[Public-List] Bizzare electrical problem

Glennb brooks.glenn at comcast.net
Fri Apr 5 17:51:27 PDT 2013


Hello all,

Well today as I was prepping the boat for spring I happened to reach deep into the aft storage space aft end of the cabin,over the ice box, and noticed my aux VHF antenna cable was extremely hot, bubbling the plastic core in one one spot.  This occurred where five small coils of excess cable were tied off with a plastic electrical tie.  The run of cable from the five coils up to the vhf was hot as well, as was the back end of the radio where the ant cable plugs into the unit.  The cable connects to a new last year  shakesphere emergency/backup antenna clamped to the aft taff rail.  The cable runs aft through the storage space, through the stbd locker thence into the lazarette where it connects up through the deck into the antenna.  The cable  is not connected to anything else on board- and is not shorting to any other hot electrical wire.  There are a half dozen positive leads running forward, that cross the cable near where the five coils were hot, but they are two strand are coated marine wire and were undamaged, not energized, and cold to the touch.

The radio was turned off.  The circuit beakers were turned off. Nothing onboard was energized except the bilge pump circuit, and the engine starting circuit.  I had just changed the engine oil and ran the motor for about 30 seconds to oil the engine and check oil level, prior to finding the heated cable.

After discovering the heated cabling, I shut everything off and systematically turned on the engine, circuit breakers  and radio, but was not able to duplicate the condition.

What in the world could cause a near fire temp in a VHF antenna cable under these conditions??? !!!

Any ideas greatly appreciated!

Glenn
Dolce 318

Sent from my iPad



More information about the Public-List mailing list