ELEC ECAM Warnings — Summary

This article is the index to the whole electrical abnormal chapter. The dedicated articles (22 through 30) each take one failure family and work it in depth; this one stands above them and answers a different question — given any ELEC ECAM line, what is it, how serious is it, and which article handles it? It is a map, not a new mechanism: every trigger condition quoted here is treated verbatim in the article it routes to.

Counting the ELEC alerts is itself a small lesson. Reading the FCOM PRO-ABN-ELEC table of contents end to end (rather than searching for a few names) turns up about thirty independent warnings — and the count only comes out right if you read every entry, because some of the lightest items (ELEC BAT 1(2) SYS FAULT, ELEC APU BAT SYS FAULT) are easy to miss when skimming for the obvious bus failures. The point of an index is to make sure none of the thirty is forgotten, the trivial as much as the dramatic.

1. The severity terrain — one red warning in the whole chapter

The single most useful fact about the entire ELEC chapter is how flat its severity terrain is. Of the ~30 warnings, exactly one is a red WARNING — ELEC EMER CONFIG — which alone carries the continuous repetitive chime and LAND ASAP. Its trigger is the bottom of the ladder:

"This alert triggers when the main generators and all AC busbars are not supplied."

Per FCOM PRO-ABN-ELEC. Everything else — every generator fault, every bus loss, every transformer-rectifier latch-open — is an amber caution, a crew-awareness line, or a status memo. That is not an accident of presentation; it is the redundancy of the network showing through the ECAM. Two engine generators, an APU generator, an emergency generator and three batteries are arranged so that almost any single failure is silently covered by reconfiguration, and the crew is told about it at caution level. Only when the redundancy is exhausted — main generators and all AC buses gone — does the chapter turn red.

ELEC ECAM warnings  (~30, one chapter)
│
├─ RED WARNING (CRC + LAND ASAP) ── the only one ─────────────────► art. 29
│     ELEC EMER CONFIG   (2 branches: GEN/APU recovered | not recovered)
│
└─ AMBER CAUTION / crew-awareness / status memo ── all the rest
      ├─ Generation sources .... GEN / APU GEN / IDG / OVERLOAD ───► art. 22
      ├─ AC buses .............. AC BUS 1·2, AC ESS BUS ───────────► art. 23 / 24
      ├─ DC buses .............. DC BUS 1·2·1+2, DC BAT, DC ESS ───► art. 25 / 26
      ├─ Conversion & battery .. TR, STATIC INV, BAT ─────────────► art. 27
      ├─ Management & total loss ECMU, BUS TIE OFF, EMER CONFIG ──► art. 28 / 29
      └─ Monitoring ............ C/B TRIPPED, C/B MONITOR FAULT ──► art. 17

[!warning]- A single generator, bus or TR failure is never the red warning

It is tempting to read a dramatic line such as ELEC AC BUS 1 FAULT or ELEC DC BUS 1+2 FAULT as an emergency. It is not — it is an amber caution, because the network reconfigures around it. The chapter has exactly one red line, ELEC EMER CONFIG, and it requires the loss of all main AC: the main generators and every AC busbar. If you have any AC bus left, you are not in the emergency electrical configuration. Read the colour, not the drama.

2. The complete warning index — six families

The thirty warnings sort cleanly into six families, each routing to the article that handles it. Bus names use their FIN tags (1XP = AC BUS 1, 1PP = DC BUS 1, and so on, as established in the overview).

2.1 Family A — generation sources → Gen / IDG failures

Two of these triggers are worth fixing verbatim. The GEN pb logic:

"This alert triggers when the GEN 1(2) pb-sw is abnormally set to OFF."

The overload logic, which is exactly the "100 % and shedding could not recover it" rule:

"This alert triggers when the load of one generator is above 100% of rated output."

Per FCOM PRO-ABN-ELEC. The OVERLOAD line is shared across all three AC source types (engine generator / APU generator / external power), which is why its single ECAM title names all three.

2.2 Family B — AC buses → AC bus faults and AC ESS bus fault / shed

The bus-loss triggers are uniform — "the busbar is not supplied" — and the ALTN status line names its own abnormal source path:

"This alert triggers when the AC ESS BUS is abnormally supplied by AC 2 BUS."

Per FCOM PRO-ABN-ELEC. That is the placard half of the AC ESS FEED transfer: the bus has power, but from the alternate side, and it will not auto-return in flight.

