Delta

Delta — field brand hub

Delta tickets in this corpus center on UFC-class DC fast chargers. Ground fault, backend unreachable, exhaust fan faults, and connector lock motor failures dominate. Verify grid and fan path before isolation-style RMAs, and split soft-offline backend from true protective GF. Name UFC and whether the stall is alone or pad-wide before opening HV.

When this OEM shows up / cabinet vs dispenser

UFC packages combine power conversion, cooling/exhaust, connector lock, and OCPP/backend connectivity. Ownership:

Protective / PE side: Ground fault under rain or wash-down—dry and prove PE before board swaps.

Thermal / airflow side: Exhaust fan fault driving derate or Faulted—filters and fan hardware before sensor theater.

Lock / connector side: Lock motor fail at Preparing—mechanical debris vs actuator.

Backend / network side: Backend unreachable with local Ready possible—DNS/TLS/CSMS path, not a power module.

Do not treat backend unreachable as “charger dead” without Heartbeat evidence. Do not clear GF repeatedly into a wet fault.

How faults typically present

HMI

• UFC banners (DEL-UFC-*).
• GF latch that returns immediately after clear.
• Fan fault / overtemp derate before hard Faulted.
• Lock fail with gun not seating.

OCPP / backend

• Faulted GroundFailure—use /guides/ocpp-faulted-triage.
• Soft-offline: Heartbeat timeout / Unavailable while local may look Ready (/entries/protocol-ocpp-f02-heartbeat-timeout-to-csms).
• DNS/TLS path: /entries/protocol-net-c01-dns-resolution-failure-to-csms.
• Modem RSSI in metal cabinets: /entries/sierra-wireless-mdm-rssi-rssi-too-low-in-cabinet.

Physical cues

• Wet holster after rain, blocked exhaust, grinding lock motor, antenna inside shielded door, recent SIM swap.

Ranked common failure patterns

1. UFC ground fault — Moisture bridging GF sensing or true PE fault. Free sample: /entries/delta-del-ufc-gf-ufc-ground-fault. PE continuity: /entries/protocol-gnd-01-ground-continuity-fail-at-dispenser.

2. Backend unreachable — CSMS/DNS/TLS/modem path; energy hardware may be fine. Free sample: /entries/delta-del-ufc-com-backend-unreachable. Prove Heartbeat and URL/certs before power-stage blame.

3. Exhaust fan fault — Filter, seized fan, or sensor. Entry: /entries/delta-del-ufc-fan-exhaust-fan-fault. Thermal siblings: /entries/protocol-temp-01-connector-overtemp-derate when derate presents at the gun.

4. Connector lock motor fail — Debris, ice, worn actuator, or feedback switch—second vehicle before board RMA. Entry: /entries/delta-del-ufc-lock-connector-lock-motor-fail. CCS latch cousins: /guides/ccs-handshake-basics.

Log sources / tools

Source	What you pull
UFC HMI / LEDs	GF, fan, lock, backend status
OCPP / CSMS	Heartbeat gaps, StatusNotification, BootNotification
Modem / ALEOS if present	RSSI/RSRP vs disconnect times
DMM / known-good cable	PE, lock continuity, isolation if ISO also present

Field checklist (first 15 minutes)

1. Photo HMI + connector ID; one stall or whole pad?
2. GF vs backend vs fan vs lock—name the branch.
3. Weather / wash-down / recent SIM or antenna work?
4. If GF: dry; PE measure; one clear after cause—not spam resets.
5. If backend: Heartbeat, DNS, TLS, RSSI before module crates.
6. If fan: inlet/exhaust clear; listen for seize.
7. If lock: inspect tongue; second vehicle; then actuator path.

When to escalate

Electrician — Open PE, feeder GF upstream, undervoltage clusters (/guides/site-power-quality-basics).

Network / CSMS — Backend unreachable with healthy RF after antenna prove; wrong OCPP identity after board work.

Delta OEM — Confirmed GF board after dry/PE; fan assembly after airflow proven; lock motor after mechanical prove.

Do not escalate soft-offline as GF, or lock fail as a power-module fault. Payment-only issues belong to PED (/guides/metering-payment), not UFC exhaust fans.

Worked examples

Example A — GF under rain, returns after clear. Dry holster/cable; measure PE. One OEM clear after cause—not ten resets.

Example B — Cloud red, local Ready, fan quiet OK. Backend unreachable / Heartbeat path. Check DNS, TLS, modem RSSI before exhaust-fan RMA.

Example C — Derate then fan fault banner. Clear filters; confirm fan spin. Do not megger for isolation first.

Example D — Lock motor grind at Preparing; second car same. Actuator/debris. Peer connector healthy means not “whole UFC dead.”

False friends

Looks like	Often actually
Dead power stage	Soft-offline backend
Isolation board	GF moisture / PE open
SECC fail	Lock motor mechanical
Antenna bad	Wrong OCPP URL after board swap

Related learning

/learn/reading-ocpp-statusnotification · /learn/safety-loto-boundary · /help

Ticket hygiene

Capture: HMI photo, connector/port ID, peer status, OCPP errorCode + vendor string verbatim, weather/service notes, and (for thermal/grid) a loaded measurement. Scrub customer PII before /request or Pro Q&A. Prefer one branch per ticket—do not merge money-path and HV into one RMA narrative.

Coordination notes

When opening OEM or electrician tickets, attach: HMI photos, connector IDs, OCPP vendor strings, peer-stall status, and any loaded voltage or RF measurements. That evidence pack cuts “replace module” ping-pong. Keep one fault branch per work order.

Platform notes (UFC)

UFC soft-offline is easy to misread as a dead power stage because Cloud is red. Always ask whether local Ready and whether a local start still works. Exhaust paths clog after storms and cottonwood season—fan faults spike then. Lock motors fail more in freezing rain than in dry heat. GF clears that return in under a minute are hard latches: stop resetting and measure PE. Pair backend tickets with modem RSSI history when the cabinet is metal.