Introduction Modern industrial robots are remarkable machines. A six-axis welding robot can repeat the same motion to within fractions of a millimeter, thousands of times per day, for years on end. Collaborative robots work alongside human operators with force-sensing precision measured in newtons. Vision-guided assembly systems make real-time adjustments at speeds no human technician could […]
Modern industrial robots are remarkable machines. A six-axis welding robot can repeat the same motion to within fractions of a millimeter, thousands of times per day, for years on end. Collaborative robots work alongside human operators with force-sensing precision measured in newtons. Vision-guided assembly systems make real-time adjustments at speeds no human technician could match.
What these systems share, beyond their mechanical sophistication, is an acute sensitivity to the quality of the electrical power they receive.
Power quality problems that a standard induction motor might tolerate without complaint — a brief voltage sag, a harmonic spike, a momentary interruption — can halt a robotic production line, corrupt a motion controller’s memory, damage servo drive components, or trigger safety shutdowns that take hours to diagnose and reset. In a Southeast Michigan automotive stamping plant, a West Michigan food processing facility running continuous production, or a Grand Rapids medical device manufacturer operating under validation requirements, a power quality event that stops the robots stops the line.
This guide explains what power quality means in the context of industrial robotics, what the relevant standards require, what problems Michigan manufacturers commonly encounter, and what infrastructure investments protect robotic systems from power-related failures.
Power quality refers to the characteristics of the electrical supply delivered to equipment — and how closely those characteristics match what the equipment was designed to receive. For industrial robotics, the relevant parameters are more demanding than for most other industrial equipment.
Industrial robots and their associated servo drives, motion controllers, and programmable logic controllers are designed to operate within a specific voltage range — typically ±10% of nominal. Within that window, most systems compensate automatically. Outside it, problems begin.
Voltage sags — brief reductions in supply voltage lasting from a half-cycle to several seconds — are among the most common power quality events in industrial facilities. They’re typically caused by large motor starts, welding operations, or faults on the utility grid. For a robot controller receiving a voltage sag below its tolerance threshold, the result may be a nuisance trip, a controlled shutdown, or in some cases a fault that requires manual reset and re-homing of the robot’s position reference.
Voltage swells — brief overvoltages — are less common but can damage sensitive electronic components in servo drives and controllers if they exceed equipment ratings.
Voltage imbalance across three-phase supply can cause thermal stress in robot drive motors and reduce service life, even when individual phase voltages appear within specification.
Most industrial robot controllers are designed for 60 Hz supply with a tolerance of ±2 Hz or tighter. Frequency deviations outside this range — uncommon on the utility grid under normal conditions but possible during generator operation or grid disturbances — can cause controller timing errors, communication faults, and servo synchronization issues. This is a particular consideration when transitioning from utility power to generator backup: if the generator’s governor response is slow or its frequency regulation is imprecise, the transition can cause robot faults even if the transfer switch operates correctly.
Harmonic distortion — the presence of voltage or current components at frequencies that are multiples of the fundamental 60 Hz — is increasingly common in facilities with large numbers of variable frequency drives (VFDs), rectifiers, and switching power supplies. Robots themselves contribute to harmonic distortion through their servo drive systems. When multiple robots operate in close proximity on a shared electrical distribution system, the cumulative harmonic load can exceed the tolerance thresholds of the most sensitive equipment on the circuit.
IEEE 519 establishes recommended limits for harmonic distortion in industrial power systems. The standard distinguishes between current distortion (the responsibility of the equipment connected to the system) and voltage distortion (a characteristic of the system itself). For most industrial facilities, the voltage total harmonic distortion (THD) limit at the point of common coupling is 5% under IEEE 519. Robotic systems with particularly sensitive control electronics may require tighter limits at the equipment terminals.
Transients — brief, high-energy voltage spikes lasting microseconds to milliseconds — can corrupt data in robot controllers, damage power supply components, and cause spurious fault conditions. They’re typically caused by lightning, capacitor switching, or electrical faults on the distribution system.
Complete power interruptions, even momentary ones measured in cycles, typically trigger robot safety systems that require controlled restart procedures before production can resume. In facilities with significant changeover complexity, a single momentary interruption can cost 30 minutes or more of recovery time.
Several standards govern power quality in industrial environments hosting robotics:
IEEE 519-2022 — the primary U.S. standard for harmonic control in electric power systems — establishes voltage and current distortion limits at the point of common coupling between the utility and the facility. It defines limits based on the ratio of short-circuit capacity to load current (the stiffer the system, the tighter the limits for larger customers).
