Wallbox, EVSE, and Charging Cable Testers and Test Adapters

Frequently Asked Questions About Wallbox, EVSE, and Charging Cable Inspections

Wall boxes, charging stations, and charging cables together form the interface between the electrical installation and the electric vehicle. To ensure a proper inspection, electrical safety, vehicle communication, and functionality must be considered separately. The following questions explain the most important terms and testing procedures related to EVSE, Mode 3, Type 2, Control Pilot, and Proximity Pilot.

• What does EVSE stand for?

  EVSE stands for Electric Vehicle Supply Equipment.

  This term refers to the electrical equipment that connects an electric vehicle to the power supply and enables or controls the charging process safely.

  Examples include:

  • wallboxes
  • AC charging stations
  • other permanently installed charging devices

  A wallbox is therefore a type of EVSE.

• What is the difference between a wallbox and an EVSE?

  “Wallbox” typically refers to a compact charging device mounted on a wall or similar structure.

  EVSE is the broader technical term and generally encompasses all electric charging devices for electric vehicles.

  For testing purposes, both terms are often used interchangeably.

• What is Mode 3 when charging an electric car?

  Mode 3 refers to a wired AC charging method in which the electric vehicle is connected to the AC power grid via a charging device specifically designed for this purpose.
  
  Control and status information is exchanged between the vehicle and the EVSE via the corresponding signal lines.
  
  In Europe, Type 2 connectors are frequently used in Mode 3 charging systems.

• What is a Type 2 plug?

  Type 2 is a standardized connector system for AC charging of electric vehicles.

  In addition to the contacts for electrical power and the ground wire, the connector also has contacts for the Control Pilot (CP) and Proximity Pilot (PP) signals.

  Type 2 connector systems are used in many European electric vehicles, wall boxes, and AC charging stations.

• What is an EVSE test adapter?

  An EVSE test adapter establishes a defined electrical interface between a wallbox or charging station and a suitable installation or safety testing device.
  
  It can also simulate certain conditions of a connected electric vehicle or charging cable.
  
  This allows a wallbox to be tested without having to use an actual electric vehicle for every test.

• Is the A 1532 XA itself a complete wallbox tester?

  No.

  The A 1532 XA is an EVSE test adapter.

  It is used in conjunction with a compatible installation tester to perform comprehensive electrical safety tests.

  The adapter connects to the EVSE and enables, among other things, vehicle and cable simulations, measurement connections, and certain functional and fault simulations.

• What can be tested with the Metrel A 1532 XA?

  When used with supported Metrel installation testers, the A 1532 XA enables electrical safety and functional tests on Mode 3 EVSEs with Type 2 connectors.

  Supported functions include, among others:

  • Simulation of various vehicle states
  • Simulation of different cable conditions or current-carrying capacities
  • Access to L1, L2, L3, N, and PE
  • CP signal monitoring
  • Support for RCD tests
  • Load tests up to 13 A
  • Various fault simulations
  • Automated test sequences with compatible testers
• Can a wallbox be tested without connecting an electric car?

  Yes.
  
  This is precisely one of the key functions of an EVSE test adapter.
  
  The A 1532 XA can simulate various states of an electric vehicle. This allows you to test how the wallbox responds to the corresponding vehicle states.

• What does vehicle simulation mean in the context of a wallbox test?

  An EVSE expects certain electrical signals from the connected vehicle.

  A test adapter replicates these conditions in a defined manner.

  This makes it possible, for example, to simulate whether:

  • no vehicle is connected,
  • a vehicle is connected,
  • the vehicle is ready to charge,
  • or an error condition exists.

  This allows the EVSE's response to be tested in a targeted manner.

• What is the CP signal?

  CP stands for Control Pilot.

  In Mode 3 charging systems, the Control Pilot line is used for control and signaling between the electric vehicle and the charging station.

  Among other things, the CP signal can be used to detect or communicate various vehicle and charging states.

• What CP states can be simulated during an EVSE test?

  Using a suitable test adapter, various conditions can be simulated.

  These include, for example:

  • Vehicle not connected
  • Vehicle connected
  • Vehicle connected and ready to charge
  • Vehicle with special ventilation requirements
  • Pilot or error condition

  This allows you to verify whether the wallbox responds appropriately.

