PQSys combines fixed installed network analyzers, fault recorders and WebPQ® analysis software for continuous monitoring of power grids and facilities. The system enables traceable evaluation of events and power quality.
Typical applications:
- Continuous monitoring when faults need to be reliably detected
- Objective clarification in the event of complaints, audits or disputed causes
- Comparison of network conditions before and after operational changes
- Ongoing transparency at sites with sensitive processes or critical consumers
These Devices Are Suitable When:
- Permanent recording is required instead of temporary analysis.
- Events must be documented for internal decisions or for third parties.
- Measures should be prioritised and justified on the basis of objective data.
- Multiple measuring points across power grids and facilities must be monitored consistently.
Products
Fixed Installed Power Quality Devices and Network Analyzers
PQI-LV: Enhancing Transparency in the Low-Voltage Grid
PQI-DE: The Fix-Installed Tool for Power Quality Experts
PQI-DA Smart: The Fix-Installed Power Quality Allrounder
PQI-D: The Flexible (*discontinued, can only be ordered until 31.12.2026)
I-Sense: Feeder Current Measurement Technology for up to 16 Feeders
Application Areas
PQSys - Continuous Network Monitoring
A. Eberle GmbH & Co. KG
Measure. Regulate. Across All Grids.
A. Eberle GmbH & Co. KG, founded in 1980 and headquartered in Nuremberg, Germany, operates in the field of measurement and regulation technology for the energy sector as well as for medium-sized and large industrial companies. Our products and services ensure and enhance the availability of energy supply across all voltage levels and support the integration of renewable energy sources into power grids.
»PQSys« - Fixed Installed Network Analyzers and Fault Recorders Across All Voltage Levels
For Continuous Power Quality Monitoring and Structured Event Analysis
The fixed installed PQI-LV, PQI-DA smart and PQI-DE are network analyzers and fault recorders for power quality monitoring in low-, medium- and high-voltage networks. Depending on the device, they can be used as fault recorders with sampling rates of up to 41 kHz, as power quality measurement devices in accordance with EN 50160, IEC 61000-2-2 and IEC 61000-2-4, or as power quality analyzers.
The network analyzers support the monitoring of defined power quality standards and agreements between energy suppliers and customers. They can also be used in networks with photovoltaics, e-mobility, battery storage and heat pumps, as well as for low-voltage grid monitoring and industrial applications.
All power quality analyzers from A. Eberle are characterized by the highest measurement accuracy of class A according to IEC 61000-4-30 Ed. 4. The standard specifies power quality parameters, measurement methods, time aggregation, accuracy and evaluation, thus guaranteeing reliable, reproducible and comparable measurement results.
Power Quality Analysis Software
For Our Fixed Installed Solutions
WebPQ®
The Easy Way to Analyse Your Power Quality Measurement Data
WebPQ® is the central analysis software for A. Eberle’s fixed installed network analyzers, fault recorders and power quality monitoring devices. Support for evaluating measurement data from portable power quality analyzers is available in upcoming versions.
*upcoming versionsNEW: Power Quality Services by A. Eberle
We Support You With Your Grid Analysis Projects
Power Quality
Services
Expert Knowledge That Moves You Forward
We offer you power quality audits with troubleshooting in accordance with EN 50160 and IEC 61000 and support you with our expert know-how. As the market leader in the field of mobile power quality devices, we can draw on a wide range of network analyzers with the appropriate accessories for our services.
Our Portfolio at a Glance
»PQSys« - Fixed Installed Power Quality Network Analyzers & Fault Recorders
Quick Comparison of Network Analyzers:
PQI-LV vs. PQI-DA smart vs. PQI-DE
Find the Right Network Analyzer for Your Application.