SEMI F47 — originally developed for semiconductor manufacturing equipment — defines voltage sag immunity requirements that have become widely adopted for industrial automation equipment beyond semiconductors. It specifies that equipment must ride through voltage sags to 50% of nominal for up to 200 milliseconds, and sags to 70% for up to 0.5 seconds, without tripping or faulting. Many robot manufacturers cite SEMI F47 compliance in their specifications; facilities managers should verify which components in a robotic cell meet this standard and which do not.
IEC 61000-4 series — the international electromagnetic compatibility (EMC) immunity standards — establishes test levels for equipment immunity to voltage dips, short interruptions, voltage variations, and conducted disturbances. Robot manufacturers typically specify their equipment’s compliance with relevant IEC 61000-4 levels; understanding those ratings helps facilities engineers determine where additional power conditioning is warranted.
NFPA 70 (National Electrical Code) Article 647 — covers sensitive electronic equipment and establishes wiring requirements for circuits serving equipment with critical power quality needs, including grounding requirements that affect noise susceptibility.
Understanding which standards apply to your specific robotic equipment — and where your facility’s power supply currently falls relative to those standards — is the starting point for any power quality improvement project.
Michigan manufacturing environments present several recurring power quality challenges that facilities engineers and maintenance managers encounter with robotic systems.
Michigan’s utility infrastructure, served primarily by DTE Energy (covering Metro Detroit, Ann Arbor, and much of Southeast Michigan) and Consumers Energy (serving West Michigan, Mid-Michigan, and the Upper Peninsula), is subject to weather-related disturbances that can cause voltage sags and momentary interruptions. Ice storms — a recurring feature of Michigan winters — cause distribution faults that result in voltage sags even at facilities that don’t lose power entirely. Spring and summer severe weather brings similar exposure. Facilities in rural areas of Northern Michigan and the Upper Peninsula—including manufacturing plants in Marquette County, Chippewa County, and Gogebic County—are served by longer distribution lines and typically see higher exposure to weather-related power quality events than Metro Detroit, Grand Rapids, Lansing, or Kalamazoo facilities fed from denser urban infrastructure.
Large stamping presses, resistance welding equipment, large air compressors, and HVAC equipment with large motor loads create voltage sags on the facility’s internal distribution system when they start or cycle. In older facilities where the electrical distribution infrastructure was designed before the current robotics load was installed, these internally generated sags may be more severe than what the utility delivers, and they occur far more frequently.
Michigan automotive and manufacturing facilities often operate dense populations of VFDs — on conveyors, machine tools, HVAC systems, and the robots themselves. Without harmonic mitigation, the cumulative THD in these facilities can significantly exceed IEEE 519 limits, creating voltage distortion that degrades robot controller performance and reduces drive component service life.
Facilities that rely on standby generators for backup power face a specific power quality challenge at the moment of transfer. The transition from utility to generator power, even with a fast automatic transfer switch, involves a brief interruption. More critically, if the generator’s output frequency or voltage is not within tight tolerances when the transfer occurs, the robots may see a power quality event at the moment the backup power comes online — the exact moment when reliable power is most critical.
Several infrastructure approaches address power quality for robotic manufacturing environments, typically in combination.
A UPS installed upstream of robot controllers and programmable logic controllers provides ride-through capability for short interruptions and voltage sags. Double-conversion UPS systems, which continuously power the load from an inverter, provide the cleanest power isolation — the connected equipment sees a regulated, conditioned output regardless of what the input supply is doing. For robotic applications, double-conversion UPS is generally preferred over line-interactive or standby designs because it provides true voltage and frequency regulation, not just sag mitigation.
The practical limitation of UPS systems is runtime — most facility UPS installations are sized for minutes, not hours. Their role is to bridge short interruptions, allow for orderly shutdown during extended outages, and isolate sensitive equipment from transient events. For extended backup power, a standby generator is required.
When a facility’s power quality strategy includes standby generation, the generator’s voltage and frequency regulation capabilities directly affect how robotic systems behave on backup power. Industrial-grade generators with electronic governors and automatic voltage regulators (AVRs) can maintain frequency within ±0.25 Hz and voltage within ±1% of nominal — tight enough that most robotic systems will operate normally on generator power without modification.
Generator selection for robotic facilities should include evaluation of the generator’s transient response — how quickly it recovers voltage and frequency after a sudden load application or rejection. A generator that takes several seconds to stabilize after a large load step may cause robot faults during that stabilization period, even if its steady-state regulation is excellent.
