what does "idle power" mean in the inverter spec sheets?

[ljwobker]

So I found this: https://diysolarforum.com/threads/understanding-aio-idle-power-consumption.41017/
Which is somewhat close to what I'm asking but not quite... I see values for "idle power consumption" in the spec sheets of a lot of these inverters/AIO's ... but what isn't clear to me is which mode (modes?) of operation these idle values do and don't apply to.

If I have one of the AIO's that functions as an inverter/charger/transfer switch, and we assume that "normal" operations is with the AC mains connected, this means that the vast majority of the time the inverter isn't actually doing anything, right? It's just periodically checking the voltage on the battery side, and if that's below the threshold it clicks on the charger function, then clicks it off whenever the high threshold is reached... in the meantime, the AC mains power is just being passed through the transfer switch to the AC load side, right? So I would *think* that in this case the power consumption of the inverter itself when not topping up the batter would be VERY low (maybe just a couple of watts for the microcontroller?)

Do I have some part of that incorrect? I'm basically thinking of one of these AIO's as a big UPS, but I'm trying to figure out what the various vampire draws for the system would be. (In reality I'm just trying to learn how all this works... but this seems like a use case I can wrap my brain around...)

 

[Mattb4]

There is a lot more going on in a AIO than simply acting as a UPS. They incorporate SCC, Auto transfer switch, DC to AC inverter, AC to DC charging and also a CPU driven control unit.

In regards to what the spec sheet means when it says idle current. My assumption is this value is what you have in the way of minimum current draw when the AIO is doing nothing more than sitting there being energized (power save mode). If it is actually doing something than the current draw increases.

 

[Dynoman]

There is a lot more going on in a AIO than simply acting as a UPS. They incorporate SCC, Auto transfer switch, DC to AC inverter, AC to DC charging and also a CPU driven control unit.

In regards to what the spec sheet means when it says idle current. My assumption is this value is what you have in the way of minimum current draw when the AIO is doing nothing more than sitting there being energized (power save mode). If it is actually doing something than the current draw increases.

I agree the (idle power) is what the AIO or Inverter/Charger or Inverter consumes while turned on and not supplying any output power (all loads disconnected).

For some devices a (power saver mode) is different. The device will go into a ultra low power use mode while it scans for loads. If a load is present above a set threshold the unit goes out of power save mode and supplies the loads. My understanding this feature is not normally used because of the threshold level may not work well when a system is suppling small loads along with the the time lag of supplying loads power, but some may use it.

All the AIO specs I have reviewed have a fairly high (idle power) consumption.

 

[Mattb4]

I have done a small amount of testing using the power save mode on a spare AIO I got in yesterday. It is interesting watching it work. Output voltage from the inverter drops down to 1v and every 30 seconds it blips up to about 17v. When powering a restive load of a small 400w space heater it takes that time interval before the inverter wakes up and outputs the full 120v.

 

[ElectricIslander]

Sounds like what is known as "Search Mode" - stays in standby mode until a load is detected.

For inverters the "Idle mode" is the "tare" or self power consumption when the inverter is inverting, but there is next to no load (ie when search mode has been triggered by a small load.

Non-all in one systems also have an idle load beyond the published tare load that is the sometimes the considerable sum of all of the networking, charge controller, battery controller, inverter, autostart box etc. etc.