BoatBanter.com

BoatBanter.com (https://www.boatbanter.com/)
-   Electronics (https://www.boatbanter.com/electronics/)
-   -   Can an alternator be to big? (https://www.boatbanter.com/electronics/71728-can-alternator-big.html)

Glenn Ashmore July 14th 06 01:00 AM

Can an alternator be to big?
 
I have been offered a really good deal on a high amp (325 amp) fire engine
alternator by the city vehicle maintenance shop. It was purchased as a test
unit but due to some budget cutbacks ended up being to expensive to equip
the whole fleet. This monster is hot rated at 200 amps at 2,000 rpm and
275 amps at 4000 rpm. I am thinking about buying it and keeping the 200 amp
Leece Neville as a spare.

My battery bank is 850AH of L16HC wet cells that can take 200 amps in bulk
charge. Is my Xantrex smart regulator going to keep this monster from
cooking my battery bank?

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com



chuck July 14th 06 01:21 AM

Can an alternator be to big?
 
Glenn Ashmore wrote:
I have been offered a really good deal on a high amp (325 amp) fire engine
alternator by the city vehicle maintenance shop. It was purchased as a test
unit but due to some budget cutbacks ended up being to expensive to equip
the whole fleet. This monster is hot rated at 200 amps at 2,000 rpm and
275 amps at 4000 rpm. I am thinking about buying it and keeping the 200 amp
Leece Neville as a spare.

My battery bank is 850AH of L16HC wet cells that can take 200 amps in bulk
charge. Is my Xantrex smart regulator going to keep this monster from
cooking my battery bank?


A smart regulator should have no problem
at all with an over-size alternator. In
the end, the battery itself will
determine the rate at which it will
accept charge. With so large a bank and
so ample an alternator, a soft-start
feature on the regulator will add life
to your belt(s). And belts and slippage
may also limit charging current.

Chuck

----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----

Keith July 14th 06 01:53 AM

Can an alternator be to big?
 
Keep in mind that it'll probably take at least dual belts if not
toothed ones and suck up some horsepower from the engine. If it's
charging a lot while you go to idle, it could kill your engine. That
all being said, still sounds like a deal. Just have to get the right
control circuitry.
chuck wrote:
Glenn Ashmore wrote:
I have been offered a really good deal on a high amp (325 amp) fire engine
alternator by the city vehicle maintenance shop.



Glenn Ashmore July 14th 06 02:42 AM

Can an alternator be to big?
 
Don't think there will be a problem there. The alternator mount is already
set up for dual BX cogged belts which should be able to handle 12HP. I did
that because I didn't want that Leese Neville squealing. Because this thing
puts out a lot more amps at lower RPM than the LN I think I will increase
the pulley diameter which should increase the power handling capacity even
more.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"Keith" wrote in message
oups.com...
Keep in mind that it'll probably take at least dual belts if not
toothed ones and suck up some horsepower from the engine. If it's
charging a lot while you go to idle, it could kill your engine. That
all being said, still sounds like a deal. Just have to get the right
control circuitry.
chuck wrote:
Glenn Ashmore wrote:
I have been offered a really good deal on a high amp (325 amp) fire
engine
alternator by the city vehicle maintenance shop.





Andina Marie July 14th 06 08:50 PM

Can an alternator be to big?
 
I hope you were increasing both pulleys so the alternator RPM was the
same?

If the alternator sucks up too many horsepower, especially when docking
or emergencies, a field disconnect switch can be added to remove the
load temporarily.


Larry July 14th 06 09:13 PM

Can an alternator be to big?
 
chuck wrote in news:1152835959_12681
@sp6iad.superfeed.net:

And belts and slippage
may also limit charging current.



May?
..
..
..
..
..
WILL!

325A x 14V = 4550 watts divided by 746W/hp = 6.1 HP plus the conversion
losses, probably over 10HP.

How big was that Yanmar 2GM in that boat??....(c;

How many HP is a V-belt capable of delivering at 2000 RPM, anyways?

How many pulley Vs does the alternator's pulley have, if it has pulleys at
all?

Two fan belts are NOT going to pull a 200 or 325A alternator for long.....
It's hard enough to keep a 120A fan belt from squealing....


