22 nautical miles
Today was a brilliant sail. Having put up the genoa with its new sacrificial edge we sailed out and really enjoyed ourselves.
But then Tim said the fateful words, 'We haven't had our incident today, what went wrong?' A few minutes later Jacob was in the cabin and he heard a clicking sound in the cabin. It appeared to be coming from the VHF transceiver while it was turned off! It couldn't be so I got Tim to try listening too... yes, it was coming from the turned off VHF transceiver.
Removing the antenna connector from the transceiver Tim got a severe shock. The VHF antenna which was arcing, every few seconds and that was the clicking sound we heard. The measured voltage across the antenna (while disconnected from the VHF transceiver) was in the order of 120 volts AC. The ONLY unit capable of this voltage was the Inverter, so I totally removed the 12 volt power from this and the arcing/voltage disappeared.
During this time the Inverter had been left in remote mode and the remote had it turned off.
Removing the antenna connector from the transceiver Tim got a severe shock. The VHF antenna which was arcing, every few seconds and that was the clicking sound we heard. The measured voltage across the antenna (while disconnected from the VHF transceiver) was in the order of 120 volts AC. The ONLY unit capable of this voltage was the Inverter, so I totally removed the 12 volt power from this and the arcing/voltage disappeared.
During this time the Inverter had been left in remote mode and the remote had it turned off.
When we got back to the marina I investigated further and could not reproduce the fault, but did find that with the 13 amp plug disconnected (ie nothing connected to the output of the inverter) there was a 136 volt AC potential difference between the earth on the output of the inverter and the negative (ie low voltage earth) on the 12 volts of the inverter.
This is obviously extremely dangerous and would explain why the RCD on the shore power would occasionally trip. It would also explain why the Automatic Switch failed, caused by a high earth potential where it would never expect such a voltage!
This is obviously extremely dangerous and would explain why the RCD on the shore power would occasionally trip. It would also explain why the Automatic Switch failed, caused by a high earth potential where it would never expect such a voltage!
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