If your company experiences sudden line stoppages, PLC resets, HMI lockouts or abnormal machine restarts, the cause may be a short disturbance in the electrical network. In many cases these are voltage sags or micro-interruptions: events lasting less than one second, often difficult to detect without power quality analysis tools, but sufficient to interrupt production cycles and generate high costs.
Short network disturbances are not all the same. Some appear as temporary voltage drops, while others are actual interruptions lasting just a few milliseconds.
Voltage sags are temporary reductions in nominal voltage below a defined threshold (CEI EN 50160 standard).
Micro-interruptions are complete voltage drops lasting 10-500 ms. Their effects are often underestimated.
Invisible to operators, costly in their effects.
The two phenomena are often confused, but they have different characteristics and require different solutions.
Drop between 10% and 90% of the nominal value, lasting between 10 ms and 1 minute (Reference standard: CEI EN 50160).
Voltage drops to zero for a very short time: typically between 50 and 500 ms. It is often not detected by standard monitoring systems, but it is more frequent than one might think.
The most frequent causes of this type of disturbance include:
In general:
In both cases, the electricity supply may be formally compliant with current regulations while still causing production downtime. The issue is not the electricity supplier, but the sensitivity of modern equipment.
| Characteristic | Voltage sag | Micro-interruption |
| Type of disturbance | Partial reduction in voltage | Complete voltage drop |
| Voltage value | Between 10% and 90% of the nominal value | Voltage at zero |
| Typical duration | From 10 ms to 1 minute | Typically from 50 to 500 ms |
| Detection | Requires power quality monitoring | Often difficult to detect with standard tools |
| Recommended solution | Oxygen | Oxygen Zero |
Any process with continuous automation, robotics or electronic control is highly sensitive. The sectors that record the highest costs are:
Most of the costs related to poor power quality are caused precisely by voltage sags and micro-interruptions.
In economic terms, this impact can represent up to 4% of a company’s annual turnover.
The damage is not limited to equipment, but extends to interrupted processes, unplanned downtime, performance degradation and increased maintenance costs.
To estimate the cost of these events, a practical rule can be applied: line downtime cost (€/hour) x average restart time x monthly event frequency.
It is not always possible to distinguish them without carrying out an analysis: both can cause machine downtime, PLC resets, HMI lockouts or sudden faults.
To identify with certainty which phenomenon affects your plant, a power quality measurement with instrumental analysis of the electrical parameters is required.
Do you want to understand whether your plant has problems with voltage sags or micro-interruptions? Request a power quality analysis.
Ortea Next offers two specific solutions to protect industrial plants from short network disturbances.
For voltage sags, the ideal solution is Oxygen, designed to counter longer-lasting voltage sags. Thanks to an ultra-fast response of less than 3 milliseconds, it ensures voltage continuity without using batteries, guaranteeing high performance with low operating costs. It also regulates output voltage up to ±15% in continuous mode.
For micro-interruptions, Oxygen Zero is the best choice. Its architecture with supercapacitors and IGBT technology makes it ideal for highly sensitive industrial environments, protecting the most delicate devices from very short but frequent disturbances. It intervenes in less than 5 ms and compensates micro-interruptions up to 1 second at full load (with possible extension through derating).
Choosing Ortea Next means relying on a dependable partner with over 50 years of experience in the sector and a complete range of solutions for energy efficiency. Every product is designed and manufactured in Italy, according to a rigorous certified quality system. Solutions are sized to measure, based on the energy profile and specific criticalities of each plant. It is not just about protection: improving power quality means increasing overall efficiency, reducing hidden costs and enhancing investments over time.
A voltage sag is a partial reduction in nominal voltage (between 10% and 90%), lasting from 10 ms to about 1 minute. A micro-interruption is a complete voltage drop (to zero) for a very short time, typically between 50 and 500 ms. Both can stop production, but they require different technologies to be corrected.
The most common signs are: line stoppages with no apparent cause, recurring PLC or drive resets, intermittent alarms on machines that show no physical faults, and increased maintenance costs on electronics. Ortea Next performs power quality measurement services directly on site, with reports that identify the frequency, depth and duration of network disturbances.
It depends on the cost of line downtime and the frequency of events. In plants with continuous processes, even 3-5 plant shutdown events per month can translate into tens of thousands of euros per year in lost production, waste, rework and accelerated wear of electronics.
Traditional UPS systems, although effective, are bulky, require periodic maintenance and have lower energy efficiency. Oxygen and Oxygen Zero provide targeted and more efficient protection.
