Warning Voltage drops on FP
Orana probably Mahe, Liparis? & Salinas
Hi Guys,
This is an issue I had recently that may be of interest and applies to all? the
current FP models. I apologise for the
photo quality, I had to use a mobile phone/torch and the
Orana is now 10,000 miles away.
On the Orana the power is fed to 4 distribution boxes. On the Orana the first box is in the starboard
hull master
cabin, the next two are under the sofa (main cabin) and the last is in the port rear
cabin. All are wired in series, so a voltage drop in the first box is a voltage drop in the rest of the
boat. If FP joined the last box back to the
battery and made a ring it would be less of a problem! The box has a printed circuit board (PCB) with ten connections (push on/spade) to individual circuits each fused and connected to the main terminals by the PCB.
I was losing 0.75v from the
battery to my first box, so taking the box apart I found the main positive terminal was loose, so I took the connections off. Underneath there is a
single stainless? nut and 6 washers connecting the terminal to a PCB. Looking at the negative terminal there are two nuts. One to hold the bolt to the PCB and the other to lock it. So a nut is missing. Further examination of the postive terminal connection reveals that the connection to the terminal is via an uncoated tinned connection that the nut is tighten upto. So a loose nut creates a large voltage drop. So I checked the rest of the boxes, 1 was lose and 3 weren't tight.
So it may be a good idear to check all these connections. I presume these are stainless nuts and bolts, if so they have only 3% of the conductance of copper (Ref Calder). The maximum
current draw from any one circuit is 25 amp and most are much less. So its not a wonderful system of power distribution relying on the contact between 3 nuts and a PCB board.
Linear Mode
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