Dank Farrik
New Member
- Joined
- Feb 1, 2022
- Messages
- 155
Hi all, I've been contemplating between a build using either the Growatt 48V 3000TL LVM or the MPP Solar PIP 3048LV-MK. I have a few questions about the MPP Solar AIO:
Here's the product description on Watts247's website:
https://watts247.com/product/pip-3048lv-mk/
Manual:
https://watts247.com/manuals/mpp/PIP-LV-MK/PIP-LV-MK 1KW-3KW manual-20200611.pdf?x68852
1. How does "Bypass Mode" work exactly? In the manual, for Setting 10 (Operation Logic), it mentions this for the "Automatic" setting:
"If selected and utility is available, inverter will work in line mode. Once utility frequency is unstable, inverter will work in bypass mode if bypass function is not forbidden in program 23."
Later on in the manual shows this for Bypass Mode and Line Mode:
It looks like in Bypass Mode, inverter AC output is disabled, and the utility AC input is connected directly to the AC output, thus "bypassing" the AC/DC converter and the DC/AC converter. That makes sense. What does not make sense to me is why the manual says "Once utility frequency is UNSTABLE, inverter will work in bypass mode". Wouldn't that just be passing through unstable utility AC input directly to the AC output? Looking at the diagrams, it appears that in Bypass Mode, utility power is powering the output directly, and the inverter output is shut off. So it seems to me like the manual description should instead be "Once INVERTER output frequency is unstable, inverter will work in bypass mode". In other words, if the inverter is unable to produce stable power, and utility is available, then pass utility straight through to the AC output. Right??
2. The production description mentions "Zero Transfer Time":
"Featuring Zero Transfer time. In other words, when it switches from utility to Inverter in either direction, there is zero time delay. Basically, Even when charging via utility it is always powering your load via the inverter, filtering any Grid Noise or spikes to your load No interruption."
The Line Mode diagram above reinforces this description: The AC input from utility is not directly connected to the AC output as is in Bypass Mode. In Line Mode, utility AC goes through the AC/DC converter, then through the DC/AC converter, before finally connecting to the load.
So my question is: am I correct in saying that in Line Mode, the neutral line of the utility AC is not physically connected to the neutral line of the AC output?
3. This topology contrasts with the Growatt 48V 3000TL LVM.
Manual here:
https://watts247.com/manuals/gw/Growatt SPF 3000TL LVM Series User Manual.pdf?x68852
From Growatt's manual, it seems like if the utility AC is connected, it is always in "Bypass Mode" and is always directly connected to the AC output. In fact, you cannot disable this behavior at all, as long as the utility AC is connected:
This explains why the Growatt's Line Mode efficiency is rated at ">95%", and the MPP's Line Mode efficiency is rated at "92%". Where as utility power goes straight through for Growatt, for the MPP, utility power goes through A/D then D/A converters, thus reducing overall efficiency. On the flip side, for the same reasons, Growatt's transfer time is rated at 10-20ms, where as it's 0ms for the MPP.
Am I understanding this correctly?
Thanks in advance!
Here's the product description on Watts247's website:
https://watts247.com/product/pip-3048lv-mk/
Manual:
https://watts247.com/manuals/mpp/PIP-LV-MK/PIP-LV-MK 1KW-3KW manual-20200611.pdf?x68852
1. How does "Bypass Mode" work exactly? In the manual, for Setting 10 (Operation Logic), it mentions this for the "Automatic" setting:
"If selected and utility is available, inverter will work in line mode. Once utility frequency is unstable, inverter will work in bypass mode if bypass function is not forbidden in program 23."
Later on in the manual shows this for Bypass Mode and Line Mode:
It looks like in Bypass Mode, inverter AC output is disabled, and the utility AC input is connected directly to the AC output, thus "bypassing" the AC/DC converter and the DC/AC converter. That makes sense. What does not make sense to me is why the manual says "Once utility frequency is UNSTABLE, inverter will work in bypass mode". Wouldn't that just be passing through unstable utility AC input directly to the AC output? Looking at the diagrams, it appears that in Bypass Mode, utility power is powering the output directly, and the inverter output is shut off. So it seems to me like the manual description should instead be "Once INVERTER output frequency is unstable, inverter will work in bypass mode". In other words, if the inverter is unable to produce stable power, and utility is available, then pass utility straight through to the AC output. Right??
2. The production description mentions "Zero Transfer Time":
"Featuring Zero Transfer time. In other words, when it switches from utility to Inverter in either direction, there is zero time delay. Basically, Even when charging via utility it is always powering your load via the inverter, filtering any Grid Noise or spikes to your load No interruption."
The Line Mode diagram above reinforces this description: The AC input from utility is not directly connected to the AC output as is in Bypass Mode. In Line Mode, utility AC goes through the AC/DC converter, then through the DC/AC converter, before finally connecting to the load.
So my question is: am I correct in saying that in Line Mode, the neutral line of the utility AC is not physically connected to the neutral line of the AC output?
3. This topology contrasts with the Growatt 48V 3000TL LVM.
Manual here:
https://watts247.com/manuals/gw/Growatt SPF 3000TL LVM Series User Manual.pdf?x68852
From Growatt's manual, it seems like if the utility AC is connected, it is always in "Bypass Mode" and is always directly connected to the AC output. In fact, you cannot disable this behavior at all, as long as the utility AC is connected:
This explains why the Growatt's Line Mode efficiency is rated at ">95%", and the MPP's Line Mode efficiency is rated at "92%". Where as utility power goes straight through for Growatt, for the MPP, utility power goes through A/D then D/A converters, thus reducing overall efficiency. On the flip side, for the same reasons, Growatt's transfer time is rated at 10-20ms, where as it's 0ms for the MPP.
Am I understanding this correctly?
Thanks in advance!
