Download Built-in generators

practical: power
Running an air-conditioner in the tropics
is one reason to have a generator.
Built-in
generators
THINKSTOCK PIC
Andrew Norton follows up last month’s article about
portable generators with a look at built-in generators.
If you’re going to invest in a built-in
genset, then I recommend only diesel
and never a petrol unit. At the risk of
offending manufacturers of petrol units,
having seen how quickly a fibreglass
boat burned to the waterline when its
leaking petrol fuel system ignited (and
felt the immense heat standing even
10m upwind) I would never ever have a
petrol genset in the bilge of a yacht.
Portable petrol gensets are fine
because they’re normally stored in
a cockpit locker and only used on
the deck, out in the open where any
fumes from the fuel tank breather
instantly vent to the atmosphere. But
although petrol is lighter than air and
quickly rises, any stray spark from
the alternator brushes or windings
can easily ignite vapours from the
carburettor. Besides, if your yacht’s
auxiliary engine is a diesel, why would
you have the complications of a separate
fuel tank when the genset could feed
from the main tankage?
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However, to avoid the potential for
cross-contamination most genset
manufacturers recommend installing
a dedicated fuel tank.
Why a built-in genset?
The main reasons why anyone would
choose a built-in genset is to power
appliances that can’t be supplied by the
auxiliary engine’s alternator, such as a
full-sized microwave oven or aircon for
tropical cruising.
Not having gas or alcohol onboard
to fuel a stove is a real step towards a
non-explosive cabin atmosphere. My
first yacht had an propane gas stove
and while I never had leakage problems
it always gave me the creeps when
lighting it. At 120 RON or Research
Octane Number (premium unleaded car
fuel is only up to 98 RON), propane or
LPG is incredibly explosive and being
heavier than air finds its way into every
crevice in a bilge. Alcohol is less volatile
but has a much lower calorific value per
litre, resulting in sometimes painfully
slow cooking.
In my opinion if you like cooking with
gas then buy a butane-canister-powered
single-burner stove from your local
camping store and use it only on deck.
At 98 RON butane is far less volatile
than propane.
As I mentioned in part one, having
an auxiliary engine-driven alternator
capable of supplying electrical loads
such as a galley hotplate via an inverter
still will not place enough load on even
a 40hp diesel, resulting in cylinder
bore glazing down the track through
excessive injector fuel spray relative to
engine load.
The answer is a built-in diesel genset
and the smallest units start at around
1.7 kW (Kilowatts) or 2.0 kVA (1000
x volts/amps) of rated or continuous
output, whereas the most powerful
portable inverter petrol genset
weighing less than 30kg is Yamaha’s 2.5
kVA EF2800i described in part one.
practical: power
Fischer Panda’s 4000s, 5000i and 8000i.
Of course, just like installing an
auxiliary engine a built-in genset
requires the same attention to detail,
such as routing fuel lines and the
exhaust pipe (again a waterlock system
is normally needed because the genset
is mounted below the static waterline)
and connecting battery wiring. At least
you don’t have to worry about correct
propshaft alignment.
Fixed rpm or inverter?
As with the portable gensets discussed
in part one, onboard gensets are either
fixed rpm or inverter with engines
in the latter type revving only as fast
as needed to power the appliances
connected. All the gensets in this
review are single phase and designed
to power normal household appliances,
whereas three-phase power is needed
to power welding units and if you have
a steel yacht that requires repairs
a portable three-phase genset in
addition to the built-in unit would be
the way to go.
Compact fixed rpm AC gensets have
been around since the sixties when
transistorisation reduced alternator
control components to an acceptable
size. Fixed rpm gensets rev at either
3000 or 3600 rpm to produce 230-240
volts and 50 Hertz (cycles per second) or
110 volts and 60 Hz for the US market.
They are relatively simple to maintain
and service although because the
alternator is separate to the engine
they’re fairly bulky for their output.
The main drawback with fixed-rpm
gensets is that during continuous usage
the engine must have no less than
50 percent of rated load (maximum
continuous output) on it to prevent
glazing the cylinder bores. While in
“Not having gas or alcohol
onboard to fuel a stove
is a real step towards
a non-explosive cabin
atmosphere”
a small genset this is easy to achieve
by leaving a galley hotplate on, when
operating power tools or even a
microwave oven there will insufficient
engine load. So a “dummy” load must
be connected to maintain at least 50
percent of the rated load.
