Turning on and off DC/AC Inverters

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I plan to have two 48V DC to AC Inverters (1 kW 120V) and (5kW 240V)

For better efficiency, especially in winter when there is not too much solar production,
I would like to turn the Inverters on only when needed.

I try finding inverters with remote control, but in the case of 48V Inverters,
there is not as much choice of Inverters than in the case of 12 V Inverters.

If I cannot find an Inverter with a remote control, I am considering putting in parallel
with the main switch a relay that I can control manually with a timer clock or other mechanism.

Is there any issue doing so, as I wonder why Inverters don’t always provide a remote control?

Note: I plan to use a delay timer to activate my transfer switch,
so the load will be applied only after having the Inverter been running.
 
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MichaelK

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I would NOT utilize any kind of remote. You need a transfer switch, or an either/or breaker to make use the outputs of the two inverters never meet. They MUST NEVER be wired in parallel to each other. If they do, they will not be phase-locked, resulting in massive distortion, and likely electrical damage.

The only way two inverters can be placed in parallel is if they are designed to be paralleled, and they are network connected so they can match phases. Usually that means two inverters of exactly the same model, with exactly the same firmware.
 

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@MichaelK Thank you for the feedback. Sorry I should I given more explanations.
The AC outputs load of the two inverters are independent and have their own transfer switch between the grid and the load.

The smaller inverter will be used at night to provide lighting, and the larger inverter
will be used only during the day when the battery is charged to use any surplus of energy.
- My question is what would be the recommended way to turn on and off an inverter when not in use?
Some inverters, in particular the 12 V ones, provide often a remote switch but this is not common for 48 V systems.
However, inverters have a power switch button, so can I just connect in parallel to this button a relay to this turn on the inverter?
Note: I plan adding a delay timer so the load will be connected to the inverter only after a certain time.

Any recommendation for 48V Inverters (1kW 120V) and (5kW 240V) with low idle consumption would be also very helpful.

 
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MichaelK

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- My question is what would be the recommended way to turn on and off an inverter when not in use?
Some inverters, in particular the 12 V ones, provide often a remote switch but this is not common for 48 V systems.
However, inverters have a power switch button, so can I just connect in parallel to this button a relay to this turn on the inverter?
Note: I plan adding a delay timer so the load will be connected to the inverter only after a certain time.

Any recommendation for 48V Inverters (1kW 120V) and (5kW 240V) with low idle consumption would be also very helpful.

Do you have any electric clocks that will loose their time with a power shutoff? That would include time on the kitchen stove, or other important loads like your computer router that you might not want switching on and off?

All the tier-1 brands have idle draws in the 20-30 something range. I posted them a few weeks ago, but going from memory I think...
Magnum: 25W
Outback: 34W
Schneider:29W

Of course though memory loss runs in my family.

Any of these inverters would be an excellent choice. Is what you are wanting split-phase 120/240VAC, or 230VAC? The first line of your first post suggests split-phase to me? Both the Magnum and Schneider are native 120/240. The Outback can also make 120/240, but you need two units.
 

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Do you have any electric clocks that will loose their time with a power shutoff? That would include time on the kitchen stove, or other important loads like your computer router that you might not want switching on and off?
1. The small inverter (48V DC - 120 V AC 1kW) will be used only to power lights in a building at night,
- so can be shut down during the day.​

2. The larger inverter (48V DC - 240 V AC 5kW) will be used only to power a water heat pump,
running basically like a fridge, like for 5 minutes every 10 minutes,​
and will be used only during the day when the battery is charged to use any surplus of energy,​
- so can be turned off otherwise.​

All the tier-1 brands have idle draws in the 20-30 something range. I posted them a few weeks ago, but going from memory I think...

Magnum: 25W
Outback: 34W
Schneider:29W
I think I found your posting:


I noticed that all the devices from your list are Inverter/Chargers but I only need the Inverter function.

The solar system that I am desiging is not an AIO, the SCC and the DC to AC inverters are all independent devices.

The SCC is not connected to the grid or used to power back the grid.

Any of these inverters would be an excellent choice. Is what you are wanting split-phase 120/240VAC, or 230VAC? The first line of your first post suggests split-phase to me? Both the Magnum and Schneider are native 120/240. The Outback can also make 120/240, but you need two units.
Yes, I am looking for a split-phase to run a water heat pump.
But I cannot find good information about the specific in-rush current power consumption.

Note: From your list, none of the inverter provide a remote control. I wonder how to add safely this capablity?
 
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MichaelK

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I noticed that all the devices from your list are Inverter/Chargers but I only need the Inverter function.

Yes, I am looking for a split-phase to run a water heat pump.
But I cannot find good information about the specific in-rush current power consumption.

Note: From your list, none of the inverter provide a remote control. I wonder how to add safely this capablity?
I'm not an electrical engineer, but what I've been told is that the charger function is built in as an added feature, because it just adds a bit to the overall circuitry already present for the inversion. It comes in handy in the dead of winter (maybe you don't have one?) if there's a week of cloudy weather.

Inrush is something that may are may not be documented, but this is something you can determine yourself with the proper tools. I have measured the inrush of my pump with this Uni-T 216C meter. I also have a much more expensive Fluke inrush meter, but the less expensive meter agrees with the Fluke to 1% accuracy.

Here is a pump chart posted by another member Mike94590, that closely approximately what I determined with my own pump. This may be a help to you.
1654620818103.png
 
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