Climma CWS MODUL chiller alarm codes: what we recorded
Root cause not determined; independent investigation sought. This page explains, in plain English, the alarm families shown by the Danfoss MCX controller on a three-module Climma/Veco CWS MODUL 3603 chilled-water plant, and lists every alarm recorded on this yacht. Meanings follow the manufacturer’s alarm-code sheet (C859-05) and the published CWS MODUL manual section headings. It is not a service manual; always follow the manufacturer’s instructions.
| Codes | Family | What it generally means | Recorded here |
|---|---|---|---|
| 22, 23, 24 | CAN-BUS MOD 1/2/3 KO | The master controller has lost data contact with module 1, 2 or 3 over the CAN bus. Causes can include cabling, connectors, termination or a module that has stopped responding. | Yes: modules 1, 2 and 3, 2024 and 2026 |
| 7, 45, 52, 55 | Flow alarms | Too little water flow detected (chilled-water or seawater side). Causes can include a blocked strainer, air, a pump fault or a faulty flow sensor. | Yes: unit 2, 2024 and Jul 2026 |
| 30 | DRIVE ALARM | A generic alarm from the inverter drive that powers the compressor. The specific cause (for example overheating, over-current or under-voltage) is a sub-code, shown when the alarm line is highlighted on the controller and Enter is pressed. | Yes: units 1, 2 and 3; sub-codes partly recorded |
| 16, 53 | Antifreeze | Chilled-water temperature too low. | Not recorded |
| 50 | Low pressure (LP) | Refrigerant low-pressure switch tripped; manual reset. | Not recorded |
| 1, 2, 46–48 | Probe faults | A temperature sensor reads out of range or is disconnected. | Not recorded |
How to read a Code 30 drive alarm
- Photograph the alarm list before resetting anything.
- Highlight the Code 30 line on the controller and press Enter to see the drive’s own sub-code.
- Photograph that screen too, and note the date and time shown and whether the yacht was on shore power or generators.
- Check the controller clock against real time, so the event log can be lined up with other records.
Every alarm recorded on this yacht
Dates are indicative because the controller clock setting has not been verified, and Code 30 sub-code decodes have not been confirmed by the manufacturer.
| # | Date | Unit | Code | Screen text | Meaning (C859-05) | In plain English |
|---|---|---|---|---|---|---|
| 1 | 02-01-24 07:51 | 3 | 30 | DRIVE ALARM | Inverter alarm, sub-code 3: inverter overheating | The drive for compressor 3 got too hot and shut down |
| 2 | 02-01-24 08:18 | 3 | 30 | DRIVE ALARM | Inverter overheating | Same again, 27 minutes later |
| 3 | 02-01-24 09:01 | 2 | 30 | DRIVE ALARM | Inverter overheating | The drive for compressor 2 got too hot |
| 4 | 02-01-24 10:14 | 1 | 30 | DRIVE ALARM | Inverter overheating | The drive for compressor 1 got too hot: all three drives overheated within about 2.5 hours |
| 5 | 03-03-24 | 2 | 7→52 | Low fresh water flow / repeated flow alarm | Low FW flow, then 4th repeated flow alarm | Water stopped flowing properly through module 2, repeatedly |
| 6 | Aug-24 | plant | — | Whole-plant shutdown | Reported as CAN communication fault; code not recorded | The whole plant stopped; reported as the controller losing contact with the modules |
| 7 | 13-12-25 | 1, 2 | — | DIS-VOLT state, ~30 s after start, no alarm logged | Not a code; matches Code 30 sub-code 10 “temporary undervoltage ×3 – DISUV” | Drives saw a brief low-voltage dip three times just after start; no alarm was saved |
| 8 | May-26 | plant | — | Shutdowns incl. display, no alarm logged | No code | The plant, including its display, switched off with no alarm saved |
| 9 | 27-07-26 00:49 | 1 | 22 | CAN-BUS MOD 1 KO | Missing CAN communication, module 1 | The controller lost contact with module 1 |
| 10 | 27-07-26 02:24 | 2 | 52 | FLOW METER ALARM | Repeated FW flow alarm (4th) | Module 2 water-flow alarm, fourth repeat |
| 11 | 27-07-26 02:34 | 2 | 52 | FLOW METER ALARM | Repeated FW flow alarm | Module 2 water-flow alarm again |
| 12 | 29-07-26 11:34 | 2 | 7 | FLOW METER ALARM (autoreset) | Low FW flow; flow 6.71→0.00 m³/h, plate 62.3 °C | Module 2 water flow dropped to zero and its drive plate reached 62.3 °C |
| 13 | 11-08-26 17:08 | 2 | 23 | CAN-BUS MOD 2 KO | Missing CAN communication, module 2 | The controller lost contact with module 2 |
| 14 | 11-08-26 20:33 | 2 | 23 | CAN-BUS MOD 2 KO | Missing CAN, module 2 | Lost contact with module 2 again |
| 15 | 11-08-26 20:34 | 2 | 30 | DRIVE ALARM | Inverter alarm, sub-code 1: inverter over-current | The module 2 drive saw too much current |
| 16 | 11-08-26 20:57 | 2 | 30 | DRIVE ALARM | Inverter over-current | Too much current again on module 2 |
| 17 | 19-08-26 12:54 | 2 | 23 | CAN-BUS MOD 2 KO | Missing CAN, module 2 | Lost contact with module 2 |
| 18 | 19-08-26 | 2 | 23→30 | — | Missing CAN mod 2, then inverter over-current; ~5.6 Ω phase to earth measured | Lost contact, then too much current; compressor 2 then measured as shorted to earth (about 5.6 Ω) |
| 19 | undated | 3 / 2 / 1 | 24 / 23 / 22 | Active alarm list | Missing CAN, modules 3, 2 and 1 – all three off the bus | None of the three modules was talking to the controller |
| 20 | undated | master | — | MASTER ALARM, water 30.7 °C, FWP OFF, COMP 0/3, WATER FLOW SHUT DOWN | Plant shut down on FW flow, no compressors | The whole plant stopped because water was not flowing; no compressors running |
Have you seen the same sequence (CAN dropouts, flow alarms and Code 30 drive alarms) on a Climma CWS plant? Please tell us. See also the technical facts and the timeline.