comemso electronics GmbH has introduced the Easy Chester Micro, a portable tester for AC wallboxes and charging stations. The device brings installation checks, vehicle simulation, communication testing and optional electrical-safety measurements into a single field workflow.
A compact tester for AC charging
The Easy Chester Micro weighs 5.4 kg and measures 40 × 30 × 17 cm. Its closed case carries an IP 66 rating, which makes it suitable for demanding service environments.
The tester combines an installation tester and an adapter box in one enclosure. Technicians can therefore carry out commissioning, maintenance, periodic inspection and post-repair verification without using separate instruments.
A 10.1-inch touchscreen guides users through each procedure. The display keeps the current test step, measured value and result visible together, reducing the need to switch between screens or documents.
The device operates through USB-C power. Users can supply it with a 100 W power adapter, a 12 V vehicle adapter or a power bank providing more than 100 W.
Vehicle simulation and charging checks
The Easy Chester Micro acts as the electric vehicle during an AC charging test. It supports the control-pilot communication defined by IEC 61851-1 and SAE J1772.
It measures Control Pilot voltage, PWM duty cycle and Proximity Pilot values. Depending on its configuration, the tester offers either a Type 1 or Type 2 AC inlet.
After the charging station closes its contactors, the device checks whether phase voltage appears at the connector. This confirms whether the station actually releases charging power.
This approach separates electrical safety from charging functionality. A station may pass a basic installation check yet still fail to begin a charging session because vehicle states or authorisation conditions are not met.
ISO 15118-2 communication testing
The tester can establish ISO 15118-2 communication directly. It does not require an external protocol converter for this task.
ISO 15118-2 communication runs over powerline communication, or PLC, according to ISO 15118-3. The test therefore examines both the charger’s PLC chip and the communication link between the charger and the simulated vehicle.
Charging authorisation is handled through External Identification Means, known as EIM. Examples include an RFID card or a mobile app.
The test report records the SLAC connection setup and its attenuation value. It also documents the PLC MAC address of the charging station.
AFIR and communication requirements
The European Union’s Alternative Fuels Infrastructure Regulation, or AFIR, is Regulation (EU) 2023/1804. It establishes requirements for alternative-fuels infrastructure, including publicly accessible charging points.
Since 8 January 2026, newly installed or renovated publicly accessible AC and DC charging points must comply with EN ISO 15118-1 to -5. In practical terms, this includes ISO 15118-2 communication over PLC.
From 1 January 2027, newly installed or renovated public charging points must meet EN ISO 15118-20. The requirement also extends to non-public Mode 3 and Mode 4 charging points.
The Easy Chester Micro supports ISO 15118-2 testing today. comemso plans to add ISO 15118-20 support during the first quarter of 2027.
The device provides part of the evidence for AFIR-related communication requirements. However, it does not replace a complete AFIR conformity assessment.
TLS-secured charging sessions are currently outside the tester’s scope. This limitation matters for operators assessing end-to-end security and advanced Plug & Charge functions.
Electrical safety measurements
Electrical-safety testing is available as an option. The tester can examine both the grid side and the vehicle side of an AC charging installation.
It measures insulation resistance between 250 V and 1,000 V. It also measures protective-conductor resistance at either 200 mA or 25 A.
Residual-current devices can be tested from 6 mA to 300 mA. The tester performs this check for each phase.
On the grid side, the device determines loop impedance and checks phase rotation. On the vehicle side, it measures residual voltage after disconnection.
The applicable test scope depends on local rules, the protection concept and manufacturer instructions. Relevant references include IEC 60364-6, IEC 60364-7-722, German VDE standards and the locally adopted US National Electrical Code.
Fault simulation during charging
Optional fault simulations check whether a charging station stops a session under abnormal conditions. These simulations include a protective-conductor break, a CP short circuit, a PP short circuit and a PP break.
The tester can also simulate an AC insulation fault of 2.5 kΩ from L1, L2 or L3 to protective earth. This checks the station’s insulation-monitoring response.
The device does not validate the switch-off time. Users should therefore treat fault simulation as a functional check rather than a complete timing validation.
Clear troubleshooting workflow
The Easy Chester Micro evaluates safety and charging release as separate steps. This structure helps technicians diagnose a customer complaint such as “the charger is not charging.”
A technician can first check whether the station accepts the simulated vehicle states. The next step examines whether authorisation is present. Finally, the tester verifies whether voltage reaches the connector.
After a repair, technicians can reuse the same test settings. This enables a direct comparison between the result before and after intervention.
Test reports and documentation
Each charging point receives one PDF test report. The report states whether the test result is PASSED or FAILED.
It documents every measured value with its corresponding test step and explanation. It also includes the charging-communication sequence.
Reports contain voltage, current, maximum charging power, PLC MAC address and safety-test results. Users can add comments, address fields and a company logo.
With a mobile hotspot, technicians can email the report directly from the field. The optional maintenance package adds photographs and GPS-based test-location data.
What the device does not cover
The Easy Chester Micro is designed for AC wallboxes and AC charging stations. It does not test DC charging stations or CCS charging points.
It also does not perform an AC load test. TLS-protected communication is likewise outside its current test scope.
For teams that need DC coverage, comemso positions the Easy Chester Ultimate as the AC/DC alternative. The Ultimate supports DC charging tests and can apply a test load of up to 60 kW.
Key capabilities
- Combines installation testing, vehicle simulation and communication testing in one portable device.
- Supports IEC 61851-1, SAE J1772, ISO 15118-2 and ISO 15118-3 PLC communication.
- Tests AC charging release without requiring a customer vehicle or laptop.
- Offers optional grid-side and vehicle-side electrical-safety measurements.
- Simulates protective-conductor, CP and PP faults during charging.
- Creates a PDF report with measured values, communication steps and PLC data.
- Operates from USB-C power sources, including a suitable power bank.
- Supports over-the-air firmware updates and remote support through the optional maintenance package.
Practical value for service teams
The Easy Chester Micro addresses a common field-service problem: separating an electrical installation fault from a charging-communication failure. Its guided workflow makes both areas visible in one test sequence.
For installers, the device can support commissioning and periodic inspection. For service organisations, it can help document repairs and verify that a charger returns to normal operation.
Its portability, guided touchscreen workflow and combined reporting reduce the amount of equipment needed on site. However, teams working with DC infrastructure, load testing or TLS-secured sessions still need complementary tools or procedures.
Sources: comemso
