Catalog · EN — Siemens Energy catalog (2012, publication no. E50001-G630-A141-V2-4A00) presenting the complete line of surge arrester monitoring devices: the solar-powered ACM Arrester Condition Monitor in basic and advanced versions, 3EX5 030/050 surge counters, the 3EX5 060/062 sensor-and-display pair, the control spark gap, and the portable LCM 500 live condition monitoring system. It explains each device's measuring principle (leakage current, 3rd-harmonic analysis, surge impulse counting, energy absorption logging) and closes with a full comparison table of measured variables, power supply, remote indication, installation, and order numbers.
Surge arresters are among the most dependable components in transmission and distribution systems: operated within specification, they can serve for as long as 30 years with no maintenance at all. Even so, occasional overloads can lead to arrester failure and put network safety at risk, which is why monitoring matters.
As worldwide energy demand pushes existing networks toward their capacity limits, operators increasingly rely on equipment monitoring to record operating states and remaining service life. This data feeds asset management decisions and helps assess the overall condition of the network, with monitors enabling early detection of relevant changes before security of supply is compromised.
Drawing on more than 80 years of surge arrester experience, Siemens offers a complete monitoring line ranging from simple counters and condition indicators to periodic analytic condition monitoring and a future live condition monitoring system - each matched to the voltage level, network situation, and customer requirements.
The ACM advanced builds on the basic version's two core functions: measuring total leakage current with determination of the resistive component via 3rd-harmonic analysis, and registering surge current impulses including their overall number, level, and duration for precise analysis of arrester activity.
It adds automatic long-term trend registration: a daily leakage current measurement at a user-defined time, with results stored for more than five years - far more informative for trend analysis than occasional spot checks. It also logs a detailed surge current history and uniquely registers the energy converted in the arrester per impulse, giving a clear picture of arrester utilization over its service life as an input to asset management.
Data is retrieved wirelessly: the 3EX5 085 USB wireless module and the free Service Tool software connect the ACM to a PC (both devices act as transmitter and receiver) for display, analysis, and evaluation of measured and calculated data, modification of customer-specific parameters, and software updates.
The monitor is solar powered - no external supply, no batteries, and no galvanic connection between the electronics and the arrester's main branch circuit. It already meets the requirements for integration in future ISCM systems (IEC 61850-ready) without hardware replacement, and an installed basic version can be upgraded to advanced with just the USB wireless module, free software, and an access license - no modification of the arrester needed.
The ACM basic provides a wide range of standard condition-monitoring functions: total leakage current measurement and display, surge current impulse metering and display, 3rd-harmonic analysis of leakage current with compensation for network-dependent harmonics, temperature correction, and traffic-light LED condition indication.
From the first day of operation the monitor works in the background, measuring leakage current and compiling a comprehensive counter history (accessible only with advanced monitoring). Upgrading to the advanced system requires no change to the arrester sensor, and the device can even serve as a sensor in future ISCM (integrated station condition monitoring) systems.
Like the advanced version it is solar powered with no galvanic connection to the arrester's main current path, and the entire device is encased in silicone with no hollow spaces, making moisture penetration impossible.
The 3EX5 030 surge counter is the traditional arrester monitor: integrated into the arrester ground connection, it counts the surge arrester responses that have occurred. The 3EX5 050 adds a leakage current meter for monitoring arrester leakage current, indicated by an mA meter as peak value divided by √2 on a bilinear scale, with a measuring range up to 30 mA (or 50 mA on special model 3EX5 050-2).
Both counters can optionally be equipped with a passive auxiliary contact for remote metering (3EX5 030-1, 3EX5 050-1).
| Characteristic | 3EX5 030 | 3EX5 050 |
|---|---|---|
| Response sensitivity, 8/20 µs discharge current | 200 A | 200 A |
| Resolution | 5 impulses per second | 5 impulses per second |
| 4/10 µs high-current impulse | 100 kA | 100 kA |
| Leakage current indication | - | mA meter, peak value / √2 |
| Leakage current measuring range | - | up to 30 mA (normal) or 50 mA (special model 3EX5 050-2) |
| Scale | - | Bilinear |
The 3EX5 060 sensor is integrated into the arrester ground wire, counting arrester responses and continuously measuring leakage current. The companion 3EX5 062 display visualizes those readings at a convenient location and can be installed up to 200 meters from the sensor.
The display unit also provides a connection for local leakage current measurement - for example with an oscilloscope - using a measuring lead available as an accessory.
| Characteristic | Value (3EX5 060/062) |
|---|---|
| Response sensitivity, 4/10 µs and 8/20 µs discharge current | 1000 A |
| Response sensitivity, 30/60 µs discharge current | 200 A |
| Response sensitivity, rectangular-wave discharge current | 100 A |
| Leakage current measuring range | mA meter, up to 20 mA |
| Scale | Logarithmic |
| Sensor-to-display distance | < 200 m |
The control spark gap is a monitor integrated into the arrester's ground wire. It counts arrester responses and allows the current that flowed through the arrester to be estimated from characteristic burn marks.
The LCM 500 is a portable measuring system for metal-oxide surge arresters that measures the 3rd-harmonic component of the leakage current without interrupting operation, providing valuable information on arrester condition. Correction data specific to Siemens arresters is built into the accompanying software.
The catalog concludes with a side-by-side comparison of all seven monitoring solutions across concept, measured variables, power supply, remote indication, installation, and order numbers.
| ACM advanced | ACM basic | Surge counter | Surge counter with leakage current indication | Sensor and display | Control spark gap | LCM 500 | |
|---|---|---|---|---|---|---|---|
| Concept | Electronic | Electronic | Electromechanical | Electromechanical | Electromechanical | Spark gap | Electronic |
| Measured variables | Analyzes surge current impulses (time stamp, peak value, pulse width, energy content); total leakage current; 3rd harmonic of leakage current with temperature correction and harmonic compensation (3 LEDs); arrester energy absorption | Number of surge current impulses; total leakage current; 3rd harmonic of leakage current with temperature correction and harmonic compensation (3 LEDs) | Number of surge current impulses | Number of surge current impulses; total leakage current (including DC) | Number of surge current impulses; total leakage current | Number of surge current impulses | Total leakage current; 3rd harmonic of leakage current |
| Power supply | Solar | Solar | None | None | None | None | Battery / mains |
| Remote indication | Wireless | No | Special model AC: wired via aux. contact | Special model AC: wired via aux. contact | Wired | Special model: via optical fiber | Special model |
| Installation | Integrated into ground wire | Integrated into ground wire | Integrated into ground wire | Integrated into ground wire | Sensor integrated into ground wire / display wired | Integrated into ground wire | Portable / clamp-on ammeter |
| Order no. | 3EX5 080-1; 3EX5 085 (USB wireless module) | 3EX5 080-0 | 3EX5 030; 3EX5 030-1 | 3EX5 050; 3EX5 050-1; 3EX5 050-2 | 3EX5 060; 3EX5 062 | 3EX6 040; 3EX6 020 | LCM 500 |
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