Skip to main content ↑ ↓
Topic: alternator (Read 906 times) previous topic - next topic

alternator

Need some advice from those that have upgraded their alternator. Wired my fwd ac with micro air soft start into inverter subpanel so I can run it down the road using combo solar and alternator power to keep it going. It does work, but appears 160 amp alt. will not keep up and even with 1000+ watts solar, batteries deplete fairly quickly and inverter goes to shutdown at 11.8 volts. Need a plug and play alternator that will handle the load, thinking probably 250 amps or more.

Re: alternator

Reply #1 –
May be cheaper off just running the generator,the bigger alternator may use more fuel then the generator or close to it.

Re: alternator

Reply #3 –
What inverter?  I have installed 110v alternators long long ago.  4400 watt and 5500 watt if memory serves me.

Propane gens only with 50 hour max run time was the issue

Are you sure no diodes are bad.  My LN had one bad out of 6

Re: alternator

Reply #4 –
I used a DelcoRemy 40si 240 amp alternator. There are bigger ones as well, the J180 long hinge mount on mine was a direct and easy swap.  You need a sense wire, plus and minus cables. No excite wire needed.  A 275 amp DR will cost around $1000.

When you boost alternator output you will probably need to increase cable size.  I have two 3/0 + and - cables (original) and two 4/0 + and - cables (added) running front to rear.

Alternators by Model Family | Delco Remy

You have to push a lot of amps into batteries and suck it out into an inverter to make 120v to run an AC.  Not quite as easy as it sounds.

Re: alternator

Reply #5 –
Thanks all. Not a real practical mod., but I live in hurricane country and would like a backup to gen and solar, if generator stops working. Do realize will need some wiring  and combiner upgrades.
Inverter is prosine 2500 and handles load well until voltage begins to fall. The 40 si appears to be able to supply 160 amps at engine idle, and supplemented with 50 amps or so from solar when possible, should overcome any inefficiencies in the inverter, so would hopefully break even on battery draw on a sunny day.
I do run the generator when I need to supplement the dash ac with roof airs, so this is more a redundancy and prepper kind of thing, 
The ac is wired to 20 amp plug and I have two 20 amp receptacles[ one from main panel, and one from inverter sub panel], so unit is normally plugged into main panel supplied by gen/sp.

Re: alternator

Reply #6 –
We live in hurricane area also,not much sun for solar during a hurricane,150 gallons of diesel will go a long way.Check out the
natural gas house generators if you have gas the gas usually stays on during a hurricane.

Re: alternator

Reply #7 –
Quote from: John44 –
We live in hurricane area also,not much sun for solar during a hurricane,150 gallons of diesel will go a long way.Check out the
natural gas house generators if you have gas the gas usually stays on during a hurricane.
Normally you are probably correct. I was on Galveston Island during Hurricane Ike in 08. Within hours of the hurricane hitting the coast, all electricity and natural gas was cut off to the island . Too many broken gas lines and downed power lines.  Luckily I had my bus conversion with a 10 kw diesel genset on high ground. After the water receded, brought it back and supplied my neighbors for 3 weeks, [6 hrs a day], till power and gas was turned back on. Ended up with six 100 ft extension cords. but did burn well over 100 gal of fuel.
 

Re: alternator

Reply #8 –
Harvey took out the gas in Port Aransas as well.  Now dealing with saltwater intrusion into gas lines during the storm.