T&T: Genset bog down under load
capefe...@aol.com
Edmond Badham
COSMO
Wilmington, NC
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lrze...@aol.com
Bob writes that the Marineland Marina is now open. Actually it
has reopened after being closed for about 10 years. Below is an excerpt
from out 1995-96 log.
"We bought our Willard Horizon, Puffin, in Florida in 1995. It
was freezing up north and we intended to sail the boat in the balmy
waters of Florida for a few weeks before heading up the ICW to the
Hudson River. Puffin was docked at the Marineland, FL. marina. The
marina was just off a narrow and relatively uninhabited portion of the
Intracoastal Waterway between St. Augustine and Daytona. The Marineland
Oceanarium was the first place to stage live dolphin and whale shows.
Now over 50 years old, it looks small and unpretentious compared to the
bigger Sea World oceanariums in Miami and San Diego. The grounds were
well kept with flowers and palm trees. A small zoo with alligators,
snakes and tropical birds surrounded the show amphitheater. Marineland
exuded a certain run down charm which extended to the Marineland Motel
across the street and the marina itself.
Marineland is on a sandy barrier island nearly 20 miles long and a
quarter of a mile wide located between St. Augustine and Daytona. The
eastern side of the island fronts the Atlantic Ocean, the western side,
the Intracoastal Waterway. Other than Marineland and the motel, there
was little development along this stretch of the Florida coast. The
beach front was sandy and extended in both directions as far as the eye
could see. There were very few bathers. Just sea birds and acres of
shells.
At dusk all the marina regulars gathered on the veranda with a can of
beer, a glass of wine or a bottle of a stronger potable and swapped
boating lies until nightfall. One Canadian couple made the trip from
Montreal every winter and went back every spring. Eventually the
Canadian government told them they would have to spend more time in
Canada or lose their medical coverage. Now they leave their boat in
Florida, spend six months and one day in Canada, and like geese, fly
South every fall.
Another old timer had a slow growing form of cancer which was quickly
being overtaken by a speedy case of alcoholism. He was curious to see
which would kill him first. Most of the veranda crowd were betting on
the booze since he would start drinking late in the afternoon and not
stop until he had finished off an entire fifth of rum. At this point
his wife would gently lead him off to bed. Curiously, he never appeared
to have a hangover the next morning."
Marineland Marina is in a delightful location and it is well worth a
stop.
Larry Z
Peter Bennett
change the output frequency. (The engine sound will likely change with
increasing load, but not the RPM.)
On 10/15/2011 7:09 AM, capefe...@aol.com wrote:
> I have a old mechanical Onan generator that does not increase RPMs
> when put under increased load. Is this a governor problem?
>
> Edmond Badham COSMO Wilmington, NC
--
Peter Bennett, VE7CEI Vancouver, B.C., Canada
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vpsboat.com
Kim Boyce and Eric Thoman
A generator _should not_ change RPM with changes in load, as that would
change the output frequency. (The engine sound will likely change with
increasing load, but not the RPM.)
Peter Bennett
Reply:
In my observations, a generator will slow down under load. How cannot it
not? It is like driving your car up a hill. In fact, Northern Lights told
me long ago that when their generator is properly loaded it will slow down
to the point where it is producing electricity at 59 hertz. 58 is fully
loaded and 57 means you are about to stall. 61 plus is under loading. With
no load it is almost 62. We watch our hertz meter on our panel frequently
to see how the generator is loaded. If you do not have a hertz meter on
your panel you may want to get a multimeter with a hertz meter and run some
tests and get to know what is going on with your equipment.
I have always made the assumption that hertz relates directly to RPMs (on a
generator). If that is not the case it is big news to me....
Eric Thoman
Abyssinia
Peter Bennett
speed, but many will, as you say, reduce speed slightly with load. (and
yes, engine RPM is directly related to frequency in conventional
generators, but not on the "inverter" types like the Honda 2000.)
The OP's complaint was that his did not _increase_ speed with load,
which is probably an unlikely reaction. Perhaps, after reading our
posts, the OP can provide a better description of his problem.
Perhaps a better description is that the engine on a conventional
generator should not change RPM (up or down) by more than 5% or so from
no load to full load.
On 10/15/2011 3:44 PM, Kim Boyce and Eric Thoman wrote:
>
>
>
> A generator _should not_ change RPM with changes in load, as that would
> change the output frequency. (The engine sound will likely change with
> increasing load, but not the RPM.)
