A night watch, monster blue fin, the end of Mr. Shabby, and further experiments with the high power DC charging system. Mark Fritzer writes:
I absolutely love being on the water at night. It is my favorite time to be aboard. Looking up at the millions of stars slowly rolling from side to side as the boat sways, brings perspective in a way nothing else can. Usually, the new guy gets the 12-4 shift, but Pete and Steve have a routine and asked me to take the cake shift – 8-12 – so here I sit at 2300 watching the stars. Our current position is 11°45.34′ N by 160°06.6′ W with the seas still on our nose out of the N at 1-2m. The wind has backed a little to the ENE at 15. The skies are mostly clear with the occasional squall barreling by on the radar.
We had an interesting but minor issue last night with the navigation lights, that brought to light another construction detail used in the FPBs. I thought it interesting enough to comment on, having spent a fair bit of my life tracing down bad wire connections buried in head/hull liners. Because of the propensity for light bulbs on boats to fail from power fluctuations, we have a DC-DC power conditioner feeding a constant 24.6 VDC to the nav lights. In addition, we have a direct power feed as a backup source of power, should the line conditioner ever fail. When we turned the power on, the port/stbd running lights didn’t illuminate, but the stern light did. After a quick search through the as-built electrical drawings, and knowing where the main power connection point is located in the forward basement, I went down to investigate. Neatly labeled and in one place, I found all of the connections for the nav lights located on the aft end of the stbd side, forward basement wire terminal strip. Here’s the cool part; every single light has a dedicated wire home run to this termination point. Nothing was daisy chained in the headliner. No buried connections inside the mast where the two running lights were linked. Everything located in one central place without interruption from source to load. In addition, not only is the positive side switched at the circuit breaker panel, but the negative side as well. No more chasing down a ground on the engine block when the circuit runs forward. Of course, I didn’t find a problem, cycled the breaker and the lights came on, but checked the terminal tension while I was there as SOP. Probably comes down to the number one failure on a boat – user error.
Victron suggested we adjust the Power Assist factor from 2 to 1.5 or even 1 to see if we could fine-tune the system to play nicer with the generator. Using the VE config software, I adjusted the Power Assist factor from the factory preset of 2 down to 1.5 and found the system didn’t kick in as quickly to pick up the load when the generator started to lag. My gut instinct was that it was waiting too long so I adjusted it back to 1.7 then 1.8 and the system started picking up the load from generator at the proper time, yet not immediately. It seems to let the generator carry the load just a bit longer and appears to have quit jumping in immediately and cycling more often. What I wouldn’t give to have my Fluke scope-meter 125 back, but that’s another story.
In addition, I ran the batteries down to about 75% and adjusted the charger output of the Victron units back up to full output of 70 amps each (210 total @ 28.2 VDC). I put a fan down in the basement to move some air around the units, to see if it would keep them from indicating an overheat situation. I measured amperage outputs at both the combined 24VDC positive battery cable as well as each independent output with a Fluke 374 clamp-meter, and I made the temperature measurements with my new favorite tool, the Flir i7 thermal imaging camera. I started with an ambient room temp of 91°F, ambient basement temp of 97°F and inverter/charger case temps measured on the middle front of 118°F. The results were significant in that the chargers started putting out 180-190 amps and ran that way for over 20 minutes without a temperature alert. During that time the ambient basement temp went up to 100°F and the case temps climbed to 128-130°F. After about 20 minutes I turned the fan off and the panel indicated a temp alert in less than 5 minutes, at which the case temps climbed to 158°-160°F. I had to turn the fan on high and open the basement door until the units came down under 145°F to get the alert to go away. I ran them this way until the batteries came up to 85% SOC at which point, the chargers started to taper off their output. We think we have a solution here, so we’ll continue to monitor. In the meantime, Pete had me set the charger outputs back down to 165 amps (60, 53, 52 amps respectively) until we are certain.
Mr. Shabby went out in style today. Last we saw of him, he was being flung out of the mouth of what appeared to be a monster Blue Fin headed in the opposite direction. Until now, I’ve never experienced a reel burn, but am now the proud bearer of not one, but two burnt thumbs. This fish hit like a freight train and took line for a solid 45 seconds. The first bit of that I was trying to get the drag set to max, which didn’t even begin to slow him down. After about a minute, I was able to thumb the spool down to a stop (burn #1) at which point the monster started jumping back and forth across the wake. Straight up out of the water 6 or 8 times from vertical, to horizontal leaps with Jordanesque hang time. Even from 300 yards away, you could see it was massive. I was able to slow him on the second run (burn #2) but at that point, the line snapped, he jumped and you could see Mr. Shabby turn end over end as the tuna leapt skyward in joy headed about 25 knots in the opposite direction. Seeing Mr. Shabby rotting in the bottom of a tackle box just doesn’t seem a fitting end to such a fine friend, and we are all happy he received a proper send off.