• What does PP, or Proximity Pilot, mean?

  PP stands for Proximity Pilot.

  One of the functions of PP is to detect the presence and characteristics of the connected charging cable.

  For example, resistance coding can be used to indicate a charging cable's permissible current-carrying capacity.

• Why is the PP resistor tested?

  The PP coding resistor contains information about the charging cable's current-carrying capacity.
  
  Incorrect resistor coding can therefore prevent the cable and charging device from working together properly.
  
  During a professional charging cable inspection, the PP resistor can therefore be measured specifically.

• Can the A 1532 XA simulate different charging cables?

  Yes.
  
  The adapter has a selector switch for the Proximity Pilot function.
  
  This allows you to simulate different cable conditions or current-carrying capacities.
  
  The EVSE can thus be tested according to its intended behavior.

• Can a PE error be simulated using the A 1532 XA?

  Yes.

  The XA version supports various fault simulations.

  These include, among others:

  • PE open
  • PE-CP short circuit
  • Diode short circuit

  Such simulations make it possible to verify the charging device's response to defined fault conditions.

• Why are faults simulated on a wallbox?

  A safety and functional test should not only demonstrate that a system operates under normal conditions.
  
  Depending on the test equipment and test procedure, it is also possible to verify how the EVSE responds to specific, defined error conditions.
  
  An EVSE test adapter makes it possible to simulate such conditions in a controlled manner.

• Can a 6-mA DC residual current device be tested using the A 1532 XA?

  When used with appropriate test equipment, the A 1532 XA supports the corresponding tests of EV-RCD functions and 6-mA DC fault current detection.
  
  Which test can actually be performed depends on the connected installation tester and the EVSE being tested.

• What is an RCD in a wallbox?

  RCD stands for Residual Current Device, commonly referred to in German as a residual current protection device or FI switch.

  This protective function is designed to detect certain residual currents and shut down the electrical system accordingly.

  Which residual current protection devices are required or installed for a specific charging station depends on the installation, the wallbox, and the relevant technical specifications.

• What electrical measurements may be required during a wallbox inspection?

  Depending on the system, the reason for the test, and technical specifications, the following may be relevant, among other things:

  • Protective conductor continuity
  • Insulation resistance
  • Loop or network impedance
  • RCD test
  • Voltage and phases
  • Safety Measures
  • Functional Test of the Charging Equipment

  The EVSE test adapter provides the interface to the wallbox for this purpose. The actual measurements are performed using a suitable installation tester.

• What is the difference between a safety inspection and a functional test of a wallbox?

  During an electrical safety inspection, the protective measures and electrical characteristics of the system are examined.

  During a functional test, on the other hand, the EVSE is checked to ensure it responds properly to various vehicle, cable, and charging conditions.

  Both types of testing may be relevant for a comprehensive assessment.

• Can the Control Pilot history be measured?

  Yes.
  
  The A 1532 XA has a BNC output for monitoring the CP signal.
  
  Using a suitable measuring instrument or oscilloscope, you can analyze the signal waveform.

• Is a wallbox inspection the same as an inspection of the electric vehicle?

  No.

  During a wallbox or EVSE inspection, the charging device is inspected.

  In contrast, a high-voltage electrical safety inspection examines the vehicle or its high-voltage system.

  You can find suitable test equipment for vehicle measurements under HV Safety and Electrical Inspections for Electric Vehicles.

• What is a Mode 3 charging cable?

  A Mode 3 charging cable connects an electric vehicle to a designated AC charging station.
  
  In addition to the current-carrying conductors and the ground wire, the cable also contains the CP and PP connections—or coding—required for the charging function.

• Why should a Mode 3 charging cable be tested?

  Charging cables are subject to mechanical and electrical stress.

  Potential faults can occur, for example, in:

  • Plugs
  • Contacts
  • Cable jacket
  • Conductors
  • Protective conductor
  • CP wire
  • PP coding

  An electrical test can help identify such faults.

• What is the Metrel A 1832?

  The A 1832 is a test adapter for Mode 3 charging cables with Type 2 connectors.

  It serves as the interface between the charging cable and a suitable safety tester.

  This allows various electrical safety and functional tests to be performed on the charging cable.

• Is the A 1832 a standalone charging cable tester?

  No.

  The A 1832 is a charging cable test adapter.

