PIP-4048MS and PIP-5048MS inverters

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Post by coulomb » Thu, 29 Dec 2016, 15:48

lopez wrote: Just wanted to know how much power the PIP4048MS draws from the grid?

Worst case, it could be bypassing 40 A and utility charging 60 A @ 55 V with 220 V utility, so that's 40 + 15 = 55 A. I think it's safe to say that this combination is unusual, so 6 mm^2 cable via a 40 A breaker should be sufficient.
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Post by lopez » Thu, 29 Dec 2016, 18:17

Sorry Coulomb, I meant under no load. How much power it would draw from the grid without the bypass being active.
Last edited by lopez on Thu, 29 Dec 2016, 07:46, edited 1 time in total.
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Post by lopez » Thu, 29 Dec 2016, 19:15

coulomb wrote: As Weber has noted. the essential difference is that LiFePO₄ has the very flat voltage versus SOC curve, and practically every other chemistry has a wider variation of voltage with SOC.


By data logging I created a graph (using Excel) of SoC vs volts for a 48V, 5.6kwh Li-NCM battery pack using 18650 cells. The curve is very linear and an accurate SoC can be attained simply by reading the battery volts. Unlike Lifepo4.

Li-NCM 18650 cells GRAPH - SoC vs volts
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Post by coulomb » Thu, 29 Dec 2016, 19:25

lopez wrote: I meant under no load. How much power it would draw from the grid without the bypass being active.

I would assume zero, while there was enough PV to cover the loads and ~50 W of losses. Otherwise, the ~50 W of losses. But I'm not sure about the priority. The processor and control electronics have diodes to allow power from the battery or utility. PV power always goes to the battery, so as long as there is 50 W of PV power, it will supply the losses. Which one of utility or batter takes the load when there is no PV depends on the relative voltages.

[ Edit: but if utility charging, it could of course go up to 60 A x 60 V + losses, perhaps 3700 W. ]
Last edited by coulomb on Thu, 29 Dec 2016, 08:34, edited 1 time in total.
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Post by rinaldoparaipan » Fri, 30 Dec 2016, 03:08

Have you got 72.70 firmware to upgrade?

Not yet, I'll send a mail to MPP Solar

[ Edited Coulomb: repaired formatting ]
Last edited by coulomb on Fri, 30 Dec 2016, 02:34, edited 1 time in total.

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Post by KG666 » Sun, 01 Jan 2017, 05:30

hoi,

i'am new here (from belgium , new to off-grid) and have read almost the 60pages, what is intressting is the acid new firmware.. but i have a problem (i think)

my inverter (pip4048MSD , mppsolar):
Image
my inverter is from 2016-04


i think this is my firmware (yes?):
Image

why are you all talking about 72.40 or .60 or 70? do i have 75.10??

i'am confused

someone has a changelog of this one?
save to go back to coulomb firmware?

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Post by coulomb » Sun, 01 Jan 2017, 14:58

KG666 wrote: i'am new here (from belgium , new to off-grid)
Hi and welcome.
and have read almost the 60pages
Well done.
my inverter is from 2016-04

i think this is my firmware (yes?):
Yes, you have firmware version 75.10.
why are you all talking about 72.40 or .60 or 70? do i have 75.10??
Interesting. Well, most of us have the single MPPT models. Yours is a Dual MPPT model (PIP-4048 MSD), with the 120 A of solar charging (ours are 60 A, and I think models from a few years ago had less than that). There were a few changes in 72.60 that accommodated the multiple MPPT models (there is also a triple MPPT version, and they seem to be making provision for future models as well).

I have to admit I was surprised that there weren't more changes to handle the multiple MPPTs. Now it looks like models that actually have the multiple MPPTs come with a different firmware than the single MPPT models. Now that this is mentioned, perhaps SolaMahn or another user has mentioned this already.

This brings up an important point. With the patched firmware (both types), we have demonstrated a fix one major problem (the inability to charge properly) and several minor ones (many thresholds are not lithium suitable). The fact that many people are using or asking about this firmware indicates that there is a genuine need, it's not just a few isolated users having a problem due to some unusual environment or other detail. We can't keep patching more and more versions, and we're at the mercy of the manufacturer for supplying the raw materials that we need to generate the patch.

So I think it's time to get the manufacturer to incorporate the main fixes into the official firmware. Others have demonstrated that the manufacturer is willing to listen to users' needs and incorporate them into new firmware, so it's a matter of setting up communications with them to make this happen.
someone has a changelog of this one?
I've never seen a change log of the firmware. It would be good to have, and most software (firmware is software that is stored in hardware, so it's still software) have change logs.
save to go back to coulomb firmware?

No, it's almost certainly not safe to use a 72.XX based firmware (patched or not) in a machine that comes with 75.XX firmware. The first two digits are the major version numbers, which when changed usually indicates a major change with some compatibility loss. At minimum, I'd expect that you would not be able to see the two MPPTs' icons on the LCD screen. It's possible that they have a completely different LCD display, so the screen may make no sense at all.

