I have a WFCO Ultra III (WF-8955) converter that requires 950W of input. I'm surprised it takes that much power to run, but maybe I'm missing something. Apparantly a 1000W generator won't provide enough power, which makes sense, because they're rated 900W. I have a Yamaha 2000W generator, but I like the idea of using a 1000W generator, because they're nearly 20 pounds lighter, less DBA and run longer on a tank.I understand the converter can be switched out for one that requires less power. What's your recommendation, and what would you expect to pay someone to switch it out? What's the downside of a smaller converter? I'm a DIY type, but when it comes to power I run the other way. Thank you.

ZZSPIRAL1 wrote:What's the downside of a smaller converter? .Longer charge times.

The converter has a power factor of about 0.7, so that 950w input will pull about 1357VA from the gen continuous. That is nearly the continuous rating of the "2000w" gen.If you get a small enough (low amp instead of 55amp) charger to run on the "1000w" gen, the amps will be so low it will take forever to charge the battery bank.IMO don't even think about getting a 1000w gen for running a battery charger. It will have to run so long to get the batteries up, you might as well just stay on the gen all day and not run the batteries down in the first place :)

BFL13 wrote:The converter has a power factor of about 0.7, so that 950w input will pull about 1357VA from the gen continuous. That is nearly the continuous rating of the "2000w" gen.If you get a small enough (low amp instead of 55amp) charger to run on the "1000w" gen, the amps will be so low it will take forever to charge the battery bank.IMO don't even think about getting a 1000w gen for running a battery charger. It will have to run so long to get the batteries up, you might as well just stay on the gen all day and not run the batteries down in the first place :)I was thinking about adding a 100 W solar panel.

A 100w panel will do maybe 6amps mid-day, less earlier and later. 6 amps is two double lamps worth of Rv use--ie not a whole lot. It will certainly help (when the sun is out and you are in the open), but it is not a game changer between a 1000w and a 2000w gen IMO.If you have a mix of gen/charger and solar, the idea is to do a fast charge with the gen in the morning and let the solar do the rest all day at its low amps before you hit the batts from supper through movies till bedtime and maybe some furnace at night.That means the 2000w gen and a high amp charger for the short time gen part. It makes no sense to have a long low amp gen run and then a short period of solar at even lower amps.

BFL13 wrote:A 100w panel will do maybe 6amps mid-day, less earlier and later. 6 amps is two double lamps worth of Rv use--ie not a whole lot. It will certainly help (when the sun is out and you are in the open), but it is not a game changer between a 1000w and a 2000w gen IMO.If you have a mix of gen/charger and solar, the idea is to do a fast charge with the gen in the morning and let the solar do the rest all day at its low amps before you hit the batts from supper through movies till bedtime and maybe some furnace at night.That means the 2000w gen and a high amp charger for the short time gen part. It makes no sense to have a long low amp gen run and then a short period of solar at even lower amps.Okay, thank you.

Converters and generators | Good Sam Community

BFL13
Explorer II
Nov 03, 2013
The older PM3s, still for sale, do not go into boost every time, but act more like a WFCO, needed a low battery first. The PM4s have that different, act more like an Iota.

The 75 ampers and on up have PF correction in all versions so that they can still use a 15a circuit. It also helps with reducing gen VA amount compared with same amp, non PF corrected.

This website is complicated, but to get the info, you need to check the pdf part of each section

http://powermaxconverters.com/
pnichols
Explorer II
Nov 04, 2013
OK ... I give up.

I'm usually pretty good at hacking around on the Internet, but this time I guess I didn't have enough cups of java: Where are you guys reading on the PowerMax link above that some of their units have PFC??

What I did notice however, is that the 55 amp PM3-55-MBA model, with it's maximum continuous power of 780 watts at >85% efficiency, just might be able to be fully powered from a little Honda 1000i generator. Wouldn't that be a sweet combination -> a 55 amp multi-stage charger being powered via the smallest Honda inverter generator!
BFL13
Explorer II
Nov 04, 2013
Phil here ya go--where it says power factor converter :)

http://powermaxconverters.com/pm412volt.html

If the non PF corrected are like others at 0.7 PF then that 780 would be an 1,114VA draw

Note Randy has his own versions like a 60 where he says no more 55s. It is very confusing! IMO ask many pointy questions about exact features from where you buy.

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