  A compatible Metrel device or other suitable safety tester is required to perform the actual electrical measurements.

• What tests can be performed with the A 1832?

  When used with a suitable tester, the following can be tested, among other things:

  • Continuity of the protective conductor (PE)
  • Continuity of L1, L2, L3, and N
  • Continuity of the CP line
  • PP coding resistor
  • Insulation of the outer conductors against ground

  In addition, the adapter features LED indicators for a quick continuity check of the power conductors.

• Can the protective conductor connection of a charging cable be tested?

  Yes.
  
  The continuity—or low-resistance state—of the protective conductor is one of the most important electrical tests for a Mode 3 charging cable.
  
  The A 1832 enables this measurement when used in conjunction with a suitable safety tester.

• Can all conductors in a Mode 3 cable be tested?

  With the A 1832, in addition to the ground wire, you can also check the continuity of:

  • L1
  • L2
  • L3
  • N
  • CP

  This is important because a cable can have a fault in one conductor even if the ground wire is intact.

• Can the insulation resistance of a charging cable be tested?

  Yes.
  
  When used with an appropriate safety testing device, insulation measurements can be performed between the designated conductors or against the protective conductor.
  
  The test parameters must be compatible with the charging cable and the applicable test specifications.

• Can you tell the difference between 13-, 20-, 32-, and 63-A charging cables?

  The maximum current capacity of a Mode 3 charging cable is indicated by the PP resistance code.
  
  The A 1832 can be used to measure this coding resistor and thus verify whether the code matches the intended charging cable.

• Can the A 1832 document test results?

  When used with compatible Metrel testers and the corresponding software, automated test sequences can be run and professional test reports can be generated.
  
  This makes the solution particularly well-suited for recurring and standardized charging cable tests.

• What is the difference between the A 1532 XA and the A 1832?

  The two adapters test different parts of the charging system.

  A 1532 XA:
  Tests or simulates functions on the wallbox / EVSE.

  A 1832:
  Used to perform electrical testing of the Mode 3 charging cable.

  This allows the charging station and charging cable to be tested separately.

• What is the A 1631 EV monitoring cable?

  The A 1631 is a specialized measurement and monitoring cable used between an EVSE and an electric vehicle.
  
  It features Type 2 connectors for connecting to the vehicle and the charging station.
  
  When used with appropriate measuring devices or adapters, it allows electrical parameters to be analyzed during an actual AC charging process.

• What can be monitored with the A 1631 during a charging process?

  Depending on the additional Metrel devices used, the following parameters, among others, can be analyzed:

  • Current
  • Voltage
  • PP resistance
  • CP signal communication

  This distinguishes the A 1631 from a pure EVSE simulation.

• What is the maximum charging current for the A 1631?

  The A 1631 is designed to monitor AC charging processes with EVSEs up to 32 A.

  For actual measurements, the limit values and specifications of the connected measuring devices must also be taken into account.

• Can the A 1631 measure the actual charging current?

  The A 1631 provides the necessary measurement ports for monitoring the charging current.
  
  A suitable measuring device is connected to perform the actual measurement or verification.
  
  The monitoring cable itself does not replace a full-featured power or power quality meter.

• Can the A 1631 be used to measure the charging voltage?

  Yes, when used with a suitable measuring device, the voltage can be measured or checked during the AC charging process.
  
  The A 1631 provides the necessary measurement terminals for this purpose.

• Can the A 1631 be used to analyze communication between the vehicle and the wallbox?

  The A 1631 is designed to monitor CP signal communication during an actual charging process.
  
  This function requires additional compatible Metrel testers or the designated eMobility Analyzer.
  
  The A 1631 alone does not fully analyze CP communication.

• Why is it useful to analyze an actual charging process?

  Some errors only occur when the vehicle and the charging device are actually connected and energy is being transferred.

  A measurement taken during an actual charging process can therefore provide additional information, such as:

  • Charging current
  • Voltage
  • CP communication
  • PP encoding
  • Behavior of the EV and EVSE
• Can the A 1631 be used to simulate an external load?

  Yes.

  An external load of up to 13 A can be simulated using the appropriate connections.

  This can be used, for example, to test an EVSE's consumption tracking or metering function.

• Can these devices also be used to test DC fast charging?