Glenn Ashmore July 15th 06 12:55 AM

Can an alternator be to big?
 
Actually reducing the alternator RPM is the idea. This thing puts out
200Amps at an alternator speed under 2000 RPM. With the pulleys I have now
that is an engine speed of about 800 RPM. I need to get the engine turning
faster or the power will be all torque and no speed and Larry's prediction
of gloom and doom might come true. A pair of BX belts can handle plenty of
HP but not at such low speeds.

After some research I found some interesting things about this monster.
There are actually two rotors on the same shaft. One is high power
permanent magnets and the other is a regular Lundell claw & field coil.
With the field coil off the magnets will drive the alternator to 200 amps at
4,000 RPM. If more power is needed to maintain voltage the field coil is
energized to add to the flux and produce up to 305 amps. If less power is
needed the coil is reversed to cancel out the flux field. Net result is a
70% increase in efficiency and a corresponding reduction in heat build up
but to get minimum output the field coil has to be driven at full power
backwards.

The down side is you can't use a 3 stage regulator. This puppy is designed
to crank out power for lights, inverters and equipment. Control is strictly
on the output voltage so it stays in bulk stage until the batteries can't
take any more. This is going to take some more thought. For the price
though it would be a good temporary high output spare.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"Andina Marie" wrote in message
ps.com...
I hope you were increasing both pulleys so the alternator RPM was the
same?

If the alternator sucks up too many horsepower, especially when docking
or emergencies, a field disconnect switch can be added to remove the
load temporarily.




Paul Hovnanian P.E. July 15th 06 05:32 AM

Can an alternator be to big?
 
Glenn Ashmore wrote:

Actually reducing the alternator RPM is the idea. This thing puts out
200Amps at an alternator speed under 2000 RPM. With the pulleys I have now
that is an engine speed of about 800 RPM. I need to get the engine turning
faster or the power will be all torque and no speed and Larry's prediction
of gloom and doom might come true. A pair of BX belts can handle plenty of
HP but not at such low speeds.


Actually, the alternator will put out whatever the battery and loads
require. Unless you are charging a huge battery bank and/or have 200 A
load connected to it, it won't put out that much. Given the electrical
(and mechanical) losses, the input HP will be whatever are needed to
provide the electrical output. The larger alternator will have lower
electrical losses, but higher mechanical. All in all, this unit won't
present a mechanical load significantly different than a smaller
alternator.

After some research I found some interesting things about this monster.
There are actually two rotors on the same shaft. One is high power
permanent magnets and the other is a regular Lundell claw & field coil.
With the field coil off the magnets will drive the alternator to 200 amps at
4,000 RPM. If more power is needed to maintain voltage the field coil is
energized to add to the flux and produce up to 305 amps. If less power is
needed the coil is reversed to cancel out the flux field. Net result is a
70% increase in efficiency and a corresponding reduction in heat build up
but to get minimum output the field coil has to be driven at full power
backwards.


This unit must be matched to the appropriate regulator. If you didn't
get one with the alternator, the deal may not have been that good.

The down side is you can't use a 3 stage regulator. This puppy is designed
to crank out power for lights, inverters and equipment. Control is strictly
on the output voltage so it stays in bulk stage until the batteries can't
take any more. This is going to take some more thought. For the price
though it would be a good temporary high output spare.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"Andina Marie" wrote in message
ps.com...
I hope you were increasing both pulleys so the alternator RPM was the
same?

If the alternator sucks up too many horsepower, especially when docking
or emergencies, a field disconnect switch can be added to remove the
load temporarily.


--
Paul Hovnanian
------------------------------------------------------------------
Klein bottle for rent -- inquire within

Glenn Ashmore July 15th 06 12:00 PM

Can an alternator be to big?
 

"Paul Hovnanian P.E." wrote

Actually, the alternator will put out whatever the battery and loads
require. Unless you are charging a huge battery bank and/or have 200 A
load connected to it, it won't put out that much. Given the electrical
(and mechanical) losses, the input HP will be whatever are needed to
provide the electrical output. The larger alternator will have lower
electrical losses, but higher mechanical. All in all, this unit won't
present a mechanical load significantly different than a smaller
alternator.