This is one reason why the Generac Industrial platform — with electronic isochronous governing and integrated digital AVR — is well-suited to manufacturing facilities with sensitive robotic loads. The transient response characteristics are specifically engineered for facilities where load steps are large and fast, which is exactly what robotic production environments present.
Battery energy storage integrated with the facility’s electrical distribution provides several power quality benefits beyond simple backup power. BESS systems can respond to voltage sags in milliseconds — faster than any generator can respond — providing ride-through for the brief sag events that trigger most robotic nuisance trips. When combined with a standby generator, a BESS handles the immediate transient while the generator starts and stabilizes, eliminating the brief interruption that would otherwise occur during generator transfer.
BESS systems also address harmonic distortion through active power factor correction capabilities in some configurations, and can provide voltage support during utility grid events without requiring the facility to transfer to generator power at all.
Where harmonic distortion is identified as a contributing factor to robot control problems, several mitigation approaches are available: passive harmonic filters tuned to the dominant harmonic frequencies present in the facility; active harmonic filters that dynamically cancel distortion across a broader spectrum; or isolation transformers with electrostatic shielding that block high-frequency noise from reaching sensitive equipment. The appropriate solution depends on the specific harmonic profile of the facility, the sensitivity of the affected equipment, and the economics of each approach.
Assuming the utility is the problem. In many Michigan manufacturing facilities, the power quality issues affecting robotic systems originate inside the fence — from motor loads, welding equipment, and the robots’ own drives. A power quality assessment that only looks at the utility metering point misses the internally generated disturbances that often cause the most frequent nuisance trips.
Sizing UPS for the robot controller only. A robot controller that stays powered through an outage doesn’t help much if the vision system, the safety PLC, and the conveyor interface modules all lose power at the same time. Power quality protection for robotic cells needs to be scoped to include all the equipment whose loss would halt the cell or require a lengthy restart sequence.
Selecting a generator without evaluating transient response. Generator specifications typically emphasize steady-state voltage and frequency regulation. For robotic facilities, transient response to load steps is equally important and is often not evaluated during the selection process.
Neglecting transfer switch timing. Even with a well-specified generator, a transfer switch that takes 10 seconds to transfer may be long enough to cause robot safety systems to de-energize and require re-homing. Fast-acting transfer switches — or a BESS bridge that eliminates the interruption entirely — are worth evaluating for facilities where restart time after a transfer is operationally significant.
If your facility is experiencing unexplained robot faults, nuisance trips, or drive component failures at higher than expected rates, a systematic approach helps identify the cause:
Start with a power quality survey using a recording power quality analyzer at the robot controller input, capturing voltage, current, frequency, harmonic spectrum, and event data over at least a week of normal production. The data will reveal whether the problems correlate with utility events, internal load switching, or specific production cycles.
Review robot controller event logs alongside the power quality data. Most modern robot controllers log fault conditions with timestamps precise enough to correlate with power quality events.
Evaluate your backup power infrastructure against the specific transient response and frequency regulation requirements of your robotic equipment. If your generator was specified for a simpler load profile, it may not be adequate for today’s robotic production environment.
Work with your electrical engineer of record on any power conditioning or distribution modifications. Changes to the facility’s power distribution system require engineering evaluation and, typically, permit coordination with your local jurisdiction.
Wolverine Power Systems is Michigan’s Premier Generac Industrial Energy Distributor, serving manufacturing facilities throughout all 83 Michigan counties from four strategically located facilities: Zeeland (serving West Michigan and Grand Rapids Metro), Wixom (serving Southeast Michigan and Metro Detroit), Gaylord (serving Northern Michigan and Traverse City area), and Marquette (serving the entire Upper Peninsula). We work with facilities teams and their electrical engineers on backup power systems designed for the specific load characteristics of robotic and automated manufacturing environments — including generator selection for tight voltage and frequency regulation, BESS integration for seamless transfer, and load bank testing to verify performance before you need it.
If your facility is planning a robotics expansion, upgrading existing backup power infrastructure, or experiencing power quality issues affecting production, we’re happy to discuss your specific situation.
Call 800-485-8068 or visit wolverinepower.com/industrial-and-commercial-generators to start the conversation.
