Iskra: Energy meters, power-quality analysers and electrical components from Ljubljana

Overview

Iskra has made electricity meters since its first years. Its own timeline starts in 1946 with the E1 single-phase induction meter and adds the T1 three-phase meter in 1956, so metering is one of the oldest lines in a business that has since grown into capacitors, low-voltage switchgear, power automation and protection, professional batteries, telecommunications and antennas. The company lists those as separate business segments, with electrical measuring instruments as one of them.

The measuring range is unusually wide for a single manufacturer. At one end are small DIN-rail energy meters for submetering and charge points; at the other are permanent power-quality analysers certified to class A of IEC 61000-4-30, the standard that utilities and grid operators use when the measurement method itself has to be defensible. Between them sit panel multimeters, network recorders and measuring transducers that feed control systems.

What sets Iskra apart in the meter market is its early move into EV charging. The WM3M4C signs every charging transaction, and Iskra announced Eichrecht certification for its hardware and software in October 2021, which is what German charge-point operators need to bill by the kilowatt-hour. The company describes itself as family-owned, led by Dušan Šešok and his sons Klemen and Matija.

Offering

Energy meters

The smart energy meter range covers single-phase IE14xx meters, three-phase IE38Mx and WM3x6 meters, the compact WM1, and the WM3M4 family for charge points. The WM3x6 is a three-module, direct-connected meter for 5(65) A, class 1 or MID class B, with infrared as standard and RS-485, M-Bus, a pulse output and a tariff input as options. The WM3M4 and WM3M4C measure import and export at 5(40) A in two- or four-wire networks, run from minus 25 to plus 70 °C and carry MID class B approval to EN 50470-3. The V2 versions add cable-loss compensation and OCMF 1.3.0.

Multifunction meters and power-quality analysers

The power monitoring range runs from the iMC740 multifunction meter and iMC750 network recorder to the iMC770, iMC774 and iMC784A power-quality analysers. The iMC3X0 measuring centres measure to class 0.5 for voltage, current and power and class 0.5S for active energy, with harmonics to the 31st; the iMC350 adds an 8 MB recorder. The iMC784A is the top of the range, described below.

Transducers, gateways and software

Measuring transducers turn network quantities into signals for control systems: the iMT5xx multifunction family, single-phase iMT510 to iMT518 units, iMT4xx voltage, current and frequency transducers, and an iRD500 remote display that sets up an iMT5xx without a PC. Smart gateways bridge infrared and RS-485 meters to a network, and the MiQen software configures and monitors the instruments and Iskra protection relays. Hardware is sold through distributors and the company's B2B shop; prices are not published.

Technology

Modbus on the energy meters

Iskra publishes full register tables in its manuals. The WM3M4 user's manual, version 2.13 for firmware 2.12, documents Modbus RTU on both the RS-485 terminals and the infrared port. Addresses are written as the 30000 input-register reference plus an offset, and most measurements use Iskra's own T5, T6 and T7 data types, in which the top byte carries a signed power-of-ten exponent rather than a fixed scale. A reader that assumes plain 32-bit integers or IEEE floats will decode them wrongly. The WM3M4C keeps the same measurement registers and adds transaction, time and signature registers for the charging controller, with ECDSA signatures over each charging session.

Iskra also publishes change notices. PCN 2024-002 of August 2024 records a housing change and the move from firmware 2.05 to 2.12 on the WM3M4 and WM3M4C, which tells an integrator which manual edition matches an installed meter.

Multimeters and power quality

The iMC3X0 offers isolated RS-485 or RS-232 at up to 115,200 bit/s with Modbus, DNP3 and M-Bus, plus USB. The iMC784A samples four voltage and four current channels at 32 kHz, measures more than 700 quantities including harmonics and interharmonics to the 63rd order, and stores 8 GB of records in PQDIF (IEEE 1159.3) or COMTRADE (IEEE C37.111). Up to eight analysers share triggers over Ethernet, and recordings are retrieved by FTP or through MiQen Setting Studio. NMi certified its method under certificate NMi-CoC-21.31R01 as class A to IEC 61000-4-30 Ed. 3, covering frequency, voltage magnitude, flicker, dips and swells, unbalance and harmonics.

Approvals and quality systems

Billing meters carry MID type examination, and the WM3M4C holds Eichrecht Module B and Module D certificates. The company holds ISO 9001, ISO 14001 and ISO 45001 certificates, and its timeline records the accreditation of Iskra Laboratories by the Slovenian accreditation body in 2003.

Markets

Iskra says it sells in more than 100 countries and lists more than 10,000 products across its segments. The measuring range serves four distinct buyers. Panel builders and electrical contractors use the DIN-rail meters for tenant and circuit submetering in residential, commercial and industrial buildings. Charge-point manufacturers build the WM3M4 and WM3M4C into AC chargers, where MID approval covers billing across the EU and Eichrecht signing covers Germany. Utilities and grid operators use the class A analysers for permanent supply-quality monitoring from generation, including renewable plants, through transmission and distribution. Industrial users and system integrators use the transducers and multimeters to bring electrical values into control and SCADA systems over Modbus or DNP3.

The company has grown its regional base through acquisitions in Croatia. It bought the Šibenik shipyard in 2019 and the Zagreb cable maker Elka in 2021, which N1 reported as the largest electric cable producer in that part of Europe. In 2024 it took a majority stake in Elmap of Split, which automates water and wastewater treatment, and its timeline adds Experio and ASIST in 2025 and the 3. Maj shipyard in Rijeka in 2026. Those deals widen the group's industrial, marine and infrastructure work more than its metering line.

Company

Legal entity

The operating company is ISKRA, elektro in sistemske rešitve, d.o.o., a limited liability company at Stegne 21 in Ljubljana. The Slovenian business register listing gives registration number 5185726000, VAT number SI13278088 and an entry date of 22 November 1990. Iskra dates the business itself to 1946, when it developed its first meters and switches, and in 1961 it opened its Otoče plant and merged with Iskra Capacitors Semič. Several of its own pages, including the MiQen description, still use the older name Iskra d.d.

The name Iskra is shared with other companies that came out of the former Yugoslav Iskra group. This profile covers the Ljubljana company at iskra.eu only.

Ownership and leadership

Iskra is family-owned. Dušan Šešok is chief executive and majority owner, as Lider reported in 2024, and the company names his sons Klemen and Matija as part of its leadership.

Growth

In 2021 N1, citing HINA, reported more than 1,300 employees, a record €130 million of consolidated revenue in 2020 and share capital of just over €28 million. By 2023 consolidated revenue was nearly €300 million, according to Lider, and the company now cites 1,650 employees. The acquisition of Elka, announced by Iskra in May 2021 for 100% of the shares, accounts for part of that rise.