluctuations, electrical transients, environmental conditions and component aging.
What are the signs of a failing 24V DC power supply?
Common warning signs can include PLC restarts, HMI reboots, intermittent sensor signals, I/O faults, VFD communication errors, output-voltage drops under load, increased ripple/noise, overheating and unexplained automation alarms.
Can a bad power supply cause PLC restarts?
Yes. An unstable or deteriorating power supply can be one possible cause of PLC restarts. However, PLC hardware, wiring, grounding, software and other electrical issues should also be investigated.
Why should 24V DC voltage be checked under load?
A power supply may show an acceptable voltage when lightly loaded but experience a voltage drop when the connected automation equipment operates under its actual load. Load testing therefore provides more useful information than a single no-load measurement.
Can heat affect industrial power supplies?
Yes. High operating temperatures can increase thermal stress on electronic components and may contribute to premature degradation. Proper enclosure ventilation and thermal management are therefore important.
Should old power supplies be replaced even if they still work?
Not necessarily in every application. Replacement decisions should consider equipment age, criticality, operating conditions, measured performance, maintenance history, loading and the consequences of failure. For critical systems showing warning signs, proactive assessment and replacement planning can reduce the risk of unexpected downtime.
How can industrial facilities prevent power-supply failures?
Facilities can reduce risk through appropriate power-supply sizing, adequate load margin, environmental control, preventive maintenance, voltage and load checks, and inspection of connections, appropriate surge protection and monitoring of warning signs.