What is a fixed-installed power quality system used for?

A fixed-installed power quality system is used for permanent monitoring of voltage quality, events and disturbances in electrical networks. It documents recurring faults, provides traceable data for audits or complaints and supports continuous transparency at critical sites.

What is the difference between temporary analysis and permanent monitoring?

Temporary analysis captures conditions during a limited measurement period, while permanent monitoring records events and quality parameters continuously. Permanent systems are better suited when disturbances occur irregularly, when evidence is needed over time or when several measuring points must be evaluated consistently.

Can PQSys be used across different voltage levels?

Yes. PQSys is designed as a modular system for low, medium and high voltage applications. The product family covers use cases from low-voltage distribution and industrial plants to substations, transformer stations and transmission or distribution grids.

Does PQSys support fault recording and event analysis?

Yes. The fixed-installed analyzers can function as fault recorders and support structured cause analysis. The system records events and disturbances continuously, which helps operators clarify complaints, compare conditions before and after changes and prioritise corrective actions using objective data.

Which devices belong to the PQSys product cluster?

The PQSys product cluster includes PQI-LV, PQI-DA smart and PQI-DE as central fixed-installed analyzers. These devices are combined with WebPQ analysis software and can be configured for continuous power quality monitoring, event recording and evaluation in different grid environments.

Why is IEC 61000-4-30 Class A important for power quality analyzers?

IEC 61000-4-30 Class A is important because it defines how power quality parameters are measured and evaluated. Class A compliance enables reliable, reproducible and comparable measurement results, which is essential when data is used for technical decisions, contractual clarification or third-party documentation.

Seamless Monitoring – Permanent Real-Time Observation

High-Precision Devices – Class A (IEC 61000-4-30 Ed. 4) and Energy Meter Class 0.2s (IEC 62053-22)

Modular & Scalable – Customisable for Every Voltage Level

WebPQ® Analysis Software – Compatible Across Platforms and Devices. Built for the Future.

Seamless Monitoring – Permanent Real-Time Observation

High-Precision Devices – Class A (IEC 61000-4-30 Ed. 4) and Energy Meter Class 0.2s (IEC 62053-22)

Modular & Scalable – Customisable for Every Voltage Level

WebPQ® Analysis Software – Compatible Across Platforms and Devices. Built for the Future.

Our systems enable seamless monitoring of power grids and facilities with traceable evaluation of events and grid quality.

Typical application:

Continuous monitoring when recurring 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 if:

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 in the power grid and network must be monitored consistently.

Products

The Fixed Installed Power Quality Device

Application Areas

PQSys - Continuous Network Monitoring

Battery storage & storage power plants (MV/LV)

Main and sub-distribution boards in industrial and functional buildings

Industrial plants & production facilities

Emergency power systems / emergency power supply

Residential districts with PV, charging points & heat pumps

Data centers & IT infrastructure

Local network stations (MV/LV)

Transformer stations at grid nodes

Transmission & distribution grids (HV/ML/LV)

Substations (HV/MV)

Ground-mounted photovoltaic systems

Onshore windparks

Offshore windparks

Hydroelectric power plants

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« – The All-In-One Solution for Power Grid Transparency Across All Voltage Levels

Seamless Power Quality Monitoring from Low Voltage to High Voltage

The permanently installed fault recorders and power quality network analyzers PQI-LV, PQI-DA smart and PQI-DE form the central components of a system that meets all measurement requirements in low, medium and high-voltage networks. The analyzers can function as fault recorders with a scanning rate of up to 41 kHz, as power quality measurement devices to EN 50160 / IEC 61000-2-2/-4 or as power quality analyzers.

The power quality analyzers are ideal for monitoring specific quality standards and agreements between energy suppliers and customers. They also support the monitoring of new technologies such as photovoltaics, e-mobility, battery storage and heat pumps and offer reliable grid monitoring in the low-voltage range, including industrial applications.

All power quality analyzers from A. Eberle are characterized by the highest measurement accuracy of class A according toIEC 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

The new WebPQ^® is the central analysis software for all fixed installed fault recorders, power quality monitoring devices and for the evaluation of the portable power quality analysers* from A. Eberle.

Learn More

*upcoming versions

NEW: 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.

Learn More

Our Portfolio at a Glance

»PQSys« - Fixed Installed Power Quality Analysers & Fault Recorders

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Quick Comparison:
PQI-LV vs. PQI-DA smart vs. PQI-DE

Q: Which standards are relevant for power quality monitoring with PQSys?

PQSys is positioned for applications that require assessments based on EN 50160 and IEC 61000. Its Class A measurement accuracy is specified according to IEC 61000-4-30 Ed. 4, which defines measurement methods, aggregation intervals, accuracy and evaluation rules for comparable results.

Find the Right Power Quality Analyzer for Your Application.

