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

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

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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.

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.

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.

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....

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.

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

"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 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