Plus, until the manufacturer releases the 75.10 update files, it won't be possible to go back to the original software, in case there is any sort of problem. For whatever reason, it's getting harder to find these software update files.
Last edited by coulomb on Tue, 03 Jan 2017, 04:22, edited 1 time in total.
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Post by KG666 » Sun, 01 Jan 2017, 18:10

okidokie coulomb, thats as clear as it can be ;)
thanks for the post! i will not try to "downgrade" to yours, hope that the "acid bug" is not for my version...

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Post by solamahn » Mon, 02 Jan 2017, 15:48

4048mst that i installed at Inauaia village in Mekeo uses 75 00 for U1 and 01 01 for U2 - U4 for a 12/15 manufacture date. Works really good
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Post by Solar Junky » Tue, 03 Jan 2017, 11:58

Happy new year to all!!!!!!

Found one of my comm boards is bad on my older unit, so have not been able to do the firmware update...

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Post by KG666 » Mon, 09 Jan 2017, 01:53

hoi,

I have an other question,

what would be beter for the pip4048MSD?

you can have 145v VOC and 60A max input current, so

2 panels in serial and than 4 parallel? (130v / 26A)
or all in parallel?

every panel is VOC : 65v and 6.58A Isc (333wp) (8 panels on one string, i have 2 string inputs and so i have 16 panels of 333wp)

i want to have the max to load my 840ah acid battery

grtz kristof

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Post by coulomb » Mon, 09 Jan 2017, 03:28

KG666 wrote: every panel is VOC : 65v and 6.58A Isc (333wp)

You have not stated what the Vmpp voltage or Impp current is. I'll guess the Impp at 6.0 A; in that case the Vmpp is 333/6 = 55.5 V. This is less than the battery voltage at the end of bulk charging. You need at least 1 V more than the battery voltage from the panels. So you'll definitely need at least 2S (two panels in series for each string).

Hopefully your panels when cold (I imagine Belgium gets pretty cold) won't have a combined Voc over 145 V. But you definitely can't go 3S at any temperature.

So your only option is 2S, so 2S4P for each MPPT.

[ Edit: Vmppt -> Vmpp . ]
Last edited by coulomb on Mon, 09 Jan 2017, 04:30, edited 1 time in total.
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Post by KG666 » Mon, 09 Jan 2017, 05:47

coulomb wrote:
KG666 wrote: every panel is VOC : 65v and 6.58A Isc (333wp)

You have not stated what the Vmppt voltage or Imppt current is. I'll guess the Imppt at 6.0 A; in that case the Vmppt is 333/6 = 55.5 V. This is less than the battery voltage at the end of bulk charging. You need at least 1 V more than the battery voltage from the panels. So you'll definitely need at least 2S (two panels in series for each string).

Hopefully your panels when cold (I imagine Belgium gets pretty cold) won't have a combined Voc over 145 V. But you definitely can't go 3S at any temperature.

So your only option is 2S, so 2S4P for each MPPT.



Indeed the Vmp = 54.7 and the Imp = 6.09 (some more, there are panels of 335wp in the pack)

i didnt think that way you did with the 333/6=55.5v , i took the 64.9v

the 2S4P was my first thought... so i will take that one Image



Image

grtz

edit :
an acid battery can go to 80% of the soc (20%left)
but is that via "ah" or via the voltage?

like my battery is 48v ,840ah
Last edited by KG666 on Mon, 09 Jan 2017, 00:47, edited 1 time in total.

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Post by coulomb » Mon, 09 Jan 2017, 15:28

KG666 wrote: an acid battery can go to 80% of the soc (20%left)
but is that via "ah" or via the voltage?
SOC (State Of Charge) is a measure of remaining energy, which is best measured in Ah (Amp.hours). Lead acid has a thing called the Peukert effect, whereby if you take out the energy quickly, you'll have less overall energy. However, assuming a suitably large battery (840 Ah is getting there), you can largely ignore this effect. Especially as you normally go nowhere near emptying the theoretical capacity of the battery.
like my battery is 48v ,840ah

My understanding is that for maximum life, you should aim for no more than about 20% (some say lower) Depth Of Discharge (DOD), so that's 80% SOC or 80% remaining. So with your 840 Ah nominal battery, you should be aiming to use only about 20% of that, or 168 Ah. At an average voltage of say 50 V when discharging, that's some 8.4 kWh.

This is one of the reasons that Lithium based batteries can be worth the extra money. While they cost more per nominal kWh, the fact that you can use say 80% of that nominal capacity, compared to 20% for lead acid, makes them attractive. In addition, they may last longer, though some of the lead acid batteries are capable of lasting 10 years as well.