PQI-LV

PQI-DA smart

PQI-DE

Application

• Secondary substation
• Depth of the grid (cable-/light-/sub-distributors)
• Industrial power grids (machinery/processes & plants)
• Retrofits

Voltage level

Low-voltage

Measurement: 4x Voltage, 4x Current

✔️

10.24 kHz / Optional 40,96 kHz (B1)

IEC61000-4-30 Edition 3 Class A

✔️

Supraharmonic Measurement

✔️

2 kHz to 20 kHz according to IEC61000-4-7 via software option (B1)

SCADA & Communication Protocols – Standard

✔️

CCCI, SSH, HTTP(S)
Modbus RTU & TCP (Standard)

SCADA – License Option

✔️

IEC60870-5-104 (P1), IEC61850 (P2), Modbus Master (P3) MQTT*

IT Security

✔️

Radius, RBAC, URM, encryption

Memory

✔️

1GB ~ 140 weeks with standard template

Display

❌

Design & Mounting

DIN-rail

Dimensions

130 x 90 x 58mm

L x W x H

Voltage Measurement

Direct

230 / 400 / 690V

Current Measurement

Rogowski coils & current sensors
350mV input

Digital Inputs and Outputs (Triggers and Alarms)

❌

RCM Residual Current Measurement

❌

Temperature Input

❌

Fault Recorder / Transient Recorder

Optional

Application

• PCC / Point of Common Coupling (IEC 61000-2-2)
• POC / Point of Connection (EN 50160)
• Secondary substation with increased requirements
• Industrial applications

Voltage Level

Low-, medium- and high-voltage

Measurement: 4x Voltage, 4x Current

✔️

10.24 kHz / Optional 40,96 kHz (B1)

IEC61000-4-30 Edition 3 Class A+

✔️

Supraharmonic Measurement

✔️

2 kHz to 20 kHz according to IEC61000-4-7 via software option (B1)

SCADA & Communication Protocols - Standard

✔️

CCCI, SSH, HTTP(S)
Modbus RTU & TCP (Standard)

SCADA - License Option

✔️

IEC60870-5-104 (P1), IEC61850 (P2), Modbus Master (P3) MQTT*

IT Security

✔️

Radius, RBAC, URM, encryption

Memory

✔️

1GB ~ 140 weeks with standard template

Display

1.7 inches

Design & Mounting

DIN-rail,
Front panel installation using adapter

Dimensions

160 x 90 x 58mm

L x W x H

Voltage Measurement

Direct and transducer measurement

100 / 230 / 400 / 690V

Current Measurement

1A/5A measuring transformer (C30)
1A/5A protection transformer (C30)
Rogowski coils (C40)
Sensor technology (C44)
DC (C45)

Digital Inputs and Outputs (Triggers and Alarms)

2 / 2

RCM Residual Current Measurement

❌

Temperature Input

❌

Fault Recorder / Transient Recorder

✔️

Application

• Substations
• Industrial applications
• Grid code compliance
• High-precision frequency measurements
• Residual Current Monitoring (RCM)

Voltage Level

Low-, medium- and high-voltage

Measurement: 4x Voltage, 4x Current

✔️

10.24 kHz / Optional 40.96 kHz (B1)

IEC61000-4-30 Edition 3 Class A++

✔️

Supraharmonic Measurement

✔️

2 kHz to 20 kHz according to IEC61000-4-7 via software option (B1)

SCADA & Communication Protocols - Standard

✔️

CCCI, SSH, HTTP(S)
Modbus RTU & TCP (Standard)

SCADA - License Option

✔️

IEC60870-5-104 (P1), IEC61850 (P2), Modbus Master (P3) MQTT*

IT Security

✔️

Radius, RBAC, URM, encryption

Memory

✔️

1GB ~ 140 weeks with standard template

Display

5 inches

Design & Mounting

Front panel installation
144 x 144

Dimensions

144 x 144 x 90 mm

L x W x H

Voltage Measurement

Direct and transducer measurement
Small signal transducer (E3)

3.25 / 100 / 230 / 400 / 690V

Current Measurement

1A/5A measuring transformer (C30)
1A/5A protection transformer (C30)
Rogowski coils (C40)
Mini current clamps (C44)
DC (C45)

Digital Inputs and Outputs (Triggers and Alarms)

8 / 4

RCM Residual Current Measurement

✔️

5th current feeder (30mA)

Temperature Input

✔️

PT100 / PT1000 / KTY

Fault Recorder / Transient Recorder

✔️

Learn more about PQI-LV

Learn more about PQI-DA smart

Learn more about PQI-DE

FAQ

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 power quality analyzer the right choice?

A fixed-installed device is the right choice when power quality must be monitored permanently, when recurring faults need to be captured reliably, or when event documentation is required 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?

Fault recording helps capture and analyse disturbances before, during and after an event. This makes root cause analysis faster and supports more objective technical decisions.

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 device is suitable for broader grid and expert applications?

PQI-DA smart and PQI-DE are aimed at more advanced applications across low, medium and high voltage, including industrial, substation and compliance-related measurement tasks.

Why is permanent monitoring valuable for critical infrastructure?

Permanent monitoring creates traceable evidence, supports preventive maintenance and helps operators react faster to voltage disturbances, harmonics and event chains in sensitive environments such as buildings and data centres.

Need More Information?

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PQSys - News

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