That's just it. There will definitely be a heavy load on it. When it
cranks up every morning it will be seeing a 900AH battery bank ready to take
the first 225 amps in bulk mode.

This unit must be matched to the appropriate regulator. If you didn't
get one with the alternator, the deal may not have been that good.


It has the regulator built in. Pretty interesting one too. Even has a
battery voltage sense connection. However the regulator does not have a way
to change from bulk to absorption to float modes and there is no
equalization. The shore power charger can handle the equalization and with
my normal use pattern of 50% to 85% charge will rarely need float except at
the dock but it would be nice to have optomized bulk and absorption ability.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com





Capt John July 16th 06 07:00 PM

Can an alternator be to big?
 

Glenn Ashmore wrote:
I have been offered a really good deal on a high amp (325 amp) fire engine
alternator by the city vehicle maintenance shop. It was purchased as a test
unit but due to some budget cutbacks ended up being to expensive to equip
the whole fleet. This monster is hot rated at 200 amps at 2,000 rpm and
275 amps at 4000 rpm. I am thinking about buying it and keeping the 200 amp
Leece Neville as a spare.

My battery bank is 850AH of L16HC wet cells that can take 200 amps in bulk
charge. Is my Xantrex smart regulator going to keep this monster from
cooking my battery bank?

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com


Everything you attach to the engine reduces the HP output. How much,
good question. But having an alternator that is far bigger than your
needs is a waste. Additionally, to make use of that power you need to
get it to the battery banks. If the wire between the alternator and
battery is too small to handle the current, or the wire between the
battery and load center (electrical pannel) is too small, it could burn
up under a heavy load if it's not fused properly. Your probably going
to end up cooking something, lets hope it's not the boat while your on
it. Also, if it's not CG approved, and you have a fire because of it,
your insurance company is going to walk away, it's your problem. I'd
stick with the normal marine alternator if I was you.

John


Glenn Ashmore July 16th 06 08:22 PM

Can an alternator be to big?
 

"Capt John" wrote

Everything you attach to the engine reduces the HP output. How much,
good question. But having an alternator that is far bigger than your
needs is a waste. Additionally, to make use of that power you need to
get it to the battery banks. If the wire between the alternator and
battery is too small to handle the current, or the wire between the
battery and load center (electrical pannel) is too small, it could burn
up under a heavy load if it's not fused properly. Your probably going
to end up cooking something, lets hope it's not the boat while your on
it. Also, if it's not CG approved, and you have a fire because of it,
your insurance company is going to walk away, it's your problem. I'd
stick with the normal marine alternator if I was you.


No real problem there. Because if the higher efficiency the HP charts say
it will take less power than the 200A Leese Neville that is in there now. I
have 4/0 to the 850AH bank and the inverter and 2/0 to the breaker panel.
At idle speed it will theoretically put out up to 240 amps which will cover
the 225A the battery bank needs in bulk mode with a little left over for
house loads.

The alternator is an Eco Tech 305. Apparently they are becoming popular
with the commercial fishing boats in the NW. The regulator is set for 14.4
volts so while it may take a little longer in bulk mode it will be just
right for absorption. I just need to figure a way to turn it off when
motoring through a couple of days of no wind. Not a good idea to hold a
fully charged battery at 14.4V for very long.

Go2Marine has them on their site listed at $2K. The city is asking $375. I
think I am going to take them up on it. :-)


--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com



Larry July 16th 06 09:44 PM

Can an alternator be to big?
 
"Capt John" wrote in news:1153072859.862252.17460
@p79g2000cwp.googlegroups.com:

Also, if it's not CG approved, and you have a fire because of it,
your insurance company is going to walk away, it's your problem. I'd
stick with the normal marine alternator if I was you.



I think THAT is a very important point, too....





---------
Press 1 for English
Press 2 to disconnect until you learn English

GBM July 17th 06 01:20 AM

Can an alternator be to big?
 
There used to be a manual alternator regulator called an Automac, sold by
Weems & Plath - This allowed the alternator output to be manually adjusted.
These are no longer sold, but perhaps someone else sells something like
that? Or perhaps drive it through a clutch that can be disengaged and keep
a smaller alternator in service?

