Your engine might be rated at what we used to call 'Sears Horsepower' where their compressors had 4HP rated motors for 115VAC 15A circuit which isn't possible of course. They'd rate the max surge current for a few milliseconds I think.
Anyway, your alternator is rated at 2200 RPM for max current. Without knowing your engine RPM it's hard to compare but 1:2 is likely too high for this alternator. And if you slow down the engine to 1100 RPM to create 2200 RPM you won't get the rated power. I'd go the other direction with 2:1 or even 3:1 depending on what max engine RPM is. The systems I've designed that used a 10KW ONAN genset created 110VAC into an 80A charger. And even then I could control the charger to limit charge current which in turn limited load on the generator. You will find even with sealed lead acid batteries that the max current will only be there for a very short time so trying to achieve that level of power output for charging is likely not needed. Lithiums are a different story. John > -----Original Message----- > From: fxkl47BF via Emc-users [mailto:emc-users@lists.sourceforge.net] > Sent: June-27-21 7:21 AM > To: Enhanced Machine Controller \(EMC\) > Cc: fxkl47BF > Subject: Re: [Emc-users] OT: power, horsepower, and a bad brain > > ------- Original Message ------- > > On Sunday, June 27th, 2021 at 8:07 AM, fxkl47BF <fxkl4...@protonmail.com> > wrote: > > > ------- Original Message ------- > > > > On Sunday, June 27th, 2021 at 7:19 AM, andy pugh bodge...@gmail.com wrote: > > > > > On Sun, 27 Jun 2021 at 12:44, fxkl47BF via Emc-users > > > > > > emc-users@lists.sourceforge.net wrote: > > > > > > > all of my feeble calculations led me to believe that a 6.5 hp gasoline > > > > engine was more than enough to power a 220 amp 12 volt > alternator. either my 6.5 hp engine is more feeble than my brain or my > calculations are way off. > > > > > > > > 220A x 12V = 2.640kW = 3.5hp. So it should be able to manage it. > > > > > > > > You might need to look at the pulley ratios. Do you have a performance > > > > > > > > curve for the engine and the alternator? You need to consider the > > > > > > > > relative torques for your chosen speed. > > i have about a 2:1 increase belt drive > i was running the engine at full speed > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