  The devices described here—the A 1532 XA, A 1832, and A 1631—are designed for AC/Mode 3 and Type 2 applications, respectively.

  DC fast-charging systems and Mode 4 systems have different technical requirements and necessitate dedicated test and measurement procedures.

• Is Type 2 the same as CCS?

  No.
  
  Type 2 describes the connector interface used in AC charging systems.
  
  CCS, or the Combined Charging System, expands the connector system for DC fast charging by adding additional power contacts.
  
  The Metrel products discussed here are primarily designed for Type 2/Mode 3 AC applications.

• How often does a wallbox need to be inspected?

  It is not possible to specify a universal inspection interval for every wallbox.

  The type of inspection and inspection interval may depend, among other things, on:

  • Type of installation
  • Operator
  • Usage
  • Risk assessment
  • Manufacturer’s specifications
  • Applicable legal and technical requirements

  The applicable requirements must therefore be determined for the specific system.

• Should a wallbox be inspected after installation?

  A newly installed or modified electrical system must be tested in accordance with the applicable requirements.
  
  or an EVSE, this includes both standard electrical installation tests and charging-function-specific tests, depending on the installation.
  
  An EVSE adapter allows a suitable installation tester to be connected to the charging station.

• Should a wallbox be inspected again after repairs?

  The tests required after a repair depend on the type and scope of the work performed.
  
  If safety- or function-related parts were involved, corresponding retests or functional tests may be required.
  
  The specific procedure is based on the manufacturer’s specifications and the relevant technical requirements.

• Can a standard multimeter replace a wallbox test?

  No.

  A multimeter can be used to measure individual parameters such as voltage or resistance.

  However, a complete EVSE test may require additional tests and simulations, such as:

  • RCD test
  • Insulation test
  • Loop impedance
  • Vehicle status simulation
  • CP/PP function test
  • Fault simulation

  Suitable installation testers and EVSE test adapters are used for this purpose.

• Can an electric vehicle be used as a substitute for an EVSE test adapter?

  A real vehicle can demonstrate whether a charging process works in principle.
  
  However, it does not allow for targeted and reproducible simulation of various vehicle, cable, and fault conditions.
  
  For professional testing, an EVSE test adapter therefore offers significantly more defined testing options.

• What is the difference between the A 1532 XA and the A 1631?

  The A 1532 XA simulates an electric vehicle and is used for targeted testing of the EVSE.

  The A 1631, on the other hand, is used during an actual charging process between the EVSE and a real electric vehicle.

  To put it simply:

  A 1532 XA → The vehicle is simulated.

  A 1631 → A real vehicle is charging, and the charging process is monitored.

  Which solution do I need for which testing task?

  The key factor in making a selection is what needs to be tested:

  Testing a wallbox or EVSE:
  A 1532 XA with a compatible installation tester.

  Testing a Mode 3 Type 2 charging cable:
  A 1832 with a suitable safety tester.

  Analyzing an actual AC charging process:
  A 1631 with the measuring instruments or Metrel components suitable for the desired measurement.

• Who is authorized to perform electrical inspections on wall boxes and EVSEs?

  Electrical inspections of charging equipment may only be performed by persons who are appropriately qualified and authorized for the specific task.
  
  The required qualifications depend on the measurement, the system, the work environment, and the applicable electrical specifications.
  
  The qualifications required for work on a wallbox must be distinguished from those required for work on a vehicle’s high-voltage system.

• Is a wallbox inspection part of the high-voltage vehicle diagnostic test?

  No.

  A wallbox is part of the electrical charging infrastructure separate from the vehicle's high-voltage system.

  For this reason, the wallbox/EVSE testing section should be listed as its own topic area on the Leitenberger website.

  For electrical tests performed directly on the vehicle, see HV Safety and Electrical Tests on Electric Vehicles.

• What other e-mobility testing services does Leitenberger offer?

  In addition to charging infrastructure, Leitenberger offers specialized solutions for, among other things:

  • HV battery diagnostics and state-of-health (SoH) testing (SoH)
  • Leak testing of HV batteries and high-voltage components
  • Thermal management and coolant testing equipment for electric vehicles
  • HV safety and electrical testing of electric vehicles

  This covers key testing and service tasks related to electric and hybrid vehicles as well as their charging infrastructure.