using 2 inverters, one ~300W , larger @ ~ 1000-2000 W

westbranch · May 2012

I have had the idea of being bi-inverted... :cool:
that is, using a ~300W inverter (MS300?) connected in tandem with a ~1000+W inverter in the new install.
will have 2 Distribution Centers, each handling one inverters output.

I have been looking into auto transfer switches for when the Generator is running vs manual,
and then realized that I could use an inverter with a built-in transfer switch... Voila, problem over... I think!

Is it logical and energy efficient to run a non-auto-transfer inverter [connected to the b-bank] alongside an auto-transfer inverter, when the generator is running and the battery is being charged?

In this case there is one inverter still being powered by the bank and the other being bypassed and the 110V loads now powered by the generator. Make sense?

BB. · May 2012

Re: using 2 inverters, one ~300W , larger @ ~ 1000-2000 W

Yes, it can make sense... Just make sure you are clear what you are doing with "neutral" (floating, ground referenced) and the inverters acceptable grounding (TSW vs MSW vs floating/grounding neutrals).

Because the inverters will not be synced... You will want to "home run" all neutrals back to the bus bars. You don't want to share a common neutral current path between inverters (unless the neutral can carry the maximum current from both circuits).

You can setup a manual transfer switch (or two breakers with lockouts--buy lockouts or even make your own out of sheet metal so only one breaker can be on at a time) so that you can easily use the generator if the inverter with the transfer switch fails for some reason.

-Bill

vtmaps · May 2012

Re: using 2 inverters, one ~300W , larger @ ~ 1000-2000 W

Westbranch, I'm curious why you want to do this. (I can think of several possible reasons). I'm shopping for a small inverter now. My reason is energy conservation. I want a small inverter to be on 24/7 with a low no-load draw. Most of my house is wired for the small inverter, and the vfx3524 will only provide power to 4 outlets in the house and will be turned on only when needed for laundry, power tools, etc. If the small inverter draws only 5 watts (versus 20 watts for the vfx3524) I stand to save about 330 wattHours per day. I am considering the Victron (24 volt input) 800 watt sine wave inverter whose no-load draw is 5 watts (2 watts in search mode). I could get by with 300 watts for the small inverter, but I haven't found a smaller inverter that draws less than the Victron. Too bad Morningstar 300 isn't available for a 24 volt system.

--vtMaps

westbranch · May 2012

Re: using 2 inverters, one ~300W , larger @ ~ 1000-2000 W

VT, jeez I hear an echo... yup, you and I are on the same page for saving amps via low consumption Inverters when in sleep/standby modes.

look at the data sheets here.
http://www.cotek.com.tw/product/55.html Auto transfer types
http://www.cotek.com.tw/product/54.html more like the Victron for surge
ps just noticed that the Transfer types do not post a standby load just no load draw while the non transfer does, however the NLD is lower on the ATS type

http://www.victronenergy.com/upload/documents/Datasheet%20-%20Phoenix%20Inverter%20180VA%20-%201200VA%20-%20rev%2003%20-%20EN.pdf
The 800's apparently now available.

BTW 'SteveK' uses a 24v 350w model, with an Exelteck 1000w for larger loads. Pleased as Punch with it...
http://forum.solar-electric.com/showthread.php?10123-Question-about-battery-charger-selection-with-EU2000-generator

So, I am looking for 2 TSW inverters

BB, I think I am going to have to do a sketch of what you have asked.. to follow after the weekend.

Bill, this has me really confused...
"You can setup a manual transfer switch (or two breakers with lockouts--buy lockouts or even make your own out of sheet metal so only one breaker can be on at a time) so that you can easily use the generator if the inverter with the transfer switch { fails} for some reason." ???

BB. · May 2012

Re: using 2 inverters, one ~300W , larger @ ~ 1000-2000 W

Sorry--Fails for some reason...

-Bill

westbranch · May 2012

Re: using 2 inverters, one ~300W , larger @ ~ 1000-2000 W

thought it was something like that, [quits, dies....] thanks for clarifying that Bill.

vtmaps · May 2012

Re: using 2 inverters, one ~300W , larger @ ~ 1000-2000 W

westbranch wrote: »

Bill, this has me really confused...
"You can setup a manual transfer switch (or two breakers with lockouts--buy lockouts or even make your own out of sheet metal so only one breaker can be on at a time) so that you can easily use the generator if the inverter with the transfer switch for some reason." ???

I think I know what he means. I have my vfx3524 on a midnite ePanel. The vfx3524 has a built in transfer switch. In the event that I need to remove (for repair) the vfx3524 the midnite Epanel has a bypass switch that routes the generator to the house rather than to the vfx3524. That bypass switch is two breakers, one upside down, with a metal 'lockout' that opens one while the other is closed. Midnite has their wiring diagrams online (pdf). Look how they wire the bypass switch.

--vtMaps

PhilS · May 2012

Re: using 2 inverters, one ~300W , larger @ ~ 1000-2000 W

westbranch wrote: »

Is it logical and energy efficient to run a non-auto-transfer inverter [connected to the b-bank] alongside an auto-transfer inverter, when the generator is running and the battery is being charged?

In this case there is one inverter still being powered by the bank and the other being bypassed and the 110V loads now powered by the generator. Make sense?

I run my home with three inverters... "water" (both well pump and pressure pump); "lights, entertainment and mini-split AC"; and "appliances".

When I run my generator, the "water" and "appliance" inverters charge the battery bank via their built-in transfer switches. "entertainment" continues to run off of the battery bank.

This system evolved over many years but I wouldn't design it any other way now. It works great. And no little "brownouts" on a TV or computer whenever a big load (like a well pump or a clothes dryer) starts. Also this way eliminates the momentary "switch" of power hitting TVs or computers when an inverter goes into charge mode.

Phil

2manytoyz · May 2012

Re: using 2 inverters, one ~300W , larger @ ~ 1000-2000 W

I ran multiple inverters with my last setup. The parasitic draw on a small system can eat your lunch.

My Xantrex Prosine inverter consumes an almost constant 16W when left on. In the Power Save mode, it only consumes 1.5W.

I built a few single circuit transfer switches that plugged into the appliance, the nearby outlet, and the inverter. When the grid was up, the appliance ran from the grid. When the grid went down, the appliance transferred to the inverter. Within 2 seconds, the inverter dectected the load, and powered up. The appliance would run on the inverter until the grid came back online, which would re-engage the transfer switches, moving the loads back to the grid. The inverter would detect no load, and go back into the power saving mode.

For lights, I ended up using a Vector 400W inverter, and a 12V keyless remote to turn the inverter on/off as needed.

The included relay is rated at 6A. I used a Bosch 40A type 12V relay to control the 12V power to the inverter.

[video=youtube_share;fwvCuZZCQ0o]

http://youtu.be/fwvCuZZCQ0o[/video]

When the inverter is OFF, it consumes nothing. The draw of the remote control circuit is almost nothing.

Inverter was $29. Wireless circuit is now $16 on Amazon. I buy my relays in bulk...

using 2 inverters, one ~300W , larger @ ~ 1000-2000 W

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