Because the engine is spinning at
a fixed 3000 or 3600 rpm regardless
of load it is fairly noisy, although the
soundproofing enclosures fitted to
most built-in gensets do reduce engine
noise to tolerable levels. But no-matter
how good the enclosure is at containing
mechanical noise there’s still the noise
of the exhaust where it exits
the topsides.
Fixed-rpm gensets
In the past fixed-rpm gensets have had
fairly dodgy electricity output quality,
with poor voltage and frequency
regulation and sine wave forms
more akin to jagged mountain peaks
than the relatively smooth curves
of mains AC power. However, with
automatic voltage regulation and better
mating of engine torque and power
characteristics to the alternator the
voltage and frequency stabilisation can
be as good as inverter gensets. Some
of the gensets mentioned in this guide
have sufficiently good sinewave form
and voltage and frequency stabilisation
to run a laptop computer and switch
mode power supplies as used in
compact fluoro lights and multi-stage
battery chargers for topping up gel cell
or lithium ion batteries.
Inverter gensets differ from fixedrpm units in that the alternator is
incorporated in the engine flywheel
and produces three-phase AC power
instead of the traditional single-phase of
fixed-rpm units. The three-phase power
is converted to DC then back to singlephase AC, smoothing out the sine wave
form in the process to normally better
than mains electricity which from my
testing is rarely as good a quality as
power generation companies claim it is!
Because of this level of control the
engine needs to spin only as fast
as needed to supply the appliances
connected, significantly reducing
fuel consumption relative to load and
eliminating the need to have a “dummy”
load of at least 50 percent rated to
prevent damaging the engine. The
genset can also produce its full rated
output whether producing 230 volts
50Hz or 110 volts 60Hz, unlike fixedrpm units where the engine must spin
600 rpm faster to produce 60Hz.
Of course, being diesel with a lesser
rpm range than comparable-output
petrol engines a minimum load of
around 25 percent would still be needed
but less of a headache than maintaining
minimum 50-percent loading.
Noise levels
Noise levels between petrol-powered
fixed-rpm and inverter gensets are
significant and at seven metres, for
example, Yamaha’s EF2800i has a
decibel level of 60 compared to 65 for
its now discontinued fixed rpm EF2600
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practical: power
Nannidiesel’s DM350 and DM600.
quieter with Yamaha’s EF1000iS, for
example, emitting noise levels of 47dB
at seven metres. But then it won’t run a
galley hotplate or a microwave oven!
As with the petrol units the inverter
gensets are much lighter and a 3.5kW
or 4.1 kVA inverter genset may weigh 25
percent less than the same-output fixedrpm unit. That’s a big difference in the
bilge of a yacht!
For this article we have limited the
maximum genset output covered to
6kW or 7.1 kVA and only 3000 rpm units
because 1500-rpm gensets are way too
heavy for their output for a yacht.
Clean clothes at the push of a button . . .
every cruiser’s dream!
stablemate, a big difference considering
the EF2800i is capable of producing 0.5
kVA or 25 percent more while weighing
12kg or 29 percent less!
But because of the much higher
mechanical noise of diesel engines the
noise levels of three leading marine
genset brands are remarkably similar
and much lower than most portable
gensets. For example, the Homelite
720W mentioned in part one has a noise
level of 66dB at seven metres, rising
to 91dB at four metres and requiring
the wearing of industrial earmuffs to
prevent permanent hearing damage and
tinnitus. However, even a basic fixedrpm 3.5kW or 4.1 kVA diesel genset with
soundproofing enclosure has a noise
level of only 54dB at seven metres and
64dB at three metres. Only the small
portable petrol inverter gensets are
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Air or water cooled?
Compared to portable gensets, all of
which are air cooled, the built-in diesel
gensets have been designed using very
different technologies.
