Show Notes
Power Quality Is a Building Technology Issue
Power quality is easy to overlook because the lights can remain on while critical systems quietly struggle. This episode examines the voltage sags, swells, harmonics, and brief disturbances that can cause access control readers, HVAC controllers, elevator-related systems, and variable frequency drives (VFDs) to reset, fault, or behave unpredictably.
The central point is simple: not every recurring equipment problem is an equipment problem. In a modern building, small disruptions in the electrical supply can look exactly like failed controllers, network issues, bad cabling, or unreliable devices. Replacing components without investigating the power source can create an expensive cycle that never addresses the underlying cause.
Why Modern Buildings Are More Sensitive
Older buildings had fewer electronics connected to operational systems. Today, access control panels, lighting controls, HVAC automation, VFDs, pumps, and other building technologies depend on electronics that can be sensitive to even short power disturbances.
- A power issue does not need to cause a blackout to cause a problem.
- A voltage sag lasting only a few milliseconds may be invisible to people while still disrupting electronics.
- Nonlinear electronics, motors, elevators, and VFDs can contribute to turbulence in the electrical waveform.
- The source of the problem may be inside the building rather than at the utility grid.
The episode compares electrical power to a water supply. If water pressure fluctuates, a facilities team would investigate before pipes burst. Power deserves similar attention. The question is not only whether electricity is present, but whether the electrical feed is stable enough for the building systems that depend on it.
When Dirty Power Looks Like Equipment Failure
Power quality problems are insidious because equipment often does not fail dramatically. There may be no smoke, no obvious outage, and no permanent error code. Instead, a controller may reset itself, a reader may drop offline for 30 seconds, or a VFD may throw a fault that clears before anyone arrives to investigate.
One example in the discussion involved access control readers that went offline every morning on the same floor. The site replaced readers, controllers, and cabling through three rounds of hardware changes, spending thousands of dollars without resolving the issue. A power quality monitor eventually showed that voltage was sagging for a few milliseconds when the elevator began its morning rush. The readers were not defective. The electrical feed was being disturbed by the elevator drive.
The corrective action was not another hardware replacement. It involved service on the elevator drive and adjustments at the electrical panel. The story illustrates a practical lesson for building operators: a recurring issue may be a symptom of a shared power problem, especially when multiple devices experience similar failures.
The Patterns Worth Investigating
A standard multimeter can confirm that voltage is present, but it is not designed to capture a brief three- or five-millisecond voltage sag. Facilities teams need to look beyond a single point-in-time reading when troubleshooting intermittent problems.
- Similar failures across different devices or systems.
- Failures that occur at the same time of day.
- Problems that appear when elevators, chillers, pumps, or other large loads start.
- Issues that become more frequent in certain seasons.
- Faults that clear on their own before a technician can observe them.
- Repeated replacement of equipment that does not solve the problem.
These patterns can point toward the common denominator: the power feeding the affected systems. Rather than treating each failure as isolated, teams should consider whether a shared electrical condition is creating the symptoms.
Start With Data, Not More Parts
Before replacing another controller, reader, or piece of cabling, begin logging the problem. Document when the failure occurred, which systems were affected, and what else was happening in the building at that time. Consider whether a large load was starting, such as an elevator, chiller, or pump.
A week of data can reveal far more than repeated part swapping. A portable power quality monitor can be rented or purchased at a cost that may be far lower than replacing controllers every quarter. For buildings with critical systems, a permanent monitor on the main electrical feed may also be appropriate.
Protect Critical Loads Proportionally
The episode does not recommend putting expensive power conditioning on every outlet. The right investment depends on risk. A $10,000 conditioning solution does not make sense for every low-value device, but the equation changes when a system affects tenant safety, access, or building operations.
- Map the building's critical loads.
- Identify the feeds that support safety-sensitive and operationally essential systems.
- Monitor systems that cannot afford recurring disruption.
- Match protection and monitoring investments to the impact of failure.
Access control may be essential to tenant safety. A breakroom television is not. The goal is to understand what matters operationally and protect those systems in proportion to their risk.
Key Takeaway
Power is the foundation beneath every connected building system. When equipment fails more than once, it is time to stop assuming the device is the problem and investigate the quality of the power feeding it. Better data, targeted monitoring, and risk-based protection can help facilities teams avoid repeat failures, unnecessary replacements, and avoidable operational disruption.
Dirty Power Can Make a Smart Building Act Sick
When building technology starts misbehaving, the usual suspects are familiar: the network, the controller, the cabling, the endpoint, or the software configuration. A badge reader goes offline. An HVAC controller reports communication errors. A variable frequency drive (VFD) faults and then clears. An elevator-related system behaves erratically. Teams begin troubleshooting the visible device because that is where the symptom appears.
But in many modern buildings, the actual problem may be upstream: the quality of the electrical power feeding those systems.
Power quality issues do not always look like an outage. In fact, the most costly problems can occur while the lights stay on and the building appears to be functioning. Short voltage sags, swells, harmonics, and other disturbances can reset sensitive electronics, create intermittent communication failures, and shorten the useful life of equipment. The result is a building that seems to be working, but not reliably.
