Equipment | Generator
This is a wonderfully compact unit from The Watermaker Store (USA) in San Diego, who sold us a discounted unit in partial sponsorship. It uses a marinised version of a 6 hp Kubota single cylinder diesel engine that is claimed to consume only0.5 litre/hour. At least, that's what the brochure says. After we unexpectedly ran out of fuel (our tanks have no guages, so everything is by dead reckoning) I tested the unit using a 1 litre bottle of diesel, and found it burns about 1 litre/hour when under load.
The folks at the The Watermaker Store (USA) marinise the Kibota themselves, and make a very good job of it, using high-quality materials. They add a 140 Amp Hour (but don't expect to get more than 120 amps at best, and usually 80-90 when the alternator has been running for a while and is hot) alternator and Voila! A 12V DC generator! Given that most folk use a 240 Volt (or 120) AC generator, costing over US$6k, to drive a battery charger, why not generate 12V directly? A battery charger wouldn't charge your batteries any faster than about 60 Amp anyway! For our mains' voltage requirements, we use a 1800 watt inverter, and make sure we have a big-enough 12 Volt battery bank (8 x 6-volt Trojans set up in pairs to give 620 AmpHours at 12 Volts) to cope.
So far we've run it for 300 hours without serious problem. The only things we are wrestling with are that it generates much more heat than our 150 cfm blower can clear from our under-cockpit compartment (so we have to remove the soundproofed side panels) and that it sometimes seems to generate an airlock and/or poor circulation in the cooling circuit resulting in intermittent overheating on start-up. The latter may be a result of my installation - I have a high anti-siphon loop on the discharge line for the seawater cooling circuit and the heat exchanger is placed rather high above the waterline. I've now lowered the height of the heat exchanger and, so far, this seems to improve the situation.
December update! I have now also lowered the anti-siphon loop and re-routed some hoses to allow trapped air to vent to the top of the reservoir and changed the seawater pump impeller - badly damaged (due to running dry?) - so maybe we have the overheating problem licked now!
January update! The generator ran great for 30 minutes... then trashed the toothed drive belt that powers the pump. The crankshaft sprocket was way out of alignment with the pump. Until I got a replacement belt, I rigged a temporary electric pump for seawater cooling; a very dangerous solution since if this is left on when the generator is shut down... the exhaust will fill and flood the cylinder! When I got a new belt I found the crankshaft-driven pulley had migrated down the shaft (don't know why) causing the misaligment and trashing the belt. I re-aligmned and fitted the new belt. So far, so good!
Be aware that the installation does require a lot of small ancillary pieces of equipment, other than the bare engine shown here. If you are tight on space, this is great because you can mount these parts pretty much anywhere you have space. It can result in something of a forest of hoses and wires, though.
You can also get versions with a Junior Bauer dive compressor and/or a high pressure pump for a watermaker. If you are in the market for a generator, dive compressor and/or watermaker, check out their products for value and to keep within tight space limitations. You can email Dory Thompson at firstname.lastname@example.org ; she's very helpful.
© JIOQ 2004, 2005