>
> Peter Bennett
>
> Reply:
>
> In my observations, a generator will slow down under load. How cannot it
> not? It is like driving your car up a hill. In fact, Northern Lights told
> me long ago that when their generator is properly loaded it will slow down
> to the point where it is producing electricity at 59 hertz. 58 is fully
> loaded and 57 means you are about to stall. 61 plus is under loading. With
> no load it is almost 62. We watch our hertz meter on our panel frequently
> to see how the generator is loaded. If you do not have a hertz meter on
> your panel you may want to get a multimeter with a hertz meter and run some
> tests and get to know what is going on with your equipment.
>
> I have always made the assumption that hertz relates directly to RPMs (on a
> generator). If that is not the case it is big news to me....
>
> Eric Thoman
> Abyssinia
--
Peter Bennett, VE7CEI Vancouver, B.C., Canada
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vpsboat.com
_______________________________________________
Dave Cooper
the hertz would be to low or too high. 3% of 60 cycles equals a low of 58
or a high of 62 hertz. Modern electronic throttle controls control this
function.
The genset manufacturer's job is to make sure that the engine chosen to turn
the alternator has enough torque to maintain the 1800 rpm when the genset is
fully loaded. If they have done their job then the electronic throttle
control can keep the rpms very close to the 1800 rpm required for 60 Hz
operation.
Now as the engine gains hours stuff happens. An injector may become out of
spec and one cylinder, even though firing, isn't able to produce quite the
power that it did when new. Now when you put the rated load on the genset
the engine will slow down slightly as that one cylinder is weak. As time
goes on another injector might join the 1st. Now when the electronic
throttle control asks for full throttle the engine isn't producing the
torque required to maintain the rpm. The Hz reduces even more. As this aging
process continues we finally get to a state where a full load will bring the
engine rpm way down and usually the genset output will trip, aka release the
load, if is too low.
The model/brand of the genset and the controls/monitoring that the
manufacturer put on it will govern what any given unit will do. The genset
market is competitive and often the engine is just barely sized such that it
can actually maintain a full load when new to make a price point. The better
brands always put an engine with a bit more torque and HP to give you some
margin for engine aging and greater surge loads.
Suffice to say that, unless the manufacturer skimped on the engine spec, if
you are seeing the Hz dropping or hear the engine slowing or bogging that
you have a problem with the engine not producing it's rated power.
Injectors, compression, applying a full load before it is warmed up, exhaust
restriction, etc. are all possibilities. Seldom have I found the throttle
control an issue unless someone has played with it.
Now if you are trying to pull more than the rated power from the genset then
you need to address the demand side of your electrical system and not the
genset ;-)
As always YMMV....
Dave & Nancy
Swan Song
Roughwater 58
Limin in Waikiki Beach
capefe...@aol.com
Edmond Badham
COSMO
WIlmington, NC
Steve Sipe
> A genset should not change speed under load--correct. But the problem
> is with this generator is that it does slow down. When an idling
> generator is put under increased load it needs to add fuel and air to
> generate the increase in power and keep the output constant. My
> question is what could be broken to for the normal increase in power
> not to occur?
>
controlled by the addition of fuel, not air. The mindset of a carbureted
gasoline engine where opening the throttle admits more air and thereby
increases the amount of fuel aspirated along with the air- doesn't
apply. It's backwards from carburetion. Adding more fuel provides more
energy to each combustion cycle thereby increasing the RPM, or in the
case of the genset, maintaining the RPM that injector pump is set up to
provide- as load is increased.
When you indicate "idling" I would presume you mean "unloaded"- as
previous posts outlined, the rpm shouldn't vary by more than a few
percentage points, so the engine always runs at the same rpm once it's
started.
Point being, a deficiency in the fuel side will be the most likely
culprit. A fouled injector, problems with the injector pump, a
restriction in the fuel supply, e.g. clogged filter, air leak, failing
lift pump, an adjustment in the linkage. The 1st place to look would
likely be the supply. Be sure that each filter and especially the final
fuel filter on the engine has been serviced. Perhaps further down the
line might come valve adjustment, depending on accumulated hours.
If you have a manual, check the troubleshooting tree. It will help you
stay focused and logical.
good luck!
--
Steve Sipe
Solo 4303 "Maerin"
Middle River, MD
Twin...@aol.com
In a message dated 10/16/2011 8:39:00 A.M. Eastern Daylight Time,
capefe...@aol.com writes:
A genset should not change speed under load--correct. But the problem is
with this generator is that it does slow down. When an idling generator is
put under increased load it needs to add fuel and air to generate the
increase in power and keep the output constant. My question is what could be
broken to for the normal increase in power not to occur?
