Automatic transfer switch

JJJJ

Aspiring apprentice
Hello. My apologies if this has already been asked. I have seen how an automatic transfer switch can move to the grid when batteries get low.

Could this also be used to activate a charger to charge the batteries when input from solar drops off (clouds, night, etc)? Or would something else be recommended?

Thanks in advance
 

Steve_S

Offgrid Cabineer, N.E. Ontario, Canada
Various Inverter/Chargers including some All in Ones have built-in ATS capabilities that are programmable to operate in different modes or "priorities". These are usually;
- Battery->Inverter->AC Output (house)
- Battery Charge <- Charger <- AC-Input Genset OR Grid AC -> Passthrough (to house)
Or even have it prioritized if Batt Lo, Use Grid, If No Grid, start Genset, Charge Batts & Passthrough.
Some may even be programmed with scheduling to use only Low Time of Use power rates for charging batteries.

There are systems that can handle 12V battery banks to 48V banks and even higher (but different rules come into play) and of course Cost is always a factor. The All-in-Ones like Solark, Growatt, MPP-Solar are quite popular and come with various options & power ratings. Comprehensive modular systems like those from Victron, Schneider and so on can also handle such things.

Not all equipment is the same, I have listed Value Gear to Tier-1 Products and the prices are considerably different. The features, functionality, programmability, and capacities, as well as expansion capabilities, vary greatly.

Lastly, there are "external" ATS (AutoTransfer Switch) available but they require a signal from an Inverter/Charger or AIO. Additionally, the systems noted above may have an AGS (Auto Generator Start) module, which sends a signal to an external GCSM (Generator Control Start Module) which in turn can start & stop a compatible generator.

If you look at the Samlex links in my Signature, you will see examples of the type of Inverter/Charger system I use.
Hope it helps, Good Luck
 

JJJJ

Aspiring apprentice
Really appreciate the excellent replies. Thank you very much. Perhaps this was already said above. Since I am new to this world I have much to learn. This crude diagram tries to present what I was trying to say. Perhaps you have already said it....

Solar -->> Charge controller [if current charge battery] -->> Battery
/
/
no current from charge controller->trigger battery charger off AC (turns off if solar restarts) --->>> Battery
 

JJJJ

Aspiring apprentice
Various Inverter/Chargers including some All in Ones have built-in ATS capabilities that are programmable to operate in different modes or "priorities". These are usually;
- Battery->Inverter->AC Output (house)
- Battery Charge <- Charger <- AC-Input Genset OR Grid AC -> Passthrough (to house)
Or even have it prioritized if Batt Lo, Use Grid, If No Grid, start Genset, Charge Batts & Passthrough.
Some may even be programmed with scheduling to use only Low Time of Use power rates for charging batteries.

There are systems that can handle 12V battery banks to 48V banks and even higher (but different rules come into play) and of course Cost is always a factor. The All-in-Ones like Solark, Growatt, MPP-Solar are quite popular and come with various options & power ratings. Comprehensive modular systems like those from Victron, Schneider and so on can also handle such things.

Not all equipment is the same, I have listed Value Gear to Tier-1 Products and the prices are considerably different. The features, functionality, programmability, and capacities, as well as expansion capabilities, vary greatly.

Lastly, there are "external" ATS (AutoTransfer Switch) available but they require a signal from an Inverter/Charger or AIO. Additionally, the systems noted above may have an AGS (Auto Generator Start) module, which sends a signal to an external GCSM (Generator Control Start Module) which in turn can start & stop a compatible generator.

If you look at the Samlex links in my Signature, you will see examples of the type of Inverter/Charger system I use.
Hope it helps, Good Luck
After a good night sleep and some fresh coffee, I went back and read the specs on your sheet. I found the following very interesting:
1614419567442.png
If I am reading this correctly, it sounds like this is what I may be looking for. Am I correct in understanding that this allows input from both the solar charger and the grid? And it sounds like input from both can be blended to charge the batteries? If so this would be ideal in cloudy conditions, night, etc. Am I also understanding correctly that this works with the BMS and will automatically activate the charger when the battery runs too low and switch to grid (and/or generator) power? Second cup of coffee starting to work. So the inverter runs off the batteries unless they shut down, and then reverts to grid or generator? Sorry if this was obvious. I am new to this idea and am in the planning stages of a system build. Thanks again for all help provided.
 

Steve_S

Offgrid Cabineer, N.E. Ontario, Canada
The Samlex can take a 50A input from a Solar Charge Controller which is limiting the size of battery assembly that change.
They (some models) can be connected to both Grid & Genset AC Input. ATS is built-in and can be programmed as to when to switch & come on.
They still need a GCSM to autostart & run a compatible genset, that is pretty much a universal thing.
Samlex is Tier-1 product and not cheap ! an EVO-4024 is about $2200 USD plus the RC-Remote.

I do not know of any system that works like you are thinking. The battery charge is what determines if batts are low or not. An SCC will charge when there is sun and will adapt to conditions per the battery state. Charging is triggered when batts are low and that can be programmed to use either Grid or Genset AC, or to make use of TOU rate shifting as some are doing now.

The AIO systems like SolarArk, Growatt, MPP-Solar have several advantages including easier installation and many can be stacked to increase capacity if needed. For the cost of one Samlex, you can get a pretty respectable AIO with SCC, Inverter/Charger built-in.
 

JJJJ

Aspiring apprentice
I see the appeal of your discussion.

The Victron MPPT I was looking at was about $325. The Samlux I checked out was a step below the one you mentioned at about $1300 for a rough ticket price of about $1625.

The MPP Solar LV 2424 Hybrid lists for $644.

Feature sets appear roughly equivalent. The concerns with the less expensive one is if one were planning on running motors (e.g. washing machines) due to rapidly cycling watt usage and peaks would stress the less expensive inverter and would compromise life span.

The more expensive unit appears to use roughly half to a third of the standby power consumption from rough estimates.

Gosh, the more I learn, the less I know.....
 
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