Approximately 4 weeks after deploying a redesigned 5.5 km DDL Extension cable, the Node port that supplies power to the cable tripped on an over-current fault. Troubleshooting the issue is difficult as the only information that we have is the behaviour of the Node breaker when we try and power the cable. All indications suggest that we have a hard short circuit to sea water.
The worst case scenario would be an “event” that had physically damaged the DDL platform or the cable. To get a few more data points to assist in our maintenance decision making, we contracted Ocean Dynamics Canada Ltd. in Campbell River, BC to supply an inspection ROV and support vessel. The ROV was a SAAB SEAEYE FALCON
On Tuesday 20 Apr we proceeded out to the site of the DDL platform and launched the FALCON. The ROV pilot quickly located the platform and we were able to confirm that it did not appear to have been damaged or moved from its original location. We then commenced a cable survey to see if we could identify any visible damage to the extension cable itself. A storm was building and we were forced to recover the ROV before all of the cable had been inspected.
The dive confirmed that the DDL platform was intact and appeared undamaged. The extension cable in the vicinity of the node had moved and was now suspended off the bottom, resting on one of the Node lifting points. We could not confirm if the cable was showing any signs of damage where it was contacting the lifting point.
The next step will be unplugging the cable from the DDL Platform to see if there is an electrical fault in the Platform or connectors that is causing the issue. This will have to wait until we can get an ROV on-site with more capable manipulators.
