Engine Room PLC Card Replacement — Kongsberg K-Chief Walk-through
How an ETO actually swaps a faulty Kongsberg K-Chief 700 or 600 module live, what to back up first, and the verification routine the chief engineer signs off.
Before you touch a card, back up the configuration
A Kongsberg K-Chief 700 cabinet (the post-2010 monitoring/automation standard on most bulkers and tankers) does not retain its application program across a card swap unless you have an export of the configuration on a service laptop. The K-Chief Configuration Tool reads the controller, dumps the active configuration to a .cfg file, and timestamps it. Do this before you touch anything — including before you measure with a multimeter near energised terminals. We have lost two days on board because an enthusiastic third engineer pulled an AS-controller before the dump and the project file on the office laptop was three months stale.
Praxis Selma owners — same principle, different tool. The Praxis configuration export is from the Selma Studio with the cabinet still energised and communicating. K-Chief 600 (the earlier generation) supports the same export through the Kongsberg KME service tool. Whatever the platform, the rule is: dump first, swap second.
Identify the card that has actually failed
Bridge or ECR alarm pages will tell you the cabinet, the rack and slot, and usually the module type — but not always the failure mode. Open the cabinet, look at the controller LEDs at the front edge. A solid red 'CPU FAULT' is unambiguous; a flashing amber 'BUS ERROR' is often a backplane issue or a downstream input/output card pulling the bus low. A 'COMMS LOSS' on a remote I/O drop usually points to the field cabinet, not the central controller.
Before swapping any card, measure the 24 VDC backplane voltage at the test points printed on the inside of the cabinet door — Kongsberg standard is 22-26 V loaded. A drooping backplane voltage that recovers when you unplug one card pinpoints the failed module without trial-and-error replacements. Carry a clamp-on DC ammeter (Fluke 376 or equivalent) — current draw on the backplane is the second clue.
The physical swap — sequence and ESD discipline
K-Chief controllers are hot-swappable on the redundancy-protected racks but not on the single-controller pages. Read the cabinet wiring diagram before pulling any card. If the system has dual redundant controllers, fail over to the standby through the service tool before extracting the active. If not, schedule the swap during a planned standstill — at anchor, with the engine room manned and the chief informed.
ESD discipline is non-negotiable. Marine ECR cabinets accumulate a surprising amount of static, especially in dry air-con environments at sea. Wear the wrist strap clipped to the cabinet ground stud, not to the rack. Place the new card on a static-dissipative mat (we carry a folded one) before removing it from the antistatic bag. Insert with steady firm pressure until the backplane connector seats — Kongsberg cards seat with an audible click; if there is no click, you are not fully home and the bus will not initialise.
Restore the configuration and verify on-line
After the new card is seated, power-cycle the controller (or let it auto-boot if hot-swap was clean). The Configuration Tool then writes the saved .cfg back to the controller. Verify the firmware revision on the new card matches the project — Kongsberg pushed a K-Chief 700 firmware update in 2019 that changed the way alarm priorities are stored; mixing pre-2019 and post-2019 cards inside the same cabinet causes intermittent priority-swap faults that take days to diagnose.
Once configured, walk every alarm point under the chief engineer's watch. Trigger a test alarm at three different I/O modules (one binary input, one analogue input, one binary output) and confirm the ECR alarm page receives it in the correct priority and within the standard 2-second poll cycle. The chief engineer signs the test sheet; we leave a copy in the cabinet and one in the project file.
Where the replacement card comes from
Genuine Kongsberg cards are sourced through Kongsberg Maritime service centres — Houston, Seattle, Rotterdam are the closest hubs for US-port deliveries. Lead time is normally 24-72 hours for the high-runner modules (CPUs, common AI/AO modules) and 5-10 days for the lower-volume specialised cards. We stage frequent failure-mode spares (e.g. CP4-series CPUs) in our US distribution position to cut a day off the lead time when the vessel is already alongside.
Equivalent modules from third-party suppliers exist for some I/O cards but not the CPUs. Class society acceptance varies — DNV and ABS will usually accept a documented equivalent for non-safety-critical I/O; safety-critical fire and gas detection points require the OEM card. We default to OEM and only propose an equivalent when the lead time forces the question, and only with written customer acceptance.
Praxis Selma and other automation platforms
The same principles apply to Praxis Selma (common on Turkish-flag bulkers and some Greek tankers), ABB AC-700 (industrial-marine crossover platforms on offshore support and FPSOs), and Lyngsø Marine (older but still installed on container ships from early 2000s). Configuration export, card-level fault isolation, ESD-disciplined swap, on-line verification — the workflow is invariant.
What changes is the service tool, the backplane voltage spec and the firmware revision protocol. We carry tools for K-Chief 600/700, Praxis Selma, ABB AC-700 and Lyngsø on every automation dispatch. For platforms we do not normally cover (Yokogawa CENTUM marine variants, Honeywell), we coordinate with the maker for a parallel attendance — typically arriving at the next port with their service engineer.
FAQ
- Can we attend remotely if the cabinet has a service VPN?
- For diagnostic and configuration export, yes — Kongsberg's remote service link lets us read the controller without boarding. The physical card swap still needs an ETO at the cabinet.
- What about K-Chief 600 in older bulkers — is it still supported?
- Yes. Spares are harder but available through Kongsberg service centres. We hold the K-Chief 600 service tool and the original maker software image for systems we cover regularly.
- How long does a typical PLC card attendance run?
- Four to eight hours alongside, depending on configuration restore time and whether dual-redundancy fail-over is available. Single-controller cabinets in single-line propulsion vessels need a planned standstill — usually scheduled during cargo work or at anchor.
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