Schneider SW4048 generator input question

[hammick]

I have a Schneider SW4048 inverter. I have successfully used it as a charger with a 120v Yamaha inverter. It's max charging rate is 50% when only L1 input is used, so 20a max (maybe 15a I'm not sure).

I like the smaller inverters because they are quiet and easy on fuel. I was wondering if I hooked an additional 120v Yamaha inverter to the L2 input if the SW4048 would accept it and then give me full charging power. I realize L1 and L2 are usually 180 degrees out of phase but wondering if using two 120v inverters would work.

I'm guessing it probably won't work but don't want to try without knowing for sure for fear of frying my inverter. I'll call Schneider on Monday but wanted to see if anybody has done it.

[Sunking]

Simple. A big FAT NO.

At a minimum, the Inverter would immediately trip off line and open the circuit to the two generators. Most likely outcome is you let the Magic Smoke out of both Inverter and Generators never to make another sound again.

[Mike90250]

A simple step-up transformer is the best way to use a small inverter with a 240 inverter/charger Something in the 3-10KVa ballpark off fleabay should work.

[hammick]

A simple step-up transformer is the best way to use a small inverter with a 240 inverter/charger Something in the 3-10KVa ballpark off fleabay should work.

I'll look harder. The stuff I have seen on Ebay and Amazon is hard to figure out if it's for here or for Europe. I've seen the Outback unit but it's pretty pricey.

[Mike90250]

The outback PSX240 is pricey. Most modern transformers are rated 50/60 hz. A transformer is actually about the cheapest way to go, short of a larger generator or digging into the inverter to move transformer taps/jumpers around to convert it to 120V only.
Remember, a 480 - 240 VAC transformer will also provide 240 from 120 VAC (pure sine wave) Here's one, <$200 with free shipping:

http://www.ebay.com/itm/PowerTran-4-KVA-1-ph-Transformer-4KVA-440v-100-200-120-230v-SPOF-GH-4KBR-440-New-/401032012652?hash=item5d5f5ee36c:g:nNgAAOSwQItUIziT

DANG, I might get that myself, but I already have one.

[Sunking]

I am really uncomfortable getting into this because we have crossed a line that should not be crossed on a DIY forum telling folks how to use transformers. Since this is really small potatoes stuff where you can buy a transformer already wired up plug-n-play you can get a 3Kw Step-Up Step-Down transformer for less than $200 like this one.

[hammick]

Thanks for the responses guys. Mike I think I will buy one of those transformers. My main reason for wanting one is for backup in case my inverter fails. I would like to be able to power my place with my 120v inverters rather than have a 240v generator stuck in the corner that I have to exercise and maintain from time to time.

I'm assuming the transformer just mounts in an appropriate enclosure and wiring in and out is marked and pretty straight forward?

Now I need to educated myself on charging amps at 240v vs 120v.

I have two of the Yamaha Clone inverters generators that can be paralleled to double their power. The 120v outlet is 13.3 amps. So if I parallel them and run them through this transformer the amps at 240v stay the same (ignoring an losses through the transformer). Is it essentially 13.3 amps per leg or will using two of them through the transformer do noting to increase the charging power?

[hammick]

I am really uncomfortable getting into this because we have crossed a line that should not be crossed on a DIY forum telling folks how to use transformers. Since this is really small potatoes stuff where you can buy a transformer already wired up plug-n-play you can get a 3Kw Step-Up Step-Down transformer for less than $200 like this one.

Thanks Sunking. I'll look at that one and I absolve you and everyone else from any and all liability for any and all advice you have given me. Because of my profession I have seen a lot of death due to electrical accidents and I am very cautious.

I am doing my best to keep my place code compliant even though no inspections will take place.

[Sunking]

Thanks Sunking. I'll look at that one and I absolve you and everyone else from any and all liability for any and all advice you have given me. Because of my profession I have seen a lot of death due to electrical accidents and I am very cautious.

I am doing my best to keep my place code compliant even though no inspections will take place.

The reason I gave you that option is so you do not have to do any wiring. You aree not going to know what X, H, and O mean on a transformer.

[Sunking]

[QUOTE=hammick;n304689]Now I need to educated myself on charging amps at 240v vs 120v.[QUOTE]

That is easy. Forget line voltage. I have a 1500 watt battery charger that works from 110 to 290 VAC input. It will charge any battery type from 24 to 144 volts. So what is the charge current? I know the power already is 1500 watts. All I need to know is the battery voltage.

