TWL: Dual high output alternators
I am planning to add dual high output alternators. I plan to leave the
existing 70 amp alternators to charge individual engine start batteries, and
connect the new high output alternators in parallel to charge the ship
supply.
Ship battery bank is 1100 amp hour, thus can accommodate between 250 and 300
amps charge current.
This subject has been previously discussed. Arild posted last July,
suggesting the use of the Balmar CenterFielder, but also stated that the
field wire could be paralleled, if both alternators were driven from the
same engine. I would have the alternators on separate engines, and (at
least initially) not have engine synchronizers. Prefer two "medium power"
alternators rather than one huge alternator, for redundancy and to balance
the load on the engines.
Threads in July 01 and 02 on this subject.
Looking at the Balmar alternators, regulators, and centerfielder, with 135
amp alternators, the total cost would come close to 2 BU.
I talked with Battery Shack, Marathon Florida (as recommended on the
thread). They can supply 145 amp alternators with built in three stage
regulators, and state that they will run fine in parallel without any added
connection between the two. He stated to not expect more than 130 amps
charge out of the 145 amp "rated" unit.
If Battery Shack is correct, the total solution would run about 2/3 BU.
Other than previous discussion, can anyone add advice on this subject: is
the Balmar solution overkill, and will running two identical alternators in
parallel work, as stated by Battery Shack?
Added question: any source of "off the shelf" mounts for the alternator to
Perkins Saber M135 engines (6 cyl, 365 cu inch). Battery Shack states that
the mount is "double foot, 4 inch space".
Thank you for your help and advice.
Chet
At 09:10 PM 1/7/03 -0500, you wrote:
I am planning to add dual high output alternators. I plan to leave the
existing 70 amp alternators to charge individual engine start batteries, and
connect the new high output alternators in parallel to charge the ship
supply.
I can't recall the source, but I have seen some nice large frame, 250 amp
alternators for about $700 each.
These used external DIODES & regulator which cuts down on heat, improved
output is the result.
Capt. Mike Maurice
Wilsonville, Near Portland Oregon
-----Original Message-----
From: trawler-world-list-admin@lists.samurai.com
[mailto:trawler-world-list-admin@lists.samurai.com]On Behalf Of Chet
Brummett
Sent: Tuesday, January 07, 2003 6:11 PM
To: trawler-world-list@lists.samurai.com
Subject: TWL: Dual high output alternators
I am planning to add dual high output alternators. I plan to leave the
existing 70 amp alternators to charge individual engine start batteries, and
connect the new high output alternators in parallel to charge the ship
supply.
Looking at the Balmar alternators, regulators, and centerfielder, with 135
amp alternators, the total cost would come close to 2 BU.
I talked with Battery Shack, Marathon Florida (as recommended on the
thread). They can supply 145 amp alternators with built in three stage
regulators, and state that they will run fine in parallel without any added
connection between the two. He stated to not expect more than 130 amps
charge out of the 145 amp "rated" unit.
If Battery Shack is correct, the total solution would run about 2/3 BU.
REPLY
Chet
It is possible to use the centerfielder on other brands of alternators, not
just Balmar.
They will work on any externally regulated alternator.
However I have personally seen a major installation with two large frame
alternatos driven by two engines and the whole setup ended up being an
unmitigated disasater. I stood and watched the ammeters fluctuated by 50 -
75 amps and finally one alternator shut down and the other carried the whole
load. That owner burned out four alternators in less than two months.
Finally when the centerfielder was installed we tamed the system. Even so it
still required fine tuning to get it working.
The boat had two 1000 amp hour banks located outboard to port and starboard
but they were hard wired together with no means of disconneting the two
halves. I measured a cable lenght difference of 16 feet leading to the two
banks. This cable resistance was sufficient to cause imbalances in the
identical regulators and alternators.
The secret to success is not necesaarily the actual brand of alternator but
in the control system located in the regulator and centerfielder.
The internal 3 stage regulator offered by Battery Shack sound like they
sense the battery voltage right at the alternator. This could be a problem
depending on how the rest of the system is cabled.
Whatever regulator you use they must have remote sensing ability so they
measure the battery terminal voltage at the post and both measure the exact
same voltage. The regulators must also have temperature sensing for both the
battery and the alternator case.
