This is a frustrating problem, and common enough with EVs and EVSEs to warrant some troubleshooting steps beyond just verifying output voltage. Here's a breakdown of possible causes and troubleshooting steps, drawing on common EVSE tech experiences

Understanding the Problem:

The fact that the charger powers on, shows proper voltage, but then immediately shuts off upon connection suggests the issue isn't a total failure, but rather a communication or safety protocol being triggered. The EVSE is detecting something it doesn't like and is aborting the charging session. Since there's no card reader, it rules out payment-related issues.

Troubleshooting Steps

1.

Start with the Basics (Even if you think you've checked them)



Grounding

A poor ground is a major suspect. Verify the ground wire from the EVSE to the electrical panel is properly sized, tightly connected, and free of corrosion. Test ground continuity. A faulty ground can create all sorts of phantom issues.

Wiring Connections (Inside the EVSE and the vehicle connector)

Open the EVSE (after disconnecting power, of course!) and inspect all wiring connections. Look for loose connections, burned wires, or signs of overheating. Check the wiring to the vehicle connector as well. Loose or damaged wiring can create voltage drops and communication errors.

Input Voltage

Confirm the EVSE is receiving the correct input voltage. Voltage sag under load can cause issues. Use a multimeter to check the voltage at the EVSE's input terminals while it's attempting to charge. Compare it to the expected voltage.

Circuit Breaker

Make sure the circuit breaker supplying the EVSE is the correct amperage and is in good working order. Try replacing the breaker as a troubleshooting step.

Clean the J1772 Connector

A dirty or corroded J1772 connector (the one that plugs into the car) can cause communication problems. Clean the pins with electrical contact cleaner and a small brush. Check for bent or damaged pins.2.

Isolate the Problem



Test with Multiple Vehicles

The most important step! If you've only tested with one vehicle, the problem might be with that specific vehicle's charging system, not the EVSE. Try testing with at least 2-3 different EV models. If it only fails with one specific car, the problem is almost certainly with the car.

Test Multiple EVSEs with the Same Vehicle

If you have access to other EVSEs (even different brands), try charging the problem vehicles with those chargers. This helps determine if the problem is truly specific to these four Leviton units.

Test at Different Locations

Bring one of the problem EVSEs to a completely different electrical location and try it with a known-good vehicle. This helps rule out issues with the site's electrical infrastructure.3.

Focus on Communication Signals (Pilot Signal/Proximity Detection)



Pilot Signal (PWM)

The J1772 standard uses a pulse-width modulated (PWM) signal on the pilot wire to communicate the maximum current the EVSE can deliver to the vehicle. A malfunctioning pilot signal can cause the EV to reject the charge. You'll need an oscilloscope to properly analyze the PWM signal. Look for: Correct frequency (typically 1 kHz) Correct duty cycle (this represents the available current) Clean signal (no excessive noise or distortion)

Proximity Detection (PP)

The Proximity Pilot (PP) pin is a resistor circuit that tells the EVSE that a cable is plugged in. The resistor value can indicate the cable's current carrying capacity. If the EVSE isn't properly detecting the cable, or is misinterpreting the cable's current rating, it might shut down. Inspect the PP resistor circuit inside the EVSE and the vehicle connector. Check the resistor value with a multimeter.4.

Safety Circuits and Fault Detection



Ground Fault Detection

EVSEs have ground fault detection circuits to protect against dangerous current leakage. These can be overly sensitive, especially in older installations. If the grounding is even slightly imperfect, a ground fault could trigger a shutdown. Check the EVSE manual for any troubleshooting steps related to ground fault detection. Some EVSEs allow you to temporarily disable (or reduce the sensitivity of) ground fault detection for testing purposes only.

Important: Never operate an EVSE with ground fault detection disabled unless you are a qualified technician performing diagnostics. Over-Current Protection

Although the EVSE should be communicating the current limit to the vehicle, a faulty over-current protection circuit could be tripping prematurely. This is less likely if the voltage is correct, but still worth considering.

Temperature Sensors

Some EVSEs have temperature sensors in the charging cable and internal components. If a sensor is faulty and reporting an abnormally high temperature, the EVSE might shut down.5.

Software and Firmware



Firmware Update

Check if there's a firmware update available for the EVSE. Bugs in the firmware can cause unexpected behavior. Contact Leviton support (again!) and specifically ask about firmware updates and known issues.

Configuration Settings

Some EVSEs have configuration settings that can be adjusted (e.g., maximum current output, ground fault detection sensitivity). Make sure these settings are appropriate for the vehicles being charged and the electrical installation.6.

Advanced Diagnostics (Requires Specialized Equipment)



CAN Bus Analysis

The EV and EVSE communicate over a CAN bus. A CAN bus analyzer can capture and decode the messages being exchanged, which can provide valuable insights into communication problems. This is usually beyond the scope of field troubleshooting but might be necessary if all other avenues are exhausted.

Specific Things to Ask Leviton

"We've verified proper output voltage, but the unit shuts down immediately upon connection. What are the known causes for this specific behavior?" "Are there any diagnostic codes or error logs that can be accessed to help identify the problem?" "Are there any specific troubleshooting procedures for ground fault detection or pilot signal issues?" "Are there any known compatibility issues with specific EV models?" "Can you provide detailed schematics or service manuals for this model of EVSE?" "Has there been any recent recalls or service bulletins related to this issue?"

Important Safety Considerations



Always disconnect power to the EVSE before opening it for inspection. Work with a qualified electrician if you are not comfortable working with electrical wiring. Follow all safety precautions outlined in the EVSE manual.If All Else Fails



Escalate the issue with Leviton

Be persistent. Speak to a higher-level support technician or a product specialist.

Consider replacement: If the EVSEs are truly new and Leviton can't provide a solution, consider demanding a replacement. Four malfunctioning units strongly suggests a manufacturing defect or a design flaw.By systematically working through these troubleshooting steps, you should be able to identify the cause of the problem and either fix it or provide Leviton with the information they need to resolve the issue. Good luck! Flag for review