Power quality refers to how closely your electrical supply matches the voltage, frequency, and waveform characteristics that equipment was designed to receive. Industrial robots are exceptionally sensitive to power quality because their servo drives, motion controllers, and safety systems require stable, clean power to maintain precision. A voltage sag that a standard motor might tolerate can halt a robotic production line, corrupt controller memory, or trigger safety shutdowns requiring manual reset. In Michigan manufacturing facilities running just-in-time production, a single power quality event can cost thousands of dollars in downtime and lost production.
Michigan manufacturers typically encounter four main power quality issues with robotics. First, voltage sags from utility grid events during ice storms and severe weather cause robot controllers to trip unexpectedly. Second, internal voltage sags from large motor starts (stamping presses, welding equipment, air compressors) create disturbances on the facility’s own electrical system. Third, harmonic distortion accumulates when multiple VFDs and robot drives operate simultaneously, exceeding IEEE 519 limits and degrading controller performance. Fourth, generator transition events during backup power transfers can trigger robot faults if the generator’s frequency or voltage regulation isn’t tight enough. Additionally, facilities in rural Northern Michigan and the Upper Peninsula experience more weather-related power quality events than urban areas.
Michigan manufacturers typically encounter four main power quality issues with robotics. First, voltage sags from utility grid events during ice storms and severe weather cause robot controllers to trip unexpectedly. Second, internal voltage sags from large motor starts (stamping presses, welding equipment, air compressors) create disturbances on the facility’s own electrical system. Third, harmonic distortion accumulates when multiple VFDs and robot drives operate simultaneously, exceeding IEEE 519 limits and degrading controller performance. Fourth, generator transition events during backup power transfers can trigger robot faults if the generator’s frequency or voltage regulation isn’t tight enough. Additionally, facilities in rural Northern Michigan and the Upper Peninsula experience more weather-related power quality events than urban areas.
Most industrial robot controllers are designed to operate within ±10% of nominal voltage under steady-state conditions. However, during voltage transients and sags, the tolerance is much tighter. SEMI F47, the widely adopted standard for automation equipment, specifies that systems should ride through voltage sags to 50% of nominal for up to 200 milliseconds and sags to 70% for up to 0.5 seconds without tripping. In practice, many robot controllers will fault on voltage sags that exceed these thresholds, requiring manual intervention to restore operation. Therefore, power conditioning or UPS protection is often necessary to meet these requirements in Michigan facilities where utility voltage sags are common during storms.
When a voltage sag occurs, the robot controller’s power supply may momentarily dip below the threshold required for stable operation. Consequently, the controller may execute a controlled shutdown, trigger a safety system fault, or lose its position reference requiring re-homing of all axes. Furthermore, even a brief sag lasting only a few cycles can corrupt data in the controller’s memory or cause communication errors with peripheral devices like vision systems and safety PLCs. In facilities with complex robotic cells, recovering from a voltage sag event can take 30 minutes or more while technicians diagnose faults, clear alarms, re-home robots, and verify safe operation. Meanwhile, production remains halted and downstream operations may be affected.
IEEE 519-2022 is the primary U.S. standard for controlling harmonic distortion in industrial power systems. It establishes voltage and current distortion limits at the point where your facility connects to the utility (the point of common coupling). Most Michigan facilities with significant robotic installations should evaluate their harmonic distortion levels against IEEE 519 limits. Although IEEE 519 is a recommended practice rather than a legally enforceable code, exceeding its limits can damage sensitive equipment, reduce transformer and motor life, and cause nuisance trips in robot controllers. Moreover, utilities may require compliance if your facility’s harmonic distortion affects other customers on the same distribution circuit. A power quality survey will reveal whether your facility meets IEEE 519 limits or requires harmonic mitigation.
A properly sized double-conversion UPS provides excellent protection against voltage sags, brief interruptions, frequency deviations, and transient events. However, UPS systems have limitations that facilities managers should understand. First, runtime is typically measured in minutes, not hours—sufficient for brief utility interruptions but not for extended outages. Second, the UPS must be sized to power not just the robot controller but all equipment whose loss would halt the cell (vision systems, safety PLCs, conveyor interfaces). Third, UPS batteries require regular maintenance and eventual replacement. Finally, for extended backup power during multi-hour outages, you’ll still need a standby generator. Nevertheless, combining a UPS for short-term ride-through with a generator for extended runtime provides comprehensive protection for Michigan facilities.