Edmond Badham
COSMO
WIlmington, NC
A H FOSTER
Date: Sat, 15 Oct 2011 09:24:28 -0400
From: "Alan Wagner" <wagner....@verizon.net>
To: "Trawlers-and-Trawlering" <traw...@lists.trawlering.com>
Subject: T&T: Need Captain to Move Boat
Check your Email.
Capt. Bill
Dave Cooper
to check, filters, lift pumps, etc.
I also want to add that many newer diesel gensets are controlled by
electronic injector pump controls or electronic common rail injectors not
the older mechanical style. A mechanical one can't keep the engine in as
narrow a range as the electronic one nor react as fast to surges. Also they
have parts that wear so that as time passes their dynamic range increases so
the RPM variation increase. Soon all will be of this type in order to meet
the emissions rules. Mechanically controlled diesels are joining the age of
the dinosaurs ;-)
As many others have said, 1st check the fuel supply, 2nd check the fuel
supply and then check the fuel supply. If no joy then move deeper into
diagnosing problem. Simple easy solutions first then progress to the more
difficult ones.
As always YMMV....
Dave & Nancy
Swan Song
Roughwater 58
Limin in Waikiki Beach
_______________________________________________
Ken Bloomfield
In my observations, a generator will slow down under load. How cannot
it not? It is like driving your car up a hill. In fact, Northern Lights
told me long ago that when their generator is properly loaded it will
slow down to the point where it is producing electricity at 59 hertz. 58
is fully loaded and 57 means you are about to stall.
Eric,
While it is true that there can be a slight slow down in RPM, the design
objective was to reduce this to as near zero as possible. Your
comparison of driving a car up a hill is not quite valid. Automobiles,
at least gas engine ones, are fed a constant amount of fuel for a given
gas pedal depression. If you hold your foot steady at a certain pedal
depression (i.e. amount of "gas"), as you state -- the car and thus the
engine will slow down with the increasing load of going up a hill.
However, diesel and gasoline generator engines are controlled by a
governor, and not a "throttle". When you give your boat a certain
amount of "throttle" (misnomer) the governor is told to achieve a
certain RPM and it commences to give fuel to achieve that end.
Similarly, the genset is "told" to achieve a set RPM that will produce
the nominal 60HZ frequency. Once achieved, if the loading on the
generator increases, the governor sees this tendency to reduce RPM and
feeds more fuel to the engine, thus restoring the RPM to the nominal
value. Most of all these older generators (and many new ones) achieve
this at an RPM of 1800. However, even though the governor does a pretty
good job of not significantly slowing down (i.e. less than 5%) the
voltage would vary (decrease with load) if there were no additional
voltage regulation. In an old Onan like ours, this is done with a
simple saturable reactor (a passive design) that while imperfect in
voltage regulation, is pretty bullet-proof.
Ken Bloomfield
www.tellicolady.com
Marty Campanella
frequency standpoint for several years now.
On Bay Pelican we have a 8kw Westerbeke generator (1985). When the
generator is started the immediate load is about 200 watts consisting of
refrigeration and other minor items. If this is all that is drawing power
the generator output is at 61hz (deliberately set there by me). When I turn
on the first charger (100amps) the output drops to 60hz/59hz, when the
second charger (135amps) is added the output drops to 59hz. If I add the
electric dryer (2000 watts), the output drops to 58/57hz. At 57hz my dryer
will not operate. There are slight variations of this pattern depending on
what else is running on the boat, coffee pot, refrigeration defrost, but the
pattern has been consistent for several years now and I have learned to live
with it. During this period of time the genset has been serviced, the
injectors changed and it appears to be running well.
Marty Campanella
Bay Pelican KK42
Phil Bolin
My experience indicates you have a problem somewhere in generator. My 8 KW
ONAN keeps 60 hz +- 2 up to a load of 75 amps, as it should. It's an old
ONAN but works like a champ and I can run everything on the boat. If
designed correctly for your boat everything should run on the generator with
generator keeping proper frequency.
Phil
Snip:
On Bay Pelican we have a 8kw Westerbeke generator (1985). When the
generator is started the immediate load is about 200 watts consisting of
refrigeration and other minor items. ... At 57hz my dryer will not operate.
I have learned to live
with it.
Dave Legrow
Dave
Joe & Mary MANELIS
Now I'm faced (over this winter) of correcting this. Should we attempt to just shorten the old mast and hope the rest of it's OK, or maybe have a new aluminum mast made OR perhaps find an old mast out there that someone wants to get rid of.