I can understand that the price is attractive, but I would be careful with
that beast! Unless of course, if you plan on doing some welding ;) Usually
better to have multiple smaller units. Ventilation and cooling may need to
be addressed - will you get enough cooling in your engine room as compared
with the intended installation for those units?

BUT, if you have the HP to drive it, it does sound like an interesting
unit - especially the low speed output.

GBM

"Glenn Ashmore" wrote in message
news:ulwug.165$ok5.148@dukeread01...


No real problem there. Because if the higher efficiency the HP charts say
it will take less power than the 200A Leese Neville that is in there now.

I
have 4/0 to the 850AH bank and the inverter and 2/0 to the breaker panel.
At idle speed it will theoretically put out up to 240 amps which will

cover
the 225A the battery bank needs in bulk mode with a little left over for
house loads.

The alternator is an Eco Tech 305. Apparently they are becoming popular
with the commercial fishing boats in the NW. The regulator is set for

14.4
volts so while it may take a little longer in bulk mode it will be just
right for absorption. I just need to figure a way to turn it off when
motoring through a couple of days of no wind. Not a good idea to hold a
fully charged battery at 14.4V for very long.

Go2Marine has them on their site listed at $2K. The city is asking $375.

I
think I am going to take them up on it. :-)


--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com





Glenn Ashmore July 17th 06 04:33 AM

Can an alternator be to big?
 
This thing uses a J-180 mount same as the Leece Neville so it will basically
be a drop in. Also supposed to generate less heat so the duct work I
installed for the LN should be more than adequate.

The weird thing about this alternator is that the primary magnetic field is
from the permanent magnets on the rotor so as long as it is turning it is
generating power. The way you turn it off is to run the field current in
reverse to cancel out the magnets. That greatly increase the efficiency but
means it can't use a normal external regulator.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"GBM" wrote in message
...
There used to be a manual alternator regulator called an Automac, sold by
Weems & Plath - This allowed the alternator output to be manually
adjusted.
These are no longer sold, but perhaps someone else sells something like
that? Or perhaps drive it through a clutch that can be disengaged and
keep
a smaller alternator in service?

I can understand that the price is attractive, but I would be careful with
that beast! Unless of course, if you plan on doing some welding ;)
Usually
better to have multiple smaller units. Ventilation and cooling may need
to
be addressed - will you get enough cooling in your engine room as compared
with the intended installation for those units?

BUT, if you have the HP to drive it, it does sound like an interesting
unit - especially the low speed output.

GBM

"Glenn Ashmore" wrote in message
news:ulwug.165$ok5.148@dukeread01...


No real problem there. Because if the higher efficiency the HP charts
say
it will take less power than the 200A Leese Neville that is in there now.

I
have 4/0 to the 850AH bank and the inverter and 2/0 to the breaker panel.
At idle speed it will theoretically put out up to 240 amps which will

cover
the 225A the battery bank needs in bulk mode with a little left over for
house loads.

The alternator is an Eco Tech 305. Apparently they are becoming popular
with the commercial fishing boats in the NW. The regulator is set for

14.4
volts so while it may take a little longer in bulk mode it will be just
right for absorption. I just need to figure a way to turn it off when
motoring through a couple of days of no wind. Not a good idea to hold a
fully charged battery at 14.4V for very long.

Go2Marine has them on their site listed at $2K. The city is asking $375.

I
think I am going to take them up on it. :-)


--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com







chuck July 17th 06 12:17 PM

Can an alternator be to big?
 
Larry wrote:
"Capt John" wrote in news:1153072859.862252.17460
@p79g2000cwp.googlegroups.com:

Also, if it's not CG approved, and you have a fire because of it,
your insurance company is going to walk away, it's your problem. I'd
stick with the normal marine alternator if I was you.



I think THAT is a very important point, too....


Doesn't the CG requirement kick in only
for gasoline engines? I doubt the
insurance company could walk if the
engine is diesel.

