Ground fault trip under rain

How it presents

Display

Ground fault trip under rain

OCPP

Faulted (StatusNotification) — capture errorCode/info

Symptom

Ground fault trip under rain on chargepoint (express-250): ChargePoint station HMI / Cloud diagnostics shows CP-E250-GF. Techs see session abort or stall Unavailable until the ranked cause is cleared. Correlate ChargePoint Cloud session + station event log before opening the cabinet.

Root causes (by observed frequency)

1. #1 Moisture or contamination bridging ground-fault sensing on CP-E250-GF

   Rain, wash-down, or failed cable boot seals rank highest on outdoor DCFC

2. #2 True equipment ground path open or high-impedance bond at pedestal
3. #3 Nuisance trip from EMI / filter aging after power-module work

Diagnostic procedure

1. 1. Capture ChargePoint station HMI / Cloud diagnostics message for CP-E250-GF, connector ID, and last successful session time

   Expected: Exact display string + OCPP status/errorInfo if present

   Tools: phone photos (scrubbed), CSMS

2. 2. Pull ChargePoint Cloud session + station event log; confirm whether Ground fault trip under rain follows one gun, one cabinet, or the whole site

   Expected: Fault correlates to one path

   Tools: CSMS export, OEM cloud

3. 3. On model express-250 hardware, isolate power quality / protective devices before opening HV for CP-E250-GF

   Expected: Voltage in band; no unexpected trips

   Tools: DMM, IR gun, LOTO kit

4. 4. Execute rank-1 cause check for “Ground fault trip under rain”; swap known-good cable/gun or stall if available

   Expected: Fault moves with cable or stays with cabinet

   Tools: known-good cable, IR, OEM service menu

5. 5. If unresolved, escalate with CP-E250-GF evidence pack (HMI photo, OCPP snippet, readings) — Express power cabinet vs dispenser split — confirm which side owns the code

   Tools: ticket template

The fix

Clear CP-E250-GF (Ground fault trip under rain) by correcting the ranked cause on chargepoint / express-250, then run a full validation session.

• Suspect module or controller indicated by rank-1 cause

  OEM chargepoint service channel; keep serial for RMA

  CP-E250-GF

1. LOTO and verify zero energy per chargepoint HV procedure before any bus work
2. Correct rank-1 cause for CP-E250-GF; do not shotgun-replace modules
3. Clear fault latches in HMI/CSMS; confirm StatusNotification returns to Available/Preparing as appropriate
4. Run validation: authorize → handshake → ≥5 minutes energy → clean stop; capture MeterValues
5. Document firmware, part lots, and scrubbed HMI photos for confirmations