UFC ground fault

How it presents

Symptom

Delta UFC100 dispenser trips ground fault mid-session or during CableCheck, most often after rain, wash-down, or a recent cable service call. HMI banner reads Ground Fault while OCPP reports Faulted/GroundFailure; the fault can lock a single gun or take the whole cabinet Unavailable if the sensing sits upstream of the split.

Root causes (by observed frequency)

1. #1 Moisture bridging the ground-fault sensing path at the cable gland or holster

   Highest-frequency cause on outdoor UFC100 sites after rain or pressure washing; dries out and clears on its own if hardware is sound.

2. #2 Damaged cable jacket exposing conductor to a grounded surface

   Look for curb-scrape marks or crush points near the strain relief; swap to a known-good cable to confirm.

3. #3 High-impedance or open equipment ground/bonding at the UFC100 pedestal

   Measure PE continuity from cabinet frame to the site grounding electrode before condemning the GF board.

4. #4 GF sensing board drift or nuisance trip after firmware update

   Rare; only pursue after moisture and PE bonding are proven clean on both guns.

Diagnostic procedure

1. 1. Classify whether the trip follows one gun or the whole cabinet, and photograph the HMI banner plus connector ID for the ticket.

   Expected: Fault tag names a single connector vs. cabinet-wide GroundFailure

   Tools: phone camera, UFC100 local screen

2. 2. Dry the holster and cable path completely, then attempt a single reset before touching hardware.

   Expected: Fault clears and holds through one dry test session if moisture was the cause

   Tools: rags, dry compressed air

3. 3. Swap in a known-good UFC100 cable on the failing gun and retest CableCheck.

   Expected: Fault moves off the connector if the original cable is the cause; stays with the cabinet if not

   Tools: known-good DC cable

4. 4. Measure equipment ground continuity from the cabinet frame to the site grounding electrode.

   Expected: Under 1 Ω typical for a sound bond; higher readings point to a site grounding defect

   Tools: digital low-resistance ohmmeter (DLRO) or DMM

5. 5. If dry and known-good cable both fail, escalate to Delta's GF sensing service path with the evidence pack.

   Expected: OEM confirms GF board fault code and issues an RMA or field procedure

   Tools: Delta OEM service line

The fix

Clear moisture and prove the cable before touching the GF sensing board; do not spam-reset a wet fault.

• DC cable / gun assembly

  Match UFC100 cooled-cable spec; OEM-approved only

• Ground-fault sensing board

  Delta OEM part; order only after moisture and PE ruled out

1. Lock out and tag out the affected gun, then dry the holster, cable jacket, and any exposed connectors before attempting a reset, since resetting into standing moisture only re-trips the same protective device.
2. Swap the suspect cable for a known-good UFC100 cable and run CableCheck twice to confirm the fault clears when the original cable is removed from the circuit.
3. If the fault persists with a known-good cable, measure equipment ground continuity from the cabinet frame to the site grounding electrode and correct any high-impedance bonding found before replacing electronics.
4. Only after moisture and grounding are proven clean should the GF sensing board be replaced through Delta's OEM channel, and the unit must complete a full validation session before being returned to service.