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Author Topic: Alternator shopping, Looking for amperage advice  (Read 189 times)

ricknc

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Alternator shopping, Looking for amperage advice
« on: October 12, 2018, 10:47:55 AM »
Stock 105amp Alternator has been struggling lately(1995 Warrior  w/454). The other night I was sitting in traffic and it was hot out so  between the A/C ,headlights, engine cooling fan and the engine itself the alternator was struggling to make 13 volts. I also want to start using an inverter (1500w PSW) to run the fridge(200 watts) and occasionally the hot water heater probe(400 watts) while traveling.
Considering the Inverter DC draw for the fridge and H/W will be draw 60 amp on the batteries and the chassis  probably needs another 20 or 30 amps. I'm guessing 200 amps would be sufficient?  What do you all suggest based on experience? Also what are some recommended brands or sources?

John Canfield

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Re: Alternator shopping, Looking for amperage advice
« Reply #1 on: October 13, 2018, 07:54:10 AM »
Is the alternator working properly? Putting out the required current? What's the condition of your chassis batteries? I think the alternator on my diesel pusher Horizon in rated for 180 amps, but I don't remember for sure. Whatever the size, it's plenty to run my Magnum PSW inverter and residential fridge (which doesn't draw very much current.)
--John
2005 Horizon 40AD, 2006 Jeep Rubicon Unlimited
Our Horizon projects
Our weather

Alfa38User

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Re: Alternator shopping, Looking for amperage advice
« Reply #2 on: October 13, 2018, 08:30:22 AM »
If possible, drop the load requirement of the water heater by running it on propane.
Stu
Montréal, Canada 🍁
Snowbird, Naples Florida
Alfa Gold 38 (2000) 5ver (parked!)

"Of course I talk to myself, sometimes I need expert advise!!!"

Gary RV_Wizard

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Re: Alternator shopping, Looking for amperage advice
« Reply #3 on: October 13, 2018, 10:11:28 AM »
It is doubtful that the wiring can actually utilize 200A but it doesn't hurt to have excess capacity.  Remember that is a peak output and at idle or low speeds the output is nowhere near that high.

Chances are your existing alternator has a failed diode and is not putting out its rated current, but if you are going to repalce it anyway, may as well get 140+ amps.

My previous Class A DP had a Leece-Neville 180A alternator.
Gary
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Gary Brinck
Summers: Black Mountain, NC
Home: Ocala National Forest, FL

ricknc

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Re: Alternator shopping, Looking for amperage advice
« Reply #4 on: October 13, 2018, 10:24:11 AM »
Is the alternator working properly? Putting out the required current? What's the condition of your chassis batteries? I think the alternator on my diesel pusher Horizon in rated for 180 amps, but I don't remember for sure. Whatever the size, it's plenty to run my Magnum PSW inverter and residential fridge (which doesn't draw very much current.)

John, I doubt that the 23 year old alternator is living it to it's full potential. Chassis Battery is one year old. Coach batteries are not charged by the engine.  I'll remove the alternator next week and have it tested for output.   The 180 amp in your bus is a good bench mark for me so I'll look in that range. The optional GM/Delco alternator series(cs130) used with that engine AFAIK goes up to 124 amps, so everything beyond that is an aftermarket rewind of the original or  an adaptation of a larger case Delco alternator(cs144).

The fridge is a 6 y rold dometic absorption. works fine for us within it's limitations. May go with a residential type if and when this one dies.

Stu. I use mostly 110 power for the HW and propane off the grid. Using the inverter is just for those times when neither is convenient or available.

John Canfield

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Re: Alternator shopping, Looking for amperage advice
« Reply #5 on: October 13, 2018, 11:45:01 AM »
There's most likely a limit on how large of an alternator your belt (serpentine or regular V belt) can turn. On our last sailboat I had a high output Balmar alternator which the 1/2" wide engine belt struggled to turn at full alternator output. I had to use spray belt dressing quite often to keep the belt from spinning on the alternator pulley.
--John
2005 Horizon 40AD, 2006 Jeep Rubicon Unlimited
Our Horizon projects
Our weather

cbeierl

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Re: Alternator shopping, Looking for amperage advice
« Reply #6 on: October 13, 2018, 11:59:55 AM »
... I think the alternator on my diesel pusher Horizon in rated for 180 amps, but I don't remember for sure. Whatever the size, it's plenty to run my Magnum PSW inverter and residential fridge (which doesn't draw very much current.)
John, I'm pretty sure we both have a 160A alternator.
Chris Beierl
2005 Winnebago Vectra 36RD

ricknc

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Re: Alternator shopping, Looking for amperage advice
« Reply #7 on: October 13, 2018, 12:18:40 PM »
It is doubtful that the wiring can actually utilize 200A but it doesn't hurt to have excess capacity.  Remember that is a peak output and at idle or low speeds the output is nowhere near that high.

Chances are your existing alternator has a failed diode and is not putting out its rated current, but if you are going to repalce it anyway, may as well get 140+ amps.

My previous Class A DP had a Leece-Neville 180A alternator.

Thanks for the reply Gary.  Idle amps is one the things I have been studying closely while looking at alternators.  Larger case alternators like the Leese Neville have greater output at idle than the small case delco irregardless of maximum output . Unfortunately LM doesn't make a "spool" mount alternator above 130 max amps than will bolt up to a GM 454. I would have to fabricate a "J" mount.  I'm researching the larger case delco's to see if they will  have enough clearance  I have the 6 groove serpentine belt, from what I have read so far it should be able to handle the additional load.

Isaac-1

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Re: Alternator shopping, Looking for amperage advice
« Reply #8 on: October 14, 2018, 08:31:07 AM »
You might consider a slightly newer large case 145 amp or higher AD244 4 pin alternator, these were used up through about 2005 (then they switched to the 2 pin which must be connected to PCM to work in other than limp mode, do not buy the 06+ 2 pin version).  The AD244 should fit, though being a larger case you may need a longer serpentine belt depending on amount of slack as it moves the pulley out about 3/4 of an inch.

The AD244 uses a 4 pin CS130D where yours probably uses a CS130 connetor, they do make adapters like https://smile.amazon.com/Powermaster-160/dp/B000VVYKV8 or you can buy a CS130D pigtail for about $9 and splice it on.  The CS 130D is a weather proof rounded adapter which replaced the more square CS130 in about 2000 which did not have the weatherproof seal.

Ike

p.s. there is also the DR244G which is the cheaper (less rebuildable) version of the AD244 which may be worth considering.  These can be found on Amazon for under $100 like https://smile.amazon.com/DB-Electrical-ADR0290-Alternator-Silverado/dp/B007Y87Y2I/ which should fit, though output terminal may have to be reclocked if it does not line up right in your mounting bracket.

These newer large case alternators put out much more power at idle than your old 105 amp CS130 does.
« Last Edit: October 14, 2018, 08:33:06 AM by Isaac-1 »
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