In addition I would strongly recommend that you incorporate means of
disconnecting the parts of the bank so you can isolate a bad section should
a fault develop. When you getinvolved in battery banks of this size the
potential for a major meltdown is considerable.
Before you make any purchase decision ask to see the engineering details
concerning each of the potential alternators you are considering.
Look at how each handle internal cooling - fans and slots for air flow. Look
at the heat sinks for the rectifiers. Mass size and amount of dissipation
fins.
Ask to seethe hot rating curves and if possible get an indication of how the
units perform after running at max temp for four or five hours.
Remember the Cruising World comparison of a Balmar and Ample Power
alternator.
Despite superior numbers for the early part of the test, the Ample Power
alternator was running hotter after several hours indicatging it did not
have as good a means of dissipating accumulated heat.
As for the centerfielder versus two independent regulators. This product was
developed in response to the exact problem created in installations such as
you contemplate. It was actually a diesel engine manufacturer who requested
it after finding problesm with their new engine installations. This is not
a highly publicized gimmick product intended to bilk the public out of many
dollars.
It is an engineering solution to a technical problem.
Whichever brand you eventually do pick, I would make very sure you also
provide means of monitoring the alterntor case temperature and the
individual output currents. Have in place suitable disconnect switches so
you can isolate one half or the other if problems develop.
At least this way, your whole vessel will not be crippled.
Good luck
Arild
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.423 / Virus Database: 238 - Release Date: 11/25/2002
I talked with Battery Shack, Marathon Florida (as recommended on the
thread). They can supply 145 amp alternators with built in three stage
regulators, and state that they will run fine in parallel without any added
connection between the two. He stated to not expect more than 130 amps
charge out of the 145 amp "rated" unit.
If Battery Shack is correct, the total solution would run about 2/3 BU.
Chet
I have posted here previously my personal experience with the Battery Shack
alternators with internal regulators. I had three of the alternators fail
in fairly short order, each time with the internal regulator being the
problem. The company owner was always quite accomodating and replaced the
alternator without question. The last time I asked that he send their
alternator configured for external regulator and thus far that combination
has worked perfectly, though without a lot of engine hours to date. I am
using a Xantrex
3 stage regulator.
I have the impression that the Battery Shack alternator is a good product
at a very fair price, from a small company that is quite satisfying to deal
with. I am currently quite dubious about the durability of their internal
regulator.
The output the owner estimated would parallel my experience, with a peak
output of 70-75 amps from their
100 amp rated alternator.
Dan Stone
M/V Slow Dance
Albin 43
St. Petersburg, FL
While looking at all the various wire for sale, I
wondered if "marine rated wire" is really any
different than just plain old wire with no fancy
packaging and no marine rating, and some that is not
stamped with the AWG number on it? And if it is
different, what exactly is the difference?
Dan
37 Roughwater
=====
Do you Yahoo!?
Yahoo! Mail Plus - Powerful. Affordable. Sign up now.
http://mailplus.yahoo.com
Most wire for marine use should be fine stranded (for flexibility
to reduce cracking) and tinned (to reduce corrosion).
Oil-resistance of the insulation is a good idea, too, but most
wire you find will have oil resistant insulation (the insulation
codes, like "THHN" provide this information). Insulation should
be rated for at least 90 C, but I prefer that rated for 105 C.
Some insulations have their temperature rating degraded if wet
(this info is printed right on the wire)
I have run across wire marked "Marine" which was not tinned, so
don't give too much credence to wire so marked or marketed. A
good and reasonably priced source for marine wire is Jamestown
Distributors, in RI. No connections.
=====
Mark Richter, M.E., aboard M/V Winnie the Pooh,
custom Morgan 46 Pilothouse Efficiency Trawler.
"Mark's Mobile Marine" electrical systems repair & consulting. Homeport Stuart, FL
Do you Yahoo!?
Yahoo! Mail Plus - Powerful. Affordable. Sign up now.
http://mailplus.yahoo.com
Dan asked
While looking at all the various wire for sale, I
wondered if "marine rated wire" is really any
different than just plain old wire with no fancy
packaging and no marine rating, and some that is not
stamped with the AWG number on it? And if it is
different, what exactly is the difference?