2.3 Family C — DC buses → DC bus faults and DC ESS bus fault / shed

The DC bus triggers read identically to the AC ones:

"This alert triggers when the DC 1 and DC 2 busbars are not supplied."

Per FCOM PRO-ABN-ELEC. Note the asymmetry in level: ELEC DC BUS 1 FAULT is a crew-awareness line (its procedure is, verbatim, "Crew awareness.") because TR2 quietly restores 1PP through the DC tie — while ELEC DC BUS 2 FAULT is a full caution, because 2PP carries flight-control computers that must be commanded to stay on.

2.4 Family D — conversion and batteries → TR / battery faults / lithium fire

The two TR families behave differently in handling: a main/ESS TR latch-open is a pure power-loss caution, while an APU TR fault is handled by shedding the APU battery to stop further damage. That APU BAT — OFF step is the index's reminder that not every TR fault is the same procedure.

2.5 Family E — network management and total loss → ECMU fault and Emergency electrical configuration

"This alert triggers when the ECMU is failed."

Per FCOM PRO-ABN-ELEC. ELEC BUS TIE OFF is, like the two ALTN lines, a status placard rather than a fault — its procedure is "Crew awareness." — telling you the network corridor is open because the BUS TIE pb is OFF. The two ELEC EMER CONFIG branches differ only by whether a generator can be recovered (GEN 1 or/and GEN 2 recovered or APU GEN available) or not (GEN not recovered and APU GEN not available); both carry LAND ASAP, and both route to article 29.

2.6 Family F — monitoring → Circuit breakers / CBMU

The C/B TRIPPED reengagement rule is the one verbatim worth carrying out of this family, because there is no circuit-breaker panel in the cockpit and the discipline is in the procedure:

"Do not reengage a C/B that has tripped by itself, unless the Captain judges it necessary to do so for the safe continuation of the flight. This procedure should be adopted only as a last resort, and only one reengagement should be attempted. On ground, do not reengage the C/B of the fuel pump(s) of any tank."

Per FCOM PRO-ABN-ELEC. So the rule is not a flat "never" — it is "not unless the Captain judges it necessary, last resort, one attempt only, and never a tank fuel-pump breaker on the ground."

3. Three patterns for reading any ELEC warning

Across all thirty, three patterns recur. Hold these and you can place an unfamiliar ELEC line without opening its article.

1. The severity terrain is flat. Only ELEC EMER CONFIG is red (CRC + LAND ASAP); the rest are amber cautions, crew-awareness lines or status memos. The redundant network keeps almost every single failure at caution level — so a dramatic-sounding bus or generator line is, by design, not an emergency.

2. The status-placard family is not a fault. ELEC AC ESS BUS ALTN, ELEC DC BAT BUS ALTN, ELEC BUS TIE OFF and ELEC IDG 1(2) DISCONNECTED are not new failures — they are reminders that the system is in a non-default configuration. When one appears, the first move is to recall how it got there (a transfer you selected, a contactor a procedure opened, a disconnect you commanded), not to hunt for a fresh fault.

3. The crew-awareness lines mean "already handled, or nothing to do." ELEC DC BUS 1 FAULT, ELEC IDG 1(2) DISCONNECTED, ELEC BAT 1(2) or APU BAT OFF carry the bare "Crew awareness." procedure because the reconfiguration is already complete or no crew action is required. This is the caution-level face of the chapter's silent-reconfiguration character (see Automatic reconfiguration).

4. Scope and routing

This is an index article: it introduces no new mechanism. Each family routes to the article that carries the deep treatment and the verbatim procedures; the one-line triggers here are the same ones spelled out there. Two boundaries are worth stating:

• The lightweight items are real. ELEC BAT 1(2) SYS FAULT, ELEC APU BAT SYS FAULT, ELEC DC BAT BUS ALTN and the other crew-awareness lines have minimal procedures — but they exist in the main library and belong on the map. Reading the full PRO-ABN-ELEC contents (not skimming for the obvious bus failures) is what keeps them from dropping off the count.
• Dispatch is not here. This article stays inside the in-flight ECAM view. The "can I sign it out?" question — which ELEC fault is no-go, Category C go, or outside the MEL coordinate system — is concentrated in MEL dispatch view. The previous article, Battery-only flight, closes the degradation ladder that this index summarises.

Self-test

[!note]- Q1. Of the ~30 ELEC ECAM warnings, how many are red, which one(s), and what is the trigger?