For example, fixed-rpm MASE
gensets marketed by Power Equipment
utilise air-cooled direct-injection
Yanmar diesels with an air/sea water
heat exchanger to maintain relatively
constant temperatures within the
soundproofing enclosure. Being air
cooled, the engine requires lower
maintenance than a water-cooled
unit because there are no cooling
passage zinc anodes to replace and
overall the gensets are lighter than the
competition. MASE gensets are made in
Italy using Italian alternators which are
some of the finest-quality units in the
world, a belief backed up by portable
genset manufacturers such as Gentech
and Toolex.
Fixed-rpm Nannidiesel gensets,
marketed by Collins Marine, have
direct sea-water cooling of the engine
and alternator to reduce noise levels
compared to air-cooled engines. For
tropical cruising engine temperatures
can be controlled more accurately
because water is a far superior cooling
medium to air but maintenance
is marginally higher. Although
Nannidiesel gensets are assembled in
France using either German Farymann
or Japanese Kubota diesels the
alternators are Italian.
Fixed-rpm Fischer Panda gensets,
marketed by Power Protection
Solutions, utilise direct sea water
or fresh water via a heat exchanger.
The latter does add some weight
to the genset but improves engine
performance through higher and
more efficient combustion chamber
temperatures and a narrower engine
cooling range. Lifespan is increased
because sea water is kept away from the
engine and alternator, but maintenance
is higher because there are two cooling
water impellers to service. For its small
fixed-rpm gensets Fischer Panda uses
Farymann diesels from a company that
from well back in the last century has
been making lifeboat engines.
Fischer Panda’s two inverter gensets
under 6kW are both powered by
freshwater-cooled diesels in keeping
with the upmarket image of these units.
Of the three leading brands covered in
this review these gensets have the best
voltage and frequency stabilisation for
sensitive electronic equipment. More on
this later. These gensets are powered by
Kubota engines.
Fixed-rpm air-cooled gensets
The smallest MASE model is the singlephase IS 2.6, which has a rated output of
1.7kW or 2.0 kVA and 230 volts at 3000
rpm from a single-cylinder 211cc diesel.
Complete with enclosure this unit has a
dry weight of only 80kg with length by
width by height dimensions of 500 x 380
x 465mm. The noise emission level is
54dB at seven metres although the level
at three or four metres and one metre is
not mentioned in the tech specs.
practical: power
Next up is the single-phase IS 3.5,
rated at 2.7kW or 3.1 kVA and 230
volts at 3000 rpm from a 296cc singlecylinder diesel and weighing 96kg. The
dimensions are 590 x 406 x 515mm and
noise level 54dB at seven metres.
Topping out the range is the singlephase IS 5.0, which is rated at 4.0kW
or 4.7 kVA and 230 volts at 3000
rpm, powered by a single-cylinder
406cc diesel and weighs 130kg with
dimensions of 675 x 468 x 565mm.
Again at seven metres the noise
level is 54dB.
However, one aspect of MASE gensets
is their voltage and frequency stability.
The voltage range can fluctuate from
207 to 253 volts and frequency from 47.5
to 52.5Hz, worse than some fixed-rpm
portable gensets and all of the portable
inverter units.
Electrical appliances in Australia are
designed to operate on 230 to 240 volts
and should the voltage drop below 216
switch mode power supply electronics
such as computers and even compact
fluoro lights won’t function. So while
MASE gensets might be suitable for
galley hotplates, microwave ovens and
battery charging using linear chargers
I’d be wary of connecting switchmode power supplies such as those in
computers and compact fluoros.
At least there’s a separate 12-volt 10amp battery charging circuit and at 30
degrees the maximum inclination angle is
useful for yachties because performance
won’t diminish in rough seas.
Fixed-rpm sea-water-cooled
Due to be released at the 2011 Sydney
International Boat Show, the singlephase Nannidiesel QF3.5 has a rated
and maximum output of 2.8kW or 3.5
kVA at 3000 rpm from its 290cc singlecylinder diesel. The dry weight is
105kg and enclosure dimensions 590 x
405 x 515mm. The noise levels are 52dB
at seven metres but interestingly not
much louder at 56dB at three metres.
Even at one metre the noise level of
60dB is quieter than many portable
fixed-rpm petrol gensets at seven
metres!
