Yanmar's genset range

Built by Italian marine genset specialist, Mase, utilising proven Yanmar industrial engines, Yanmar's gensets range from 2.0 to 7.8kW. All units are compact for their outputs and have low oil pressure and high exhaust gas/alternator temperature shutdowns.

SEAWATER/AIR INTERCOOLED MODEL
Known as the IS 2500, this produces 2.0kW maximum and 1.7 rated (continuous) in the 240V/50 Hertz version, with a power factor of one. The voltage stability is plus or minus 10% and frequency stability plus or minus 5%. The unit also provides 10 amps of battery charging capacity.

A single cylinder 211cc direct injection aircooled diesel running at a constant 3000 revs with centrifugal-mechanical governing provides the power, yet by encasing the engine and alternator in a plastic shroud, the noise level is only 54dBa at 7m. The engine develops 4.2hp, so is understressed in this application.

To provide adequate engine and alternator cooling without the need for bulky aircooling intake and exhaust casings, Mase has cleverly used a system of seawater to air cooling. The hot engine air is cooled by seawater circulating through a heat exchanger, reducing engine and alternator temperatures to acceptable limits without the need for a watercooled powerhead.

And while the aircooled powerhead will always use more oil than a watercooled unit, due to the greater piston ring to cylinder clearances, it eliminates the possibility of coolant leakage into the cylinder should the head gasket fail.

Mainly because of the aluminium-head diesel and the plastic shroud, the IS 2500 has a dry weight of only 65kg. The unit measures 510mm long, 403mm wide and 465mm high.

Apart from the engine protection equipment, a digital hourmeter and a shielded 10m wiring cable are standard. The alternator is a synchronous two-pole unit and the rotor and stator are resin-coated to reduce corrosion, while the rotor is dynamically balanced for a long service life.

The seawater inlet connection requires a pipe with a 15mm diameter, the fuel inlet line is 8mm and the exhaust outlet 45mm. The minimum starter battery requirement is 45 ampere hours.

Four vibration-isolating mounting feet are provided and the genset will operate at up to 30? of heel, making it suitable for yachts and motorsailers.

To simplify onboard maintenance, access to the fuel injection equipment, engine oil dipstick and oil filter, seawater pump and air cleaner element are on one side. An oil sump pump is provided to eliminate having to drain oil from beneath the unit. However, as the oil sump capacity is only 0.8lt, the oil change interval should be no more than every six months or 50 running hours - whichever comes first - especially as the greater gas blow-by of aircooled engines dilutes the oil far faster than watercooled units.

The warranty provides two years of coverage.

Power Equipment, the Australian distributor for Mase gensets, told me in July it was working with a local company to develop an inverter genset, similar to what Honda has done with its brilliant EU series of portable units. The inverter concept is best suited to relatively high-revving engines (for example, the IS 2500 engine revs to 3600 when producing a frequency of 60 Hertz). This would enable gensets such as the IS 2500 to produce commercial-quality electricity for powering computers, etc.

SEAWATER/FRESHWATER INTERCOOLED MODELS
Yanmar offers two gensets that utilise watercooled diesels with cast-iron heads and conventional heat exchanger cooling. Both produce their rated power at a constant 1500 revs with centrifugal-mechanical governing eliminating the need for the EU concept and dramatically increasing engine lifespan.

Both units have an hourmeter and overload circuit breaker, but because of the lower revs use a synchronous four-pole alternator with dynamic balancing and the same level of corrosion protection as the IS 2500.

Known as the IS 65, the smaller unit produces 6.5kW maximum and 5.7 rated at 240V/50 Hertz with a power factor of one. The battery charging circuit is 40 amps and voltage stability plus or minus 10% and frequency stability plus or minus 5%.

The powerhead utilises a three cylinder 1006cc indirect injection unit that can develop 11.5hp and again is understressed in this application.

The IS 65 measures 760mm long, 530mm wide and 625mm high complete with its aluminium framed and sheeted case, and weighs 230kg. The sound level at 7m is a low 49dBa.

The seawater inlet pipe diameter is 16mm, fuel inlet 14mm and exhaust outlet 50mm. A minimum 70 ampere hour battery is required for starting the unit.

The IS 8 model produces 7.8kW maximum and 7.2 rated at 240V/50 Hertz with a power factor of one. The battery charging capacity is 40 amps and voltage stability is an excellent plus or minus 2%, while frequency stability is plus or minus 5%.

The IS 8 is powered by a three cylinder 1204cc indirect injection engine that can develop 13.5hp.

The IS 8 is 837mm long, 568mm wide and 688mm high and complete with aluminium casing weighs 295kg. The sound level at 7m is 49dBa.

The seawater inlet pipe and exhaust outlet diameters are the same as the IS 6.5, but surprisingly only an 8mm fuel inlet pipe is required. The minimum battery capacity is 70 ampere hours.

Controls for both models are incorporated in one panel. By removing a side panel, the engine oil dipstick and canister-type oil filter are easily reached. An oil sump pump is provided to eliminate crawling under the units to change oil.

The relatively small 2.3lt oil sump capacity of the IS 6.5 means that oil change intervals should be no longer than every six months or 100 hours, whereas the massive 5.2lt sump of the IS 8 can absorb more sludging and withstand longer intervals.

Both units use a double vibration damping system to reduce their intrusiveness when running, although the three cylinders reduce vibration to a minimum anyway. And because they can operate at up to 30? of heel, they are well suited to installation in motorsailers.

The warranty provides two years of coverage for both units.

For more facts on the IS 2500, IS 6.5 and IS 8 contact Michael Blair at Power Equipment, tel (03) 9757 9210 or email:michael.blair@yanmar.com.au.