Exactly one: ELEC EMER CONFIG (in two branches — generator recoverable, or not). It is the only red WARNING in the chapter, carrying the continuous repetitive chime and LAND ASAP. Its trigger, verbatim, is "the main generators and all AC busbars are not supplied." Every other ELEC warning — generator faults, bus losses, TR latch-opens, battery faults — is an amber caution, a crew-awareness line, or a status memo. The flat severity terrain is the network's redundancy showing through the ECAM.

[!note]- Q2. Name the "status-placard" family and explain what they are telling you.

ELEC AC ESS BUS ALTN, ELEC DC BAT BUS ALTN, ELEC BUS TIE OFF, and ELEC IDG 1(2) DISCONNECTED. They are not new faults — they report that the system is in a non-default configuration. AC ESS BUS ALTN means AC ESS is "abnormally supplied by AC 2 BUS" (the ALTN feed selected, no auto-return in flight); DC BAT BUS ALTN means 3PP is on its 1PC2 alternate path; BUS TIE OFF means the corridor is open because the pb is OFF; IDG DISCONNECTED means you commanded a disconnect. The first reaction to any of them is to recall how it got there.

[!note]- Q3. Why is ELEC DC BUS 1 FAULT only crew-awareness while ELEC DC BUS 2 FAULT is a full caution?

Both triggers are "the DC busbar is not supplied." But 1PP (DC BUS 1) is quietly restored by TR2 through the DC tie, so the reconfiguration is already complete — its procedure is the bare "Crew awareness." 2PP (DC BUS 2), by contrast, carries flight-control computers, so its loss demands an action (SEC 2 KEEP ON) and rates a full caution. Same wording, different consequence — the level encodes whether anything is left for the crew to do.

[!note]- Q4. Distinguish AC ESS BUS FAULT, AC ESS BUS SHED and AC ESS BUS ALTN.

ELEC AC ESS BUS FAULT — 9XP (the AC ESS bus itself) is not supplied; recovered by selecting AC ESS FEED ALTN, which feeds AC ESS from AC BUS 2. ELEC AC ESS BUS SHED — the AC SHED ESS BUS (4XP, with 401XP as its sub-segment) is not supplied; the first decision is whether this is a designed shed or a genuine sub-segment fault. ELEC AC ESS BUS ALTN — a status placard, not a fault: AC ESS is currently fed in the alternate path (from AC BUS 2). FAULT and SHED are failures of different buses in the essential family; ALTN is the configuration memo that follows the feed transfer.

[!note]- Q5. You see an unfamiliar ELEC ... line in the cruise. How do you place it without opening its article?

Apply the three patterns. (1) Read the colour: if it is not red, it is not the emergency configuration — a single failure the network has covered. (2) Check whether it is a status placard (ALTN / BUS TIE OFF / DISCONNECTED) — if so, recall how the configuration was reached rather than hunting a new fault. (3) If its procedure is "Crew awareness.", the reconfiguration is done or nothing is required. Then route by family: generation → article 22, AC buses → 23/24, DC buses → 25/26, conversion/battery → 27, management/total loss → 28/29, monitoring → 17.

Key takeaways

References

Per FCOM PRO-ABN-ELEC (the complete ELEC abnormal-and-emergency chapter, p.3339–3416, rev 14 JAN 26 — read end to end via its table of contents so the lightweight items are not lost), covering the ~30 ELEC ECAM alerts, their triggering conditions (bus "not supplied" lines, the OVERLOAD 100 % rule, the GEN-OFF and AC ESS BUS ALTN logic, the EMER CONFIG red trigger, the ECMU and IDG OIL SYS FAULT triggers, the crew-awareness lines, and the C/B TRIPPED reengagement note); QRH 16.01A / 16.02A (ELEC EMER CONFIG summaries) and 24.05A. The trigger conditions are treated verbatim in the dedicated articles: Gen / IDG failures, AC bus faults, AC ESS bus fault / shed, DC bus faults, DC ESS bus fault / shed, TR / battery faults / lithium fire, ECMU fault, Emergency electrical configuration, and Circuit breakers / CBMU; the dispatch view is in MEL dispatch. The six-family grouping and the three reading patterns are an integrative synthesis of the above and add no facts from outside the library.

Independent study material, not an Airbus publication. Refer to current operator FCOM, FCTM, and QRH for operational use.