Next up is the single-phase QF6.0,
producing 4.4kW or 5.5 kVA rated and
230 volts at 3000 rpm from a twincylinder 479cc diesel. Having twin
cylinders makes a big difference to
vibration levels because twins don’t
suffer the cyclical reduction of rpm in
single-cylinder diesels between the
power and compression strokes. Yet
the weight is only 128kg with enclosure
dimensions of 650 x 480 x 530mm.
Both Nannidiesel gensets have
voltage output range of 219 to 241 volts
although frequency stabilisation is not
mentioned. Also the sinewave shape is
not mentioned but as the alternator is
an Italian Coeimo, combined with the
reasonable voltage stabilisation running
switch-mode power-supply appliances
should be acceptable. Both units
have maximum dynamic (underway)
operating angles of 15 degrees.
Fischer Panda’s single-phase 4000s
SC PMS produces 3.5kW or 4.1 kVA and
230 volts rated at 3000 rpm from a 298cc
single-cylinder diesel and weighs 93kg
respectively. The enclosure measures
575 x 365 x 550mm and at seven metres
the noise level is 54dB, rising to 64 at
three metres and 69dB at one metre.
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52dB-54dB Noise Level
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practical: power
The voltage output range is 219 to 241
volts and frequency 48 to 52Hz so the
chances are it should run switch-mode
appliances. A maximum inclination
angle is not mentioned in the tech specs.
Fixed-rpm fresh-water cooled
Fischer Panda’s single-phase 4000s FC
PMS is the only fixed-rpm genset to
have fresh or heat exchanger cooling
and this brings the dry weight to
97kg compared to its 4000s SC PMS
counterpart.
In all other respects the 4000s FC is
the same.
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What’s the difference between
kW and kVA?
Appliances such as fridges and aircon
units and power tools such as drills,
sanders and planers have PFs of around
0.8 with losses in the motor windings
so European manufacturers rate their
gensets in kW. Even though a tool may
have a running consumption of 500
watts it may actually consume more than
600 watts. This has to be allowed for
when combining electrical loads and the
European measurement includes this
and subsequently is more conservative.
Preferred in Asia and Australia
is kVA, which is simply 1000 volts
times amps with a Power Factor (PF)
of 1.0. For example, when powering
incandescent, halogen and compact
fluoro lights having a current draw of
one amp, this is 240 volts times one amp
equalling 240 watts or 0.24 kVA.
Examples of electrical loads
Regardless of the electrical load, when
using a standard 240-volt 10-amp
▲
Inverter freshwater-cooled
The only inverter units in this guide are
the single-phase Fischer Panda 4000i
PMS and 6000i PMS, both having heat
exchanger cooling of the engine and
alternator.
The 4000i has a rated output of 3.5kW
or 4.1 kVA at 2800 rpm from a 309cc
single-cylinder diesel and depending
on the electrical load the rpm can
drop to 2200, substantially reducing
engine wear and fuel consumption. The
dry weight is 79kg and the enclosure
measures 595 x 390 x 410mm. The noise
levels are 54dB at seven metres, 64 at
three metres and 68dB at one metre.
The 6000i has a rated output of
5.5kW or 6.5 kVA and is powered by
the same twin-cylinder Kubota diesel
as Nannidiesel’s QF6.0 but having
freshwater cooling and variable engine
rpm from 2200 to 2800. Its dry weight is
111kg and the enclosure measures 520 x
440 x 550, so it’s significantly taller due
to the upright engine. The noise levels at
seven, three and one metre are 52, 62 and
67dB so the 6000i is a very quiet unit.
Both units have voltage ranges of
223 to 236 and frequency ranges of 49
to 51Hz and combined with the sine
wave form claimed by Fischer Panda
can easily run laptop computers and
compact fluoros in addition to galley
hotplates and microwave ovens. Both
gensets can also run inverter aircon
units which are so much more energy
efficient than conventional units.
However, no mention of maximum
inclination angle is mentioned in the
tech specs.
Continued on pg75
▲
practical: power
Continued from pg56
household power cord the voltage output
drops by one volt for every two metres
of length. This may not seem like much
but with gensets having large voltage
ranges it can mean the difference
between powering and appliance and
not. So my advice is to have appliances
normally used mounted as close as
possible to the genset output sockets.
