Inverter With SUB function

[mrzed001]

no u haven't understood the question*

it isn't normal to draw 2 amps from grid, when there is enough solar energy for load and charger, and showing on inverter screen that it is drawing 0 amps from utility grid.

It is normal, because in this way it makes it sure not to BACKFEED to the grid.
Yes, it could. And in many places it is not allowed.
So it enables a little bit from utility to flow through ... just to be safe.

You can buy Online double conversion units from MPP Solar.
There the AC is converted to DC + DC from PV + DC from battery -> and a DC/AC inverter makes your own perfect sine wave.
There is no backfeed, because of the double conversion. But it costs you about 5% loss in the double conversion.

 

[timselectric]

it isn't normal to draw 2 amps from grid, when there is enough solar energy for load and charger, and showing on inverter screen that it is drawing 0 amps from utility grid.

Just think of it as AC idle consumption.
It's what is used to make the inverter work in SUB mode. It's not applied to the loads, therefore not registered on the screen. Same as the idle battery consumption isn't registered on the screen. The screen only shows what the loads are using.

 

[12VoltInstalls]

Just think of it as AC idle consumption.
It's what is used to make the inverter work in SUB mode. It's not applied to the loads, therefore not registered on the screen. Same as the idle battery consumption isn't registered on the screen. The screen only shows what the loads are using.

Is it really 2A? The 1012LV does 0.2A… until I turn the switch off

 

[timselectric]

I have personally measured 1.6a on mine.
I just consider it the cost of having the feature.
I don't use SUB mode, except for special circumstances. (Mostly just testing situations)

 

[abhelou]

Just think of it as AC idle consumption.
It's what is used to make the inverter work in SUB mode. It's not applied to the loads, therefore not registered on the screen. Same as the idle battery consumption isn't registered on the screen. The screen only shows what the loads are using.

AC idle consumption is not okay to be 2 amps, while this is the case. too much to pay for such feature. i'm sure this feature can be found on other inverter for less idle consumption. if anyone has experience with different solar inverter which has a fine SUB mode ?

 

[abhelou]

I have personally measured 1.6a on mine.
I just consider it the cost of having the feature.
I don't use SUB mode, except for special circumstances. (Mostly just testing situations)

while you don't use it, you can buy much cheaper inverters without this feature. SPF 5000 ES is famous because of the hybrid feature for blending utility and solar energy. disappointing growatt

 

[12VoltInstalls]

don't use SUB mode, except for special

Well December 2021 was the first time I had any grid backup. Last spring I was ‘back’ for the summer the first of April. It’s only been a couple days now since I turned the AC off. 46kWh grid used since February 5th. I have been running sbu but with the switch thrown it’s SB like it should be

 

[timselectric]

Well December 2021 was the first time I had any grid backup. Last spring I was ‘back’ for the summer the first of April. It’s only been a couple days now since I turned the AC off. 46kWh grid used since February 5th. I have been running sbu but with the switch thrown it’s SB like it should be

SBU is the mode I run in. But, if there's a big storm system coming. I'll switch to SUB, to save the batteries for the possible outage coming. As soon as the storm clears, I switch back to SBU.

while you don't use it, you can buy much cheaper inverters without this feature. SPF 5000 ES is famous because of the hybrid feature for blending utility and solar energy.

Part of the reason I chose this inverter was for this feature. Whether I use it or not, it's nice to have options.

 

[abhelou]

SBU is the mode I run in. But, if there's a big storm system coming. I'll switch to SUB, to save the batteries for the possible outage coming. As soon as the storm clears, I switch back to SBU.


Part of the reason I chose this inverter was for this feature. Whether I use it or not, it's nice to have options.

not an option anymore when it draws that much idle power. if you find it an option, i'm sure most of users wont see it as an option when it draws that much of power. you must be living somewhere where electricity is cheap

 

[timselectric]

not an option anymore when it draws that much idle power. if you find it an option, i'm sure most of users wont see it as an option when it draws that much of power. you must be living somewhere where electricity is cheap

Not too expensive.
$ 0.17 kwh
But, it's a rarely used option.
If I was planning on SUB being the primary function, I might think differently. But, I still think that it's cheaper than trying to add battery to a grid tied system.

 

[abhelou]

Not too expensive.
$ 0.17 kwh
But, it's a rarely used option.
If I was planning on SUB being the primary function, I might think differently. But, I still think that it's cheaper than trying to add battery to a grid tied system.

for people who need this feature as priority, it is a disappointment. it is a draw of around 300kwh per month. poor growatt

 

[TomC4306]

for people who need this feature as priority, it is a disappointment. it is a draw of around 300kwh per month. poor growatt

What?!

1 amp x 120 volts = 120 watts.
120 watts x 24 hours = 2880 watthours.
2880 watthours x 30 days = 86400 watthours.

Also known as 86.4 kWh. Per month.

My grid electric costs $0.10 per kWh.
So... This horrible, nasty standby consumption costs about $8 a month.

That's just the cost of using this particular inverter in this mode.

Thanks for bringing this to the attention of the community.

 

[timselectric]

It's a good mode for someone to get started on their system. Just add solar panels and you are already saving money. Then add batteries as the budget allows. I would never consider this mode as a permanent solution.
But, moving all but 2 amps to solar. For this inexpensive price. Is a big step in the right direction.
Everyone needs to find what works best for them. This was perfect for me.

 

[TomC4306]

a good mode for someone to get started on their system

Agreed

 

[12VoltInstalls]

That's just the cost of using this particular inverter in this mode.

Plus there’s the simple fact that any unit has idle power consumption when not connected to grid.
The ken’n’barbie-sized MPP 1012LV-MK has been metered as low as 24? watts and as high as 38W. (I’m unclear why that varies). My point is that’s the ‘cost’ of running the equipment- yes, the same way you view it. Except that the cost is not a monthly fee like the grid, it’s just the overhead needed to run the equipment that you need to plan for up front.
The cost of using the grid is in dollars and you can’t just turn that stuff off like you can your inverter.

FWIW the Reliable/QZRELB 2000W high frequency inverter I ran for a few weeks was 11W. If one is stressed out about idle consumption there’s an inexpensive way to avoid medication.

 

[abhelou]

It is normal, because in this way it makes it sure not to BACKFEED to the grid.
Yes, it could. And in many places it is not allowed.
So it enables a little bit from utility to flow through ... just to be safe.

You can buy Online double conversion units from MPP Solar.
There the AC is converted to DC + DC from PV + DC from battery -> and a DC/AC inverter makes your own perfect sine wave.
There is no backfeed, because of the double conversion. But it costs you about 5% loss in the double conversion.

poor design then, maybe they could have done it better as other manufacturer has done it. this inverter is supposed to reduce electricity bill

 

[12VoltInstalls]

this inverter is supposed to reduce electricity bill

No, it’s supposed to safely function as an AIO unit processing grid power and solar power. The savings come from appropriate use of the device.

 

[timselectric]

poor design then, maybe they could have done it better as other manufacturer has done it. this inverter is supposed to reduce electricity bill

It does reduce your electricity bill.
By the total amount, minus 2 amps.
Assuming that you are producing enough to cover all of it.

 

[timselectric]

If 2 amps is a high percentage of your total loads. Then, you need to be looking at a much smaller system that can be more efficient.

 

[mrzed001]

poor design then, maybe they could have done it better as other manufacturer has done it. this inverter is supposed to reduce electricity bill

The "well designed" Victron works in the same way :D



Also every inverter needs power to run itself.
Like your TV does. If you do not need it, shut it down

There is no "other manufacturer" who can do it with 0W self consumption