240 vs 120 volt inverters

Re: 240 vs 120 volt inverters

bmet wrote: »

Thank you for statement about the Champion generator. I see those units at some of the national retail chains, and wondered why they are much cheaper.

Please don't misunderstand about the Champion generators. I think they're pretty good quality units. Just that they put an extra big sticker on them for marketing purposes. So if you realize when you buy one that a 3,000 watt generator is really a 2,400 watt generator, they're fine.

mike95490 wrote: »

Chris,
I appreciate the heck out of your detailed explanations about how this works. (and your stuff at the LEF & cogen forums )

No problem. Spent 19 years working with diesel generators - mostly ones with 12, 16 and 20 cylinders. But the principles are the same, just that the parts are smaller on the ones we use.

So, the 1700VA charger load is set by the % of Max Charger Capacity ?
And I could tweak that on the fly as the engine warms up?

Yessir. You can limit the charger with that setting, but the charger will be maxed out by either AC2 Breaker Size or Gen Support Amps, regardless of the percentage setting for the charger.

The Gen Suport amps is the most combined (loads & charging) for continuous load, but genset has to have enough "grunt" left to supply a 2 second surge load till the inverter goes into Assist Mode?

Yessir. The key word there being "continuous". It is not an absolute and the generator still has to be able to deliver surge. The Lister diesels (and clones) are pretty good on surge power. But they're a little slow on recovery time, coming back up to speed after being surge loaded. So you'll have to play with that a bit to surge load the generator to a level you (and your loads) are comfortable with.

If GenSupport = 9A it will "limit the charger load to about 1,700 VA"
and then Is that 2640w a 2 sec surge, or what the generator will have to carry steady ?
I've got some elevation here, and don't want to stress the Indian Iron to it's breaking point (which varies from fiberboard to aluminum)

The generator support amps is what the gen will be required to deliver continuous when in Gen Support Mode.

The Indian clone Listers (Listeroid) are not that bad. When you get one you have tear it all apart and get all the sand out of it or it'll be junk in two weeks. But they're pretty solid built (although the lube system could use a little improvement). So they're hard to break.

The 2100 / 2640 ratio is now the part I'm not following. What set that ratio ?

Basically, 2640 watts / 240 volts = 11 amps gen support setting. With just charger load, and very light other loads, the XW will run the charger at about 80% of that setting. You said you needed to work the Listeroid a little harder to keep it hot, so that 2100 watts is about 80 of the max loading when the charger is operating with light loads.

And the auto-transformer, I thought the GenSup+ added the inverter windings into load balancing, does the external auto-transformer help that significantly?

Well, there's some caveats with Gen Support Plus. It only works when the inverter goes into gen support. It will not help for loading with the charger at loads below the Gen Support setting. If you look in my photos earlier, at the last set where I was running a system load of ~5300 VA you'll see what Gen Support Plus does. Even the PSX-240 could not perfectly balance the loads on the inverter because I threw two big 120V loads on one leg that comes off a sub-panel in the basement. So where the PSX-240 is located it can't get access to the neutral current on the panel to balance it. But the Gen Supp + keeps the gen balanced regardless.
--
Chris