Chuck

Capt John July 17th 06 07:03 PM

Can an alternator be to big?
 

chuck wrote:
Larry wrote:
"Capt John" wrote in news:1153072859.862252.17460
@p79g2000cwp.googlegroups.com:

Also, if it's not CG approved, and you have a fire because of it,
your insurance company is going to walk away, it's your problem. I'd
stick with the normal marine alternator if I was you.



I think THAT is a very important point, too....


Doesn't the CG requirement kick in only
for gasoline engines? I doubt the
insurance company could walk if the
engine is diesel.

Chuck



Capt John July 17th 06 07:18 PM

Can an alternator be to big?
 

chuck wrote:
Larry wrote:
"Capt John" wrote in news:1153072859.862252.17460
@p79g2000cwp.googlegroups.com:

Also, if it's not CG approved, and you have a fire because of it,
your insurance company is going to walk away, it's your problem. I'd
stick with the normal marine alternator if I was you.



I think THAT is a very important point, too....


Doesn't the CG requirement kick in only
for gasoline engines? I doubt the
insurance company could walk if the
engine is diesel.

Chuck


The CG requirement is for diesel as well, diesel fuel burns quite well.
Cracked high pressure diesel fuel lines can produce a very fine fuel
mist, and it makes for one hell of a fire if it hits a spark or a hot
dry turbo. Give an insurance company an excuse to walk away from paying
on a loss and watch how fast they run. That's what they pay their
people to do. I looked quickly at my Cat alternator part numbers, they
look like differant part numbers than the truck numbers in the catalog.
It just isn't worth it.


Glenn Ashmore July 17th 06 07:59 PM

Can an alternator be to big?
 
The surveyor that my insurance company hired to monitor my progress has seen
the Leese Neville which is not "USCG approved" and accepted it with out
reservation.

Actually neither 46 CFR 176 or 46 CFR 183 require approval of alternators in
diesel powered environments. The only source I can find that recommends
using only marine approved alternators is our friend David Pasco and he even
has the reference to the requirements wrong. J1527 is specific to hose
standards, not alternators.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"Capt John" wrote in message
ups.com...

chuck wrote:
Larry wrote:
"Capt John" wrote in news:1153072859.862252.17460
@p79g2000cwp.googlegroups.com:

Also, if it's not CG approved, and you have a fire because of it,
your insurance company is going to walk away, it's your problem. I'd
stick with the normal marine alternator if I was you.



I think THAT is a very important point, too....


Doesn't the CG requirement kick in only
for gasoline engines? I doubt the
insurance company could walk if the
engine is diesel.

Chuck


The CG requirement is for diesel as well, diesel fuel burns quite well.
Cracked high pressure diesel fuel lines can produce a very fine fuel
mist, and it makes for one hell of a fire if it hits a spark or a hot
dry turbo. Give an insurance company an excuse to walk away from paying
on a loss and watch how fast they run. That's what they pay their
people to do. I looked quickly at my Cat alternator part numbers, they
look like differant part numbers than the truck numbers in the catalog.
It just isn't worth it.




chuck July 17th 06 08:19 PM

Can an alternator be to big?
 
Capt John wrote:
chuck wrote:
Larry wrote:
"Capt John" wrote in news:1153072859.862252.17460
@p79g2000cwp.googlegroups.com:

Also, if it's not CG approved, and you have a fire because of it,
your insurance company is going to walk away, it's your problem. I'd
stick with the normal marine alternator if I was you.


I think THAT is a very important point, too....

Doesn't the CG requirement kick in only
for gasoline engines? I doubt the
insurance company could walk if the
engine is diesel.

Chuck


The CG requirement is for diesel as well, diesel fuel burns quite well.
Cracked high pressure diesel fuel lines can produce a very fine fuel
mist, and it makes for one hell of a fire if it hits a spark or a hot
dry turbo. Give an insurance company an excuse to walk away from paying
on a loss and watch how fast they run. That's what they pay their
people to do. I looked quickly at my Cat alternator part numbers, they
look like differant part numbers than the truck numbers in the catalog.
It just isn't worth it.


Capt. John, I'd really like to see a
cite for the specific USCG regulation
that requires ignition-protected
alternators on diesel engines. 33 CFR
183.410 addresses only gasoline, and
even then gives a pass if the gasoline
is on the other side of a bulkhead, etc.