A single galley hotplate draws around
1500 watts on “high” and a cordless
kettle around 2200 watts (both with a PF
of 1.0) whereas a full-sized microwave
draws 1400 watts (PF 0.8), even though
it may be sold as a 650 to 780-watt
unit. This is because the magnetron
that produces the microwaves is still
relatively inefficient. And even though
a 500Lfridge may have a running
current of 260 watts (PF 0.8) when the
compressor starts it may draw up to 10
times that amount.
A non-inverter aircon unit also
has similar cold-start current draw
percentage but a soft-start inverter unit
can draw a lot less. However, portable
genset manufacturers suggest having
an alternator output of at least 3.2kW or
4 kVA for non inverter aircon units.
Cold starting and maintenance
Collins Marine thoughtfully supplied
an instruction manual for its gensets
so the info below is for operating and
maintaining Nannidiesel units but
Additional product info
NANNIDIESEL
Nannidiesel marine gensets are available
up to 526 kVA with 1500 rpm and threephase units starting at 7.2 kVA. The
engines are a mix of Kubota and Doosan.
For more information contact Peter
Collins, Collins Marine, Unit 26, 17-21,
Bowden St, Alexandria NSW 2015,
ph (02) 9319 5222.
FISCHER PANDA
Fischer Panda offers gensets in either DC
(for hybrid power systems) or AC output
and fixed-rpm or inverter units to 131 kVA,
powered by a mix of Kubota, Yanmar and
Deutz diesels. Unusually units to 78 kVA
run at 3000 rpm, which after all is what
the steam turbines in our coal-fired power
stations operate at!
equally applies to water-cooled
Kubota engines used in other
makes.
Nannidiesel recommends
priming the diesel fuel pump if
the engine has not been used for
several months, then checking
the fuel tank, engine coolant
tank (heat exchanger models)
and engine sump oil level and
opening the fuel feed valve and
sea water cock. The access panels
should be opened and the engine
and alternator vented for at
least five minutes. The battery
switch should be turned on and
emergency stop off.
Once the ignition key has been
turned to the on position an
audible alarm signal will sound
and after a few minutes only the
oil pressure, battery charge and
on indicators will remain lit.
Depress the Start button to the
midpoint to heat the glowplugs
for the indirect injection engine
(not applicable to direct injection
diesels) for five to 20 seconds
ABOVE: Where to put your generator is another issue.
then fully depress the start button
The owner of this French-built catamaran housed his
to crank the engine. On starting
Paguro generator in the port engine compartment.
the warning lights should go out.
I recommend warming a cold
engine for a least three minutes before
the engine then remember to turn off
applying load, starting with the least
the fuel feed and close the sea cock.
load first and progressively increasing
Nannidiesel recommends changing
loading. Disconnect electrical loads at
the engine oil and filter after the first 20
least two minutes before switching off
hours then every 200 or annually when
the engine thermostat and fuel pre-filter
should be replaced. If you’re using the
engine infrequently then I recommend
and contact details
changing the oil and filter every
For more information contact Andrew Wilson,
six months. An API-CD (American
Enerdrive Pty Ltd, Unit 11, 1029 Manly Road
Petroleum Institute) diesel oil having an
Tingalpa, Qld, 4173, Phone: 1300 851 535
SAE rating of 15W40 is recommended
Mob: 0400 141 290, Email:
for ambient temperatures from minus
[email protected]
15 to over 40 degrees.
Valve clearance adjustment is
MASE
recommended every 400 hours or every
MASE generators are also available in
two years when the freshwater coolant
1500 rpm gensets, starting with the IS 7,
should also be changed.
which produces 6.2 kW or 7.3 kVA and 230
volts rated from a three-cylinder 1116cc
Andrew Norton
Yanmar diesel.
Andrew has a marine engiFor more information contact Michael
neering background and has
Blair, National Marine Sales Manager,
contributed to Cruising Helms1 Waterway Drive, Coomera QLD 4209,
man since 1983. He primarph (07) 5580 4022, mob 0419 300 299,
ily evaluates marine engines and power
email michael.blair@powerequipment.
equipment as well as testing sailing boats
com.au
and recreational fishing boats and lives in
the Lake Macquarie NSW area.
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