PQI-LV
PQI-DA smart
PQI-DE
• Secondary substation
• Depth of the grid (cable-/light-/sub-distributors)
• Industrial power grids (machinery/processes & plants)
• Retrofits
Low-voltage
✔️
10.24 kHz / Optional 40.96 kHz (B1)✔️
✔️
2 kHz to 20 kHz according to IEC 61000-4-7 via software option (B1)✔️
CCCI, SSH, HTTP(S)Modbus RTU & TCP (Standard)
✔️
IEC 60870-5-104 (P1), IEC 61850 (P2), Modbus Master (P3) MQTT*✔️
Radius, RBAC, URM, encryption✔️
1 GB ~ 140 weeks with standard template❌
DIN-rail
130 x 90 x 58 mm
L x W x HDirect
230 / 400 / 690 VRogowski coils & current sensors
350 mV input
❌
❌
❌
Optional
• PCC / Point of Common Coupling (IEC 61000-2-2)
• POC / Point of Connection (EN 50160)
• Secondary substation with increased requirements
• Industrial applications
Low-, medium- and high-voltage
✔️
10.24 kHz / Optional 40.96 kHz (B1)✔️
✔️
2 kHz to 20 kHz according to IEC 61000-4-7 via software option (B1)✔️
CCCI, SSH, HTTP(S)Modbus RTU & TCP (Standard)
✔️
IEC 60870-5-104 (P1), IEC 61850 (P2), Modbus Master (P3) MQTT*✔️
Radius, RBAC, URM, encryption✔️
1 GB ~ 140 weeks with standard template1.7 inches
DIN-rail,
Front panel installation using adapter
160 x 90 x 58 mm
L x W x HDirect and transducer measurement
100 / 230 / 400 / 690V1 A/5 A measuring transformer (C30)
1A/5A protection transformer (C30)
Rogowski coils (C40)
Sensor technology (C44)
DC (C45)
2 / 2
❌
❌
✔️
• Substations
• Industrial applications
• Grid code compliance
• High-precision frequency measurements
• Residual Current Monitoring (RCM)
Low-, medium- and high-voltage
✔️
10.24 kHz / Optional 40.96 kHz (B1)✔️
✔️
2 kHz to 20 kHz according to IEC 61000-4-7 via software option (B1)✔️
CCCI, SSH, HTTP(S)Modbus RTU & TCP (Standard)
✔️
IEC 60870-5-104 (P1), IEC 61850 (P2), Modbus Master (P3) MQTT*✔️
Radius, RBAC, URM, encryption✔️
1 GB ~ 140 weeks with standard template5 inches
Front panel installation
144 x 144
144 x 144 x 90 mm
L x W x HDirect and transducer measurement
Small signal transducer (E3)
1A/5A measuring transformer (C30)
1A/5A protection transformer (C30)
Rogowski coils (C40)
Mini current clamps (C44)
DC (C45)
8 / 4
✔️
5th current feeder (30 mA)✔️
PT100 / PT1000 / KTY✔️
FAQ – Frequently Asked Questions
What is a power quality monitoring system?
A power quality monitoring system continuously records and evaluates voltage quality, events and disturbances in electrical networks. It helps operators detect abnormalities early, document incidents and improve grid transparency.
When is a fixed installed network analyzer the right choice?
A fixed installed network analyzer is suitable when power quality must be monitored continuously, recurring faults need to be recorded reliably, or events must be documented for audits, complaints or technical decisions.
Which standards are relevant for power quality monitoring?
Power quality monitoring is commonly based on standards such as EN 50160 for voltage characteristics and IEC 61000-4-30 for measurement methods and accuracy classes.
What is the benefit of integrated fault recording?
Integrated fault recording documents disturbances and events for structured evaluation. This supports root cause analysis and helps operators make objective technical decisions based on recorded data.
Which applications benefit from permanent power quality monitoring?
Typical applications include substations, industrial plants, functional buildings, emergency power systems, data centres, battery storage systems, PV-connected low-voltage grids and renewable energy installations.
What is the difference between a mobile and a fixed power quality analyzer?
A mobile analyzer is mainly used for temporary troubleshooting and short-term measurements. A fixed installed analyzer is designed for continuous monitoring, long-term transparency and permanent event documentation.
How does WebPQ® support the monitoring process?
WebPQ® serves as the central analysis software for fixed installed fault recorders and power quality monitoring devices. It supports structured evaluation of measurement data across devices.
Which device is suitable for low-voltage monitoring?
PQI-LV is positioned for low-voltage applications, especially where compact installation and transparency in the low-voltage grid are important.
Which network analyzers are suitable for broader grid and expert applications?
PQI-DA smart is suitable for applications in low-, medium- and high-voltage networks, including PCC, POC, secondary substations and industrial systems. PQI-DE covers the same voltage levels and is also positioned for substations, grid code compliance, high-precision frequency measurements and residual current monitoring.
Why is permanent monitoring valuable for critical infrastructure?
Permanent monitoring provides traceable records of power quality and events at sensitive sites such as data centres, industrial facilities and emergency power systems. It helps operators evaluate disturbances consistently and base technical decisions on objective measurement data.
News From the Product Group
PQSys - News
Blogpost
PQ-Box Trade-in Promotion: Only From October 1 to December 31 2026
1. October 2026
For a limited time: Receive a discount for the trade-in of your PQ-Box 100 or a comparable external old device (3-phase power quality analyser). Click here for further information![...]