Here is the applicability paragraph
(183.401) for ignition protection:

(a) This subpart applies to all boats
that have gasoline engines, except
outboard engines, for electrical
generation, mechanical power, or propulsion.


FWIW, I'm not advocating anything and am
making no judgment here on what is and
isn't worth it. I'm simply seeking
clarification on what the regs actually
say.

Chuck

----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----

Peter Albright July 19th 06 01:30 AM

Can an alternator be to big?
 
Glen,

Have you considered biasing the voltage sense line, to adjust the regulator
output voltage?

Peter Albright,
Tampa, FL
"Glenn Ashmore" wrote in message
news:BV3ug.44$ok5.9@dukeread01...

"Paul Hovnanian P.E." wrote

Actually, the alternator will put out whatever the battery and loads
require. Unless you are charging a huge battery bank and/or have 200 A
load connected to it, it won't put out that much. Given the electrical
(and mechanical) losses, the input HP will be whatever are needed to
provide the electrical output. The larger alternator will have lower
electrical losses, but higher mechanical. All in all, this unit won't
present a mechanical load significantly different than a smaller
alternator.


That's just it. There will definitely be a heavy load on it. When it
cranks up every morning it will be seeing a 900AH battery bank ready to
take the first 225 amps in bulk mode.

This unit must be matched to the appropriate regulator. If you didn't
get one with the alternator, the deal may not have been that good.


It has the regulator built in. Pretty interesting one too. Even has a
battery voltage sense connection. However the regulator does not have a
way to change from bulk to absorption to float modes and there is no
equalization. The shore power charger can handle the equalization and
with my normal use pattern of 50% to 85% charge will rarely need float
except at the dock but it would be nice to have optomized bulk and
absorption ability.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com







Glenn Ashmore July 19th 06 02:42 AM

Can an alternator be to big?
 

"Peter Albright" wrote in message
news:u2fvg.14644$A8.3191@trnddc02...
Glen,

Have you considered biasing the voltage sense line, to adjust the
regulator output voltage?


I have been thinking about that. Looks like that would be the only way to
control it. The internal regulator is set to maintain 14.4V on the sense
line. Boosting the sense line 1.2V would bring the output down to a safe
13.2V float. You could actually put a microprocessor to sense the battery
voltage and bias the alternator sense to do everything a "smart" regulator
does but that would be more work than I have time for.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com



Paul Hovnanian P.E. July 21st 06 01:36 AM

Can an alternator be to big?
 
Glenn Ashmore wrote:

"Paul Hovnanian P.E." wrote

Actually, the alternator will put out whatever the battery and loads
require. Unless you are charging a huge battery bank and/or have 200 A
load connected to it, it won't put out that much. Given the electrical
(and mechanical) losses, the input HP will be whatever are needed to
provide the electrical output. The larger alternator will have lower
electrical losses, but higher mechanical. All in all, this unit won't
present a mechanical load significantly different than a smaller
alternator.


That's just it. There will definitely be a heavy load on it. When it
cranks up every morning it will be seeing a 900AH battery bank ready to take
the first 225 amps in bulk mode.

This unit must be matched to the appropriate regulator. If you didn't
get one with the alternator, the deal may not have been that good.


It has the regulator built in. Pretty interesting one too. Even has a
battery voltage sense connection. However the regulator does not have a way
to change from bulk to absorption to float modes and there is no
equalization. The shore power charger can handle the equalization and with
my normal use pattern of 50% to 85% charge will rarely need float except at
the dock but it would be nice to have optomized bulk and absorption ability.


That could be a problem. If you could tweak the voltage setting down a
bit, you could slow down the battery charge rate and the resulting
engine load.

Petes's suggestion is pretty good. Put in some current sensing on the
gen. output and use that to bump the V sense line up as the generator
output approaches a setting suitable to your prime mover. You'll need a
gain control to set the V bias per amp load and set it so that the
system remains stable.

--
Paul Hovnanian
------------------------------------------------------------------
Have a pleasant Terran revolution.


All times are GMT +1. The time now is 08:21 PM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004 - 2014 BoatBanter.com