But as the picture of the IQ8+ shows max 290W AC continuous (as @Solar Guppy) noted, then you're not going to get more than that out of it.
So at 290W max, you'll only get 75% of what the panel is capable of.
Solved: Limited IQ8+ inverter output - JA Solar panels rated for 395 Watts putting out 250 watts (63% of max rated)
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So at 290W max, you'll only get 75% of what the panel is capable of.
OPTIMALSOLAR
New Member
Ya, what is compatible and what is matched properly is a silly wide margin.
fromport
Solar Addict
I actually have a different version of the same datasheet:
Link is from my personal website:
Version number (bottom of first page) says:
IQ8SP-DS-0002-01-EN-US-2022-03-17
That data sheet shows:
Max DC current (2) [module Isc] A 15
(2) Maximum continuous input DC current is 10.6A
The version you linked of the same named PDF shows at the bottom:
IQ8SP-12A-DSH-00207-2.0-EN-US-2023-10-13 <- that is a more recent version.
Maximum input DC short-circuit current: 25A
Maximum module Isc: 20A
Maximum continuous input DC current : 12 A
This is all very confusing.
Let me see if I can get a sane answer from Enphase support.
Will followup
fromport
Solar Addict
As you know STC conditions are hardly met. I over panel inverter ratings with up to 125% DC -> AC rating to take into consideration.
fromport
Solar Addict
Answer from Enphase:
Both of those 2 spec sheets both mention 12 Amp continuous input.
I think Enphase is very very confusing at this point.
I have the older IQ8+, so am I limited to the 10.6 amps ?
I think I will have to hook one up to a variable power supply and find out the hard way.
Hedges
I See Electromagnetic Fields!
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fromport
Solar Addict
Why do you think it has to do with firmware upgrade ?
???
I don't get the question
Hedges
I See Electromagnetic Fields!
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Same model number, higher current handling now. Is that because hardware was upgraded without a model number change?
Or because they programmed a lower limit in the past, changed the firmware later maybe to make it more marketable?
Which would mean now we know that Enphase was shipped configured for less than full output capability.
Or because they programmed a lower limit in the past, changed the firmware later maybe to make it more marketable?
Which would mean now we know that Enphase was shipped configured for less than full output capability.
fromport
Solar Addict
I copied you the response that there are 2 different models:
IQ8PLUS-72-2-US
&
IQ8PLUS-72-M-US
They did not give me any more information than that.
I don't know anything about soft/hardware differences.
The fact that the old spec sheet said 10.6 amps and the latest greatest 12 _might_ implicate that a software update might be able to improve the Imp of the inverters.
But your guess is as good as mine.
Maybe ask them ?
400bird
Solar Wizard
But the set up flat lined at 250 watts per panel.
I can't get to a combo of the listed possible specs that add up to 250 watts.
fromport
Solar Addict
Max power of a panel at STC specs = 25C ambient temp and 1000 watt/sq m2 lumination.
Today is solstice so the lowest the sun will be in the northern hemisphere.
So whatever the Vmp under these conditions, times what ever the max amps from the panels the IQ8 will accept seems to be 250 watt.
Even if the panel was able to provide more amps, the max voltage of the panel (only 54 cells) and the max amps of the input of the IQ8+ sets the max limit of power converted hence the flat line.
Last edited:
Can't you just look at the back of your specific micro-inverter; like the pic shared earlier on this thread...
400bird
Solar Wizard
The lower insolation/sun exposure, whatever happens in winter, gives a lower overall curve. It does not present as a clipped flat line from 10:30-2:30.
Voltage increases when it's cold (the first post says 30f mid day), so VMP will be at least 30.84
250 watts / 30.84 volts= 8.1 amps (well under either of the specs listed in this thread)
With cold weather voltage increase, the amperage is even lower at 250 watts.
Even at 32 volts, the amperage to hit 250 watts is 7.8
fromport
Solar Addict
You were/are trying to find the 250 watt value.
I was just pointing out that everything is lower because of time of year.
Fundamentally 54cell panels are a poor match for Enphase. Stick with 60 or 72 and you won't have an issue.
You also don't need an envoy to reprogram to achieve full output. The default grid profile is perfectly capable of producing name plate wattage. Now you do require an envoy to clear errors that pop up from time to time. I had to purchase one to reset 5 micros that had stopped functioning.
In my opinion this is a confluence of poor matching panel to microinver, shading, poor mounting, and poor time of year.
You also don't need an envoy to reprogram to achieve full output. The default grid profile is perfectly capable of producing name plate wattage. Now you do require an envoy to clear errors that pop up from time to time. I had to purchase one to reset 5 micros that had stopped functioning.
In my opinion this is a confluence of poor matching panel to microinver, shading, poor mounting, and poor time of year.
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