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Blogpost
GRUNDIG AKADEMIE visits A. Eberle
7. August 2026
In 2026, the GRUNDIG AKADEMIE Nuremberg visited A. Eberle with a group of trainee technicians. During the visit, the participants gained an insight into our company, technical fields of work and potential[...]
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Blogpost
A. Eberle named one of the TOP 100 Innovators for 2026
22. July 2026
As part of the 2026 TOP 100 Awards, we had the honour of receiving a special accolade in Heidelberg last week – presented in person by Christian Wulff, former Federal President and mentor of the TOP[...]
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General Knowledge
Digital Substation
17. June 2026
A digital secondary substation combines measurement, fault location and secure data analysis to improve transparency across medium- and low-voltage distribution grids.[...]
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Blogpost
International Partner Week 2026 - Exchange, knowledge transfer and collaboration in Nuremberg
1. June 2026
We were delighted to welcome our international partners to Partner Week 2026. The chance to chat in person, seeing familiar faces and making new acquaintances made the week a special one for us.[...]
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Webinar
»PQSys« Webinar: PQ-Monitoring & Feeder Current Measurement in Low-Voltage Grids 4
28. May 2026
Webinar recording from 2026-05-13: »PQSys - PQ-Monitoring & Feeder Current Measurement in Low-Voltage Grids - part 4«. [...]
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General Knowledge
Measuring Equipotential Bonding
13. May 2026
Measuring equipotential bonding is essential for verifying low-resistance, continuous connections between conductive parts. This article explains equipotential bonding, relevant standards, typical measurement[...]
Read more
General Knowledge
Insulation Resistance and Insulation Measurement
30. April 2026
Insulation measurement helps assess the safety and condition of electrical installations. This article explains insulation resistance measurement, relevant limits, test voltages and practical interpretation[...]
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Blogpost
A. Eberle and Bregal Unternehmerkapital enter into a growth partnership
14. April 2026
A. Eberle and Bregal enter into a growth partnership. The partnership with BU is intended to accelerate A. Eberle’s international expansion, innovation and technological advancement.[...]
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General Knowledge
Power Plant Controller: Measurement Values at the Grid Connection Point
26. March 2026
Power Plant Controller operation at the grid connection point depends on low-latency, accurate, and dynamically reliable measurement values. This article explains the technical requirements, the role of[...]
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General Knowledge
Measuring Harmonics: Detecting Disturbances in Buildings
6. March 2026
Harmonic distortion and supraharmonics can cause flicker, nuisance tripping and device malfunctions in modern buildings. This article explains how to measure harmonics at the socket outlet and interpret[...]
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Blogpost
Power Quality Monitoring for Electrical Contractors - Mobile Network Quality Measurement with the PQ-Box ONE
2. March 2026
How a portable power quality analyzer like the PQ-Box ONE helps electrical professionals identify voltage disturbances, improve documentation and make reliable technical decisions.[...]
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Blogpost
Power Quality Monitoring: Risks of Poor Power Quality
18. December 2025
Power quality monitoring translates “invisible” disturbances into measurable causes and KPI impacts. This guide explains common power-quality events and a practical workflow to measure, evaluate and[...]
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Webinar
»Cyber Security« Webinar: A Challenge for European Energy Companies
3. December 2025
Webinar recording from 2025-11-26: »Cyber Security« - A Challenge for European Energy Companies[...]
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Blogpost
A. Eberle at the Schwabach City Run 2025
24. November 2025
A. Eberle was represented by 37 participants at the 2025 Schwabach City Run, setting a new internal record for participation. Particularly noteworthy is Benjamin Rentsch's first place in the M 35 40 age[...]
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General Knowledge
Total Harmonic Distortion (THD) in Low Voltage Networks
20. November 2025
This study examines harmonic distortion in modern low-voltage grids, showing real measurement data, key standards (EN 50160, IEC 61000-3-2/-4-30) and practical ways to reduce THD in applications such as[...]
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Special Publication
Power Quality Monitoring in Buildings - A Key Factor in Modern Building Design
12. November 2025
Discover how Power Quality Monitoring in Buildings improves reliability, efficiency and grid stability. Learn more in our technical article.[...]
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Special Publication
Continuous Power Quality Monitoring in the Jupiter Data Centre - Voltage Quality at Exascale Level
5. November 2025
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Webinar
»PQSys« Webinar: »WebPQ®« - The New Power Quality Software for Continuous Grid Monitoring
27. October 2025
Webinar recording from 2025-09-25: »PQSys« Webinar: »WebPQ®« - The New Power Quality Software for Continuous Grid Monitoring [...]
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