Any suggestion would be appreciated.
Jos. J. MANELIS
Be the kind of person that when your feet hits the ground each morning the devil says,
"OH CRAP, HE'S UP"!
Email sent from my iPhone.
Bob McLeran
recommend replacing your rotted wooden mast with one made of aluminum.
It makes the lowering job a lot easier and one person could do it (if
it's stepped in a tabernacle). If nothing else, aluminum reduces your
topside weight substantially.
A used aluminum sailboat mast can be used and the appropriate fittings
you'll need added by any competent rigger.
I went through this recently on our DeFever 41. The mast itself weighs
over 250 pounds! We elected to keep the wooden mast only because I
didn't have time to replace it prior to departing for Canada and was
able to rig a six-part block and tackle arrangement so the two of us
could lower and raise the mast when necessary.
<><><><><><><><><><><><>Mozilla Thunderbird<><><><><><><><><><>
Bob McLeran and Judy Young Manatee Cove Marina
MV Sanderling Patrick Air Force Base
DeFever 41 Trawler Melbourne, Florida
Blog: http://sanderling2011.blogspot.com/
Pics: http://tinyurl.com/yjx2vky& http://tinyurl.com/yhxjvas
On 10/18/2011 9:31 AM, Joe & Mary MANELIS wrote:
> As we were stepping the mast on FOREVER YOUNG (1986 Marine Trader 44' aft cabin) it became very clear that the masts wooden interior was rotten to the core at the base. The mast crashed down luckily with NO injuries and no other damage to the boat.
>
> Now I'm faced (over this winter) of correcting this. Should we attempt to just shorten the old mast and hope the rest of it's OK, or maybe have a new aluminum mast made OR perhaps find an old mast out there that someone wants to get rid of.
_______________________________________________
Mark Richter
It should be easy to find an aluminum mast that could be modified to fit
your trawler. Many sailboat masts that break are still plenty long for a
trawler mast, and are available inexpensively at boat yards or through
listings on Craigslist or Ebay. I bought the heavy aluminum 22' long mast
for Winnie the Pooh at a boatyard in West Palm Beach for $200 (in 1996).
Mark Richter, Ortona, FL on the Okeechobee Waterway
General boat repairs at my dock or yours.
Electrical system design, installation and repair.
----- Original Message -----
Sent: Tuesday, October 18, 2011 9:31 AM
Subject: T&T: Mast goes boom !
> As we were stepping the mast on FOREVER YOUNG (1986 Marine Trader 44' aft
> cabin) it became very clear that the masts wooden interior was rotten to
> the core at the base. The mast crashed down luckily with NO injuries and
> no other damage to the boat.
>
> Now I'm faced (over this winter) of correcting this. Should we attempt to
> just shorten the old mast and hope the rest of it's OK, or maybe have a
> new aluminum mast made OR perhaps find an old mast out there that someone
> wants to get rid of.
>
> Any suggestion would be appreciated.
>
> Jos. J. MANELIS
dick...@comcast.net
Greetings! We had no mast on our 34' trawler when we bought her as the mast has also rotted. To solve the problem we acquired a used mast from a boat junkyard located in Baltimore. As we shopped for a mast, and corresponding boom, we visited several boatyards that favored sailboats and found several that had masts that would work. Cost won out and we got ours from the junkyard. We had to purchase the rigging to go with it of course but also found that used at a place in Annapolis.
Prior to buying the mast and setting it up we researched the old mast that went on the boat to begin with to get the proper height, etc. We also wanted the mast to be able to lift the weight of an adult our ot the water. Its importnat to check the tabernacle and roof to ensure it was not rotten and could take the weight of the mast and spreader lights, radar, etc. that you might want to hang on it. A friend of mine had one built for his trawler and it ran over $1000 to give you some idea if you decided to go that way. Good luck with it!
Dick Masse
St. Leonard, MD
----- Original Message -----
From: "Joe & Mary MANELIS" <forevery...@aol.com>
To: traw...@lists.trawlering.com
Sent: Tuesday, October 18, 2011 9:31:16 AM
Subject: T&T: Mast goes boom !
Chuck Hanson (Yahoo)
generator always performed flawlessly until one day the magneto gave out. I
replaced the magneto and the generator ran beautifully until I started to
load it up. The symptoms were that the engine began to bog down and finally
stalled as I approached 40 amps output. I found that the timing was off just
a little. When it was adjusted properly, the generator was back to normal
capacity and I was once again a happy boater.
Chuck Hanson