UPS systems and standby generators serve complementary roles in protecting robotic systems. A UPS responds instantaneously to power quality events, providing clean, conditioned power during voltage sags and brief interruptions measured in minutes. It eliminates the brief transfer interruption when switching to backup power. Conversely, a standby generator provides extended runtime measured in hours or days during utility outages but takes 10-15 seconds to start and stabilize. Additionally, generator power quality depends on the unit’s voltage and frequency regulation—not all generators maintain the tight tolerances that sensitive robotic systems require. Therefore, the optimal solution for Michigan manufacturing facilities often combines both: the UPS handles immediate power quality events while the generator provides long-term backup during winter storms or grid failures.
Harmonic distortion creates several problems for robotic systems. First, voltage harmonics cause additional heating in controller power supplies and servo drive components, reducing their service life and increasing failure rates. Second, harmonics can interfere with controller communication systems, causing data errors and spurious faults. Third, current harmonics create circulating currents in three-phase power distribution that waste energy and cause transformer overheating. Fourth, harmonic resonance can amplify specific frequency components to dangerous levels that exceed equipment ratings. Consequently, facilities with high harmonic distortion often experience unexplained robot controller failures, reduced drive component life, and increased maintenance costs. IEEE 519 recommends keeping voltage total harmonic distortion below 5% at the point of common coupling, and robotic systems with particularly sensitive electronics may require even tighter limits.
A power quality survey is strongly recommended before installing significant robotic automation, especially in older facilities where the electrical infrastructure wasn’t designed for sensitive electronic loads. The survey uses recording analyzers to capture voltage, current, frequency, harmonic spectrum, and power quality events over at least one week of normal production. This data reveals whether your facility currently meets the power quality requirements that robot manufacturers specify in their documentation. Furthermore, the survey identifies specific problems (voltage sags from motor starts, harmonic distortion from existing VFDs, utility grid events) so you can design appropriate mitigation before the robots arrive. In Michigan facilities, winter weather creates seasonal power quality challenges that a summer survey might miss, so timing matters. Wolverine Power Systems can coordinate power quality surveys with qualified electrical engineers.
The optimal backup power solution for Michigan robotic facilities typically combines three elements. First, a double-conversion UPS provides immediate ride-through for voltage sags and brief interruptions, eliminating nuisance trips from common power quality events. Second, a standby generator with tight voltage and frequency regulation (±1% voltage, ±0.25 Hz frequency) provides extended runtime during winter storms and utility outages. Third, a fast-acting automatic transfer switch (or BESS bridge) minimizes the interruption during transition from utility to generator power. Additionally, the generator must be sized not just for steady-state load but also for the transient load steps that occur when multiple robots and their associated equipment start simultaneously. Generac’s industrial generators with electronic isochronous governing are specifically engineered for facilities where these tight tolerances matter.
Battery Energy Storage Systems (BESS) provide an excellent solution for eliminating the brief interruption that occurs when transferring from utility power to generator backup. Traditional transfer switches create a 50-200 millisecond interruption during the transfer—long enough to trigger robot safety systems even when the generator is running perfectly. In contrast, a properly configured BESS responds in milliseconds to support the load during the transfer, creating a seamless transition that robots never detect. Moreover, BESS systems provide additional benefits: they mitigate voltage sags without requiring generator startup, support harmonic filtering in some configurations, and enable load shifting during peak demand periods. For Michigan facilities where every second of robot uptime matters, BESS integration represents a significant advancement over traditional UPS-only or generator-only backup strategies.
Nuisance trips—robot controller faults that occur without any actual equipment malfunction—typically result from power quality events that exceed the controller’s tolerance. Common causes include voltage sags from large motor starts elsewhere in the facility, utility grid disturbances during storms, harmonic distortion that interferes with controller electronics, and brief interruptions during generator transfers. Prevention strategies depend on identifying the specific root cause through power quality monitoring. Solutions may include: installing a UPS to ride through voltage sags and brief interruptions, adding harmonic filters to reduce distortion, coordinating motor starts to avoid cumulative voltage sags, upgrading to a generator with tighter voltage regulation, or implementing BESS for seamless power transfer. In Michigan manufacturing facilities, addressing nuisance trips often recovers significant production capacity—30 minutes of recovery time per event multiplied by dozens of events per year adds up to substantial lost production that proper power quality infrastructure prevents.
Wolverine Power Systems is Michigan’s Premier Generac Industrial Energy Distributor, serving commercial and industrial facilities since 1997. With four locations across Michigan — Zeeland, Wixom, Gaylord, and Marquette — our experienced team provides generator sales, installation coordination, preventive maintenance, emergency service, and parts for facilities throughout all 83 Michigan counties.
Contact: 800-485-8068 | wolverinepower.com
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