Power / Volts = Amps

24 volts @ 60 amps
48 volts @ 30 amps
96 volts @ 15 amps
144 volts @ 10 amps

[Mike90250]

The transformer I linked to has
No Thermal protection
No Overload protection
No physical protection (you have to put it in a Listed Enclosure to protect the terminals from your fingers)
and you have to wire it up PROPERLY. All this DIY stuff, if you don't want to pay the price to have someone else design and fab the gear, YOU have to learn how to properly and safely design and fab the gear. Shortcuts cause fires and shocks
You have to understand what 4KVA means, and what protection goes on the input and output (it's not likely a 2Kw genset will be able to overload a 4KVA transformer)

[hammick]

[QUOTE=Sunking;n304692][QUOTE=hammick;n304689]Now I need to educated myself on charging amps at 240v vs 120v.

That is easy. Forget line voltage. I have a 1500 watt battery charger that works from 110 to 290 VAC input. It will charge any battery type from 24 to 144 volts. So what is the charge current? I know the power already is 1500 watts. All I need to know is the battery voltage.

Power / Volts = Amps

24 volts @ 60 amps
48 volts @ 30 amps
96 volts @ 15 amps
144 volts @ 10 amps

Sunking my battery bank is 48v. My SW4048 inverter is rated at 45 max charging amps. So are you saying that using my two Yamaha inverter generators in parallel through the transformer you linked to will give me the max charge my SW4048 allows? 3000w/48v=62.5a

Or using just one of my inverter generators through the transformer will give me 33 charging amps? 1600w/48v=33.3a

If that is the case I have no need to use both in parallel for charging. I would only need both in parallel if my inverter failed or to run the AC on our travel trailer.

I have been dividing by AC voltage which is confusing me.

[hammick]

The transformer I linked to has
No Thermal protection
No Overload protection
No physical protection (you have to put it in a Listed Enclosure to protect the terminals from your fingers)
and you have to wire it up PROPERLY. All this DIY stuff, if you don't want to pay the price to have someone else design and fab the gear, YOU have to learn how to properly and safely design and fab the gear. Shortcuts cause fires and shocks
You have to understand what 4KVA means, and what protection goes on the input and output (it's not likely a 2Kw genset will be able to overload a 4KVA transformer)

Thanks Mike. The prewired box transformer Sunking has recommended looks to be a better and safer option for me. I have looked at them before but assumed they only output at 50hz for European devices.

[inetdog]

Thanks Mike. The prewired box transformer Sunking has recommended looks to be a better and safer option for me. I have looked at them before but assumed they only output at 50hz for European devices.

Essentially any transformer which is designed for 50Hz will work at 60Hz if the voltages are compatible.
The other way (60Hz transformer used on 50Hz) usually does not work and is not safe (unless used at less than the rated voltage.)
The output frequency of a transformer is always identical to the input frequency.
Not so for a UPS.

[Sunking]

[QUOTE=hammick;n304702][QUOTE=Sunking;n304692]

Now I need to educated myself on charging amps at 240v vs 120v.

Sunking my battery bank is 48v. My SW4048 inverter is rated at 45 max charging amps. So are you saying that using my two Yamaha inverter generators in parallel through the transformer you linked to will give me the max charge my SW4048 allows? 3000w/48v=62.5a.

No that is NOT what I am saying. You have a 45 amp battery charger at 48 amps. With 120 volts you will be limited to roughly 22 amps of max charge current assuming 1500 watt generator, and 45 amps with 240 volt 3000 watt input. Your AC input is 12 amps max. At 120 volts is 120 x 12 = 1440 watts, or 2880 watts @ 240 VAC. You cannot input 24 amps @ 120 volts to get 2880 watts.

No disrespect is intended but you are getting in way over your head. You do not understand the basic fundamentals and we cannot teach you what you need to know over a Forum. What it takes to get where you need to be is a 2 year technical degree and 5 years OJT is the minimum requirement to do this on your own. It is not something we can teach you here.

To use your 4048 is intended to be used in a home premises wiring system using 240/120 wiring. To do that really requires a minimum 3 Kva 240/120 generator just to run the battery charger. If you want to run both charger and supply power to your home while charging requires a larger generator. You are trying to cut corners to make the system do things it is not intended to do