Electric sea water pump - D2-55

[SVI]

Photos

[mcarling]

Interesting that 900W of solar panels are insufficient. Are they partially shaded most of the time? Perhaps the problem might be insufficient battery capacity? Upgrading from lead-acid batteries to LiFePO4 batteries might solve your problem. It would certainly reduce your problems, if implemented well.

[SVI]

Originally Posted by mcarling

Interesting that 900W of solar panels are insufficient. Are they partially shaded most of the time? Perhaps the problem might be insufficient battery capacity? Upgrading from lead-acid batteries to LiFePO4 batteries might solve your problem. It would certainly reduce your problems, if implemented well.

Done already 400ah CALB installed already last year, 400ah coming now.
Solar panels are on port side bimini, helping, but not sufficient.

We run 1 hour generator daily on anchor - to heat shower water in the evening. This year I double charger capacity (240A Victron), so only 30 min.

[mcarling]

Do you have a starboard side bimini onto which you could install another 900W of solar?

[SVI]

Originally Posted by mcarling

Do you have a starboard side bimini onto which you could install another 900W of solar?

No way, I have the helm and winches on starboard. Google Salina 48

[mcarling]

I googled the Salina 48 and looked at a lot of photos. In trying to determine where solar panels might be mounted, looking at photos is a poor substitute for experience sailing the boat. I cannot offer any specific suggestions but, if I were in your shoes, I would be looking for ways to add solar capacity -- even if it would sometimes be shaded. There are flexible solar cells that can be walked upon, so somewhere forward might be an option to consider.

[SVI]

Yeah, sure, will stick solar panels on the sails

Solar is good on land, but on a boat it is an expensive toy. Especially those plastic film-covered flex panels. Do you know the film gets foggy from salt, sand and UV after a year?
A good generator or alternator is a better investment.

[mcarling]

If you don't have confidence in solar, then by all means don't rely on solar. Everyone should choose a solution that they trust in. As for me, I always appreciate the people in the anchorage who find a way to make solar work.

[DougR]

Back with a little more info on the D2-55.......

You can pull a maximum of about 19 kW from the front of the engine, up to three separate pullies with 6.8 kW each. This spreads the load on the crankshaft as several belts pulling in different directions tends to balance the bending load on the crankshaft. Installing a single side load of the size which you envisioned will place a heavy bending load on the crankshaft and is best to be avoided. If you design a bearing supported shaft and drive the alternator from that, it would be much better.

The difference in the amount of power which can be taken from the front or the rear of the engine has to do with the design of the crankshaft. In the case of the D2-55 engine, the diameter of the rear of the crankshaft is about 80mm, while the front of the crankshaft at the large end of the taper is probably 25 mm. Plus, the power that is taken from the rear end is completely axiel in nature....no bending loads. The loads on the front of the crankshaft are almost completely side loads, and if you overload the crank with side loads, it can break, or wear out the front main bearing, or other things which are no fun.

As was mentioned earlier in the thread, circulation pump flow is low pressure and high flow. With a fully open thermostat and 35kPa external circuit back pressure, the D2-55 pump will flow as follows:
2400 RPM 65 l/min
2600 RPM. 70 l/ min
2800 RPM 75 l/min
3000 RPM 80 l/min

This means that the 12 volt pump shown earlier, with 12.5 l/min will be significantly undersized for the job at hand.

I think your idea of multiple smaller alternators with the standard circulation pump might be a better way to go.

DougR