Sunday, February 10, 2013

Winter electrickery

There's a fair old blizzard blowing outside the boat. Despite us being hunkered down safely between Owl and Henry Cleaver either side of us, we are getting quite a buffeting. The wind is howling a bit. The afternoon Rick and Marilyn came over in the rain for lunch and by the time they left all outside was white. Here aboard Herbie I have spent a fair part of the last couple of days doing electrical jobs.

The main job was to put together and install the new ammeter and shunt to measure the output of the solar panel. Until now we have never been sure of whether it is performing to spec. Subjectively we know that it helps us to get through a day moored up without running the engine, although recently I had been suspicious that it wasn't doing as much as I would hope. Little did I know I was about to find out why.

I installed the shunt in the return earth wire between the batteries and the solar controller. As it was dark when I did it I had to wait until daylight this morning for the solar panel to put out some power to measure. Somewhat excited (I know I'm sad), I pressed the button and the meter read . . . . Zero! Oh dear. I double checked the wiring. All ok. Then I noticed on the controller box, instructions about in what order the wires should be attached. Apparently it makes a difference. the instructions say to flow them "in strict order". So I covered up the solar panel to stop it generating, undid all the wires and replaced them in the correct order. Oh dear again. Still no result. Perhaps I have bust the controller. Grrrrrrr.

Desperation now. Out with the voltmeter and I start measuring here and there. Hmmmm, the wires from the panel to the controller show about 20 volts. As it should. The wires to and from the battery read near zero. That can't be, can it. They just measure the battery voltage and I know that is about 13 v at the moment. So outside I go into the engine bay to look at the wiring at the battery end. There is the answer, but gawd knows how it came about. The positive wire from the controller to the battery was not attached. All I can guess is that the guys at Calcutt removed it when they were working on the engine or on the alternator. That would explain what the solar panel seemed not to be doing much lately. It was't doing anything!

Well it's all working now. This afternoon in the gloom and the rain, the panel, lying flat on the roof was putting out about half an amp. Not a great deal, but acceptable in the conditions and quite enough to keep the batteries up while we leave the boat here over winter. If the sun ever really shines again we're right back in business.

More else trickery tomorrow, I'm replacing our old built in radio with a new one which has a socket for us to play music from our iPads. About thirteen different wires to connect in a cramped space. Deep joy.

3 comments:

Val Poore said...

Nice to know that Herbie is still keeping you busy Neil, but now, iPads? Golly! that's very 21st century indeed :-)

Halfie said...

Isn't it satisfying, though, discovering an obvious fault like that, rectifying it, and seeing that it all works again? So much better than an intermittent fault.

Halfie said...

Isn't it satisfying, though, finding an obvious fault like that, rectifying it, and seeing that all works again? So much better than an intermittent fault.