What “Dirty Power” Means in Practice
Dirty power is not a formal diagnosis for one single fault. It is a practical way to describe electrical conditions that are unstable or unsuitable for sensitive equipment. The episode focuses on voltage sags, swells, harmonics, and turbulence in the electrical waveform.
A voltage sag may last only a few milliseconds. That is far too brief for a person to notice by looking at a light fixture, yet it can be long enough for a controller, access control reader, or VFD to reset or throw a fault. Harmonics and related disturbances can be generated by the nonlinear electronics common in modern facilities. Elevators, VFDs, large motors, pumps, and tenant equipment can also create disturbances that ripple through a building's electrical system.
This matters because buildings now depend on a broad collection of sensitive electronics. Access control, lighting controls, HVAC automation, and equipment control systems all rely on power that is not merely available, but stable.
Why the Problem Is So Often Misdiagnosed
Most troubleshooting processes are built to identify dead equipment, not unhealthy power. If a device is completely failed, standard diagnostic steps may quickly expose the issue. Intermittent problems are different.
A multimeter can show that voltage is present at a panel or outlet. It generally will not capture a voltage drop lasting only three milliseconds when an elevator starts. That difference creates a diagnostic gap. A technician may arrive after the event has passed, find normal voltage, and reasonably focus on the controller, network, or cabling instead.
That is how organizations end up replacing equipment that was never the root cause. The device experiences the failure, so the device gets replaced. When the problem returns, another device gets replaced. The cycle continues because the common cause remains unmeasured.
Look for Failure Patterns, Not Isolated Incidents
A single device failure can be a device problem. Repeated failures across different equipment, however, deserve a wider investigation. The most useful clues are often patterns in time, location, and behavior.
- Do similar devices fail on the same floor or electrical feed?
- Do issues occur at a consistent time of day?
- Do they happen when a known large load starts?
- Do faults clear before a technician can observe them?
- Are different systems showing symptoms that do not initially seem related?
- Have multiple hardware replacements failed to solve the problem?
In the episode, access control readers were dropping offline every morning on the same floor. The site replaced readers, controllers, and cabling through three rounds of hardware changes. The recurring schedule was the clue. A power quality monitor ultimately showed voltage sagging for a few milliseconds when the elevator entered its morning rush. The power disturbance, not the readers, was the issue.
Resolving the problem required service on the elevator drive and adjustments at the panel. The case reinforces an important operational lesson: when failures repeat on a pattern, investigate the shared environment before replacing more endpoints.
Why Poor Power Quality Creates Long-Term Cost
Not every consequence of poor power quality is an immediate outage. Electronics can continue working while being subjected to conditions that cause instability or faster degradation. This is similar to a car running rough: it may still get where it needs to go, but the underlying condition can reduce the life of the engine.
For a building, that means premature failures that appear random. A controller may fail earlier than expected. A reader may intermittently lose connectivity. A drive may produce a recurring fault code. Each incident can look unrelated when viewed separately, yet all may be connected to the same electrical condition.
The direct replacement cost is only part of the impact. Facilities teams also lose time coordinating vendors, dispatching technicians, investigating alerts, and explaining disruptions to tenants. Systems supporting access, safety, and daily operations can create additional business risk when they become unreliable.
Use Monitoring to Replace Guesswork With Evidence
The first practical step is to log the problem before replacing more hardware. Record the time of each incident, affected systems, and building activity occurring at the same time. Note whether elevators, pumps, chillers, or other large loads were starting or changing operating state.
That record gives a power quality specialist or facilities contractor something concrete to investigate. It also helps distinguish a one-time device issue from a recurring electrical pattern.
A portable power quality monitor can capture disturbances that normal spot checks miss. The episode recommends gathering about a week of data rather than relying on a guess. For critical buildings and systems, a permanent monitor on the main feed may be appropriate. The decision should be based on operational importance, not on a blanket rule that every electrical circuit needs the same level of protection.
Protect What Matters Most
Effective power-quality strategy is risk-based. A building does not need a costly conditioning system for every outlet, and not every device warrants the same investment. The question is which loads are essential to tenant safety, building operations, and business continuity.
Access control may protect tenant safety and secure areas of a building. HVAC controls may support comfort and operations. Systems that repeatedly disrupt those functions deserve greater attention than low-impact equipment such as a breakroom television.
Start by mapping critical loads. Identify the electrical feeds that support essential systems, monitor those feeds, and apply protection proportionally. This approach keeps technology aligned with the operational outcome it is meant to support: a building that works predictably for the people who rely on it.
Make Power Quality Part of Building Operations
Power quality should be treated as foundational infrastructure, not as an afterthought reserved for major outages. The electrical feed supports every connected system above it. When that foundation is unstable, the effects can surface in access control, HVAC, lighting controls, and other technologies that appear unrelated.
The next time a critical device fails for a second time, pause before approving another replacement. Look at the timing. Look at other systems. Look at major loads. Then collect the data needed to determine whether the equipment is truly defective or whether the power feeding it is the problem.
For more practical discussion on building technology, operational risk, and infrastructure decisions, listen to this episode of Built, Wired & Secured.