REPLY - belated
Dan's question deserves a more qualified answer that what has been posted so
far.
Mark is absolutely correct regarding the temp rating and insulation type.
However the real "marine" certification goes beyond that.
I have seen a lot of wire labelled "Marine" in various stores but closer
examination reveals this to be only a marketing ploy.
It was also mentioned that SAE wire is slightly smaller than the equivalent
gage according to AWG standards.
Insulation type not just temp ratring is very important.
A few years ago I read of a death which occurred when a boat owner was
wiring up some 12V circuit.
He accidentally placed a short circuit across the relatively small sailboat
battery.
The six foot lenght of wire inmmediately overheated and smoked the
insulation.
The toxic fumes released by this overheated insulation overcame the person
before he could reach the companionway four steps away.
Turns out he had used some no name automotive wire bought at a discount
place.
Flammability, toxic smoke release and immunity to normal chemicals found on
board as well as insulation resistance are all part of the criteria being
considdered when certifying a particular wire and insulation for marine use.
This is why I am very uncomfortable about using any unmarked wire on board a
boat.
Ampacity and flexibility are only two of many criterion that determines if a
given wire is suitable.
I would also like to point out that soldering fine stranded wires may not
be the4 best idea.
When the solder fuses all those fine strands into a solid lump a hard
bending point is created.
If any flexing or vibration causes movement of the wire then this is where
the wire will break.
The only way to eliminate such breakage is to firmly restrain the cable
from moving at all.
Crimping a wire into a crimp sleeve does not produce such a hard spot and
the insulated sleeve normally acts as a strain relief and flexure restriant
to further reduce the possibility of breakage.
In addition, the soldering process, especially on larger cables tends to
damage the insulation with excess heat.
To prevent moisture from wicking up into the insulation I suggest using some
sort of dielectric paste, silicon grease of something from the electrical
supplier for use as an antioxidant.
Remember also that a rubber cable may be rated for outdoor use in wet
locations but ozone (bilge busters) can harm the rubber even when dry.
Regards
Arild
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.423 / Virus Database: 238 - Release Date: 11/25/2002
Crimping a wire into a crimp sleeve does not produce such a hard spot and
the insulated sleeve normally acts as a strain relief and flexure
restriant
to further reduce the possibility of breakage.
In addition, the soldering process, especially on larger cables tends to
damage the insulation with excess heat.
To prevent moisture from wicking up into the insulation I suggest using
some
sort of dielectric paste, silicon grease of something from the electrical
supplier for use as an antioxidant.
As always, Arild has given us some excellent advise. I would just like to
add a couple of things. The solderless terminal, or crimp sleeve, needs to
be properly made. This means using a ratcheting crimper matching the
crimper die to the terminal. The ratcheting crimper is designed to crimp
the sleeve to the copper wire AND the to the wire insulation for the strain
relief. The ratcheting crimper also makes the same crimp time after time
after time. The manual crimpers depend on the strength and stamina of the
operator. I believe ratcheting crimpers have been discussed before so a
check in the archives should provide some links.
In addition to using the dielectric paste and a ratcheting crimper, I have
also been using a piece of heat shrink tubing over the terminal sleeve. It
takes a bit if experimentation to get the proper size tubing for each
different size terminal, but when finished it makes a really good looking
termination, adds additional strain relief support, and makes the terminal
virtually waterproof. I started doing this for bilge pump wiring that was
close to the bilge water, and liked it so much I continued with it on all
wiring.
Regards,
Andy
Andy & Linda Woods
Grand Folly
1970 Grand Banks 36 Classic
Georgetown, MD
awoods@surfbest.net
Check out this site for more than you ever wanted to know about
terminals, crimpers, etc. Great products and tools as well, and a lot of
interesting how-to: http://www.terminaltown.com/
Andy Woods wrote:
<snip> The solderless terminal, or crimp sleeve, needs to
be properly made. This means using a ratcheting crimper matching the
crimper die to the terminal. The ratcheting crimper is designed to crimp
the sleeve to the copper wire AND the to the wire insulation for the strain
relief. The ratcheting crimper also makes the same crimp time after time
after time. <snip>
--
Keith
One nice thing about egotists: they don't talk about other people.