Edit: I meant to add that battery voltage can be used as a crude measure of SOC for most chemistries other than LiFePO₄. However, you have to wait hours with no charge and no load for the measurement to be reasonably accurate, and this never happens on a real-life energy system. The PIP-4048 has such a crude SOC measurement. It's very rough for lead-acid batteries, and simply irrelevant for LiFePO₄ batteries. It may be more useful for non-LiFePO₄ lithium based batteries, but the scale is likely not correct (so you'd have to have a "translation table", and there may be areas near full or empty that are far less accurate).
Last edited by coulomb on Tue, 11 Apr 2017, 16:00, edited 1 time in total.
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Post by Northland » Mon, 09 Jan 2017, 16:36

The main benefit of Lithium, is that it's charge efficiency is much higher. This means less solar panels required, less racking for them, less charge controllers etc. Or, it means a faster recharge, giving a fully charged bank at 5pm on a rainy day, compared to a half recovery in lead acid

See this post where I crunch the numbers
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Post by KG666 » Tue, 10 Jan 2017, 03:26

What is the meaning of "Back to Battery" on the pip4048 ?

for now there are no solarpanels connected to my installation, so it runs on battery power till "it's out" and than it reloads on gridpower ... till 55v (back to battery), with 60A ( i know it's stupid*, but thats the way till i have installed all my panels Image )

so , it reloads the battery to 55v and than it stops , can or may i put that higher, say 57v (bulk is 57,4v, float is 55v)
or is this function only when there is not enought solar-energie to load the battery and beter left alone?

*this is a test run on my koi-pond


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Post by coulomb » Tue, 10 Jan 2017, 04:25

KG666 wrote: What is the meaning of "Back to Battery" on the pip4048 ?
When you are charging from the AC input, setting 13 tells the PIP when to go back to battery mode (i.e. the battery is providing power for the loads). Parameter 12 is the partner parameter; it sets when to start charging from the AC input, i.e. what the battery voltage has to fall to to trigger AC charging.
so , it reloads the battery to 55v and than it stops , can or may i put that higher, say 57v (bulk is 57,4v, float is 55v)
or is this function only when there is not enough solar-energie to load the battery and beter left alone?

Yes, you can set it higher or lower; that's what setting 13 is about. It has the title 'Setting voltage point back to battery mode when selecting “SBU priority” or “Solar first” in program 01' in the manual. Actually, the default value for this setting is 54 V, but the PIP often seems to overshoot by a volt or so. It needs to see at least the indicated voltage for a certain time, by which time the battery might be nearly a volt higher anyway. You can also set the value to "FUL", which means it will perform a normal charge (terminating at the bulk (Constant Voltage) setting, setting 26).
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Post by KG666 » Tue, 10 Jan 2017, 04:47

THX Coulomb for the time and the info!!!

i have set "back to battery mode" = full

because if i read it right , when the solarpanels are connected it will not be activated that much (hope not)
full = bulk = 57.4v

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Post by KG666 » Tue, 10 Jan 2017, 04:59

btw , some pictures of the installation :

Image
Image
Image

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Post by solamahn » Thu, 12 Jan 2017, 12:49

Has anyone tried the hybrid mpi models. I see 3k, 5.5k and 10k have AS4777. I assume 5k is not included because of 900v max pv input voltage but 10k model is also 900v
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Post by paulvk » Sat, 14 Jan 2017, 02:50

I have been looking at the solar charger:
Two dual TO220 diodes V30200C 15Amp x 2 at 200v thus a limit of 60 amps (another part running at full rating)
Current sense is 6 x R002 surface mount (.002 ohms) in two sets of 3

There are two chargers on the board running in parallel.
So by adding another R002 on each set we should come close to getting 80 amps when it thinks its 60 amps.
But we need to change the two dual diodes so would need to go to dual 25amp
Looking I can only find dual 40amp 170V in TO-3PW package but the mosfets IRFB4321 are only 150V 85amps so they should be ok at 170v.

Might do one and see how it goes.

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Post by weber » Sat, 14 Jan 2017, 04:42

Hi paulvk. That's interesting. I suspect you might have to upgrade the MOSFETs to a higher current rating as well, despite their nominal rating.

On the subject of circuit modifications: I recently became curious as to where that 50 watts is going when the PIP is in battery mode with no load. It has to appear as heat somewhere. So I left the inverter doing nothing for a few hours, then I took the cover off and waved an IR thermometer around. The hottest thing by far was the large toroidal inductor in the upper left of the main PCB. It was running at over 100°C.

I'm guessing it is part of an LC filter on the inverter output, intended to block the PWM frequency, leaving clean 50 Hz. I assume the PWM frequency is more than 20 kHz. But because the inductor is wound with solid 1.3 mm diameter wire [Edit: Turned out to be trifilar 1.45 mm], not litz wire like the other inductors, it is behaving more like a resistor than an inductor, due to skin effect at the PWM frequency.

I calculated that litz wire made of 35 strands of 0.2 mm dia should be suitable.
http://www.ebay.com.au/itm/Litz-Wire-35 ... 6da56366ac

But I've balked at disassembling a PIP and desoldering and unwinding the inductor to (a) count the turns, and (b) measure the wire length.

If someone else was to do this. Then take the risk to order the litz wire and rewind the inductor, and measure the new standby battery consumption, they might become a PIP/Axpert legend. Image
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Post by offgridQLD » Sat, 14 Jan 2017, 05:19

Weber, I have a spare pip that hasn't been installed yet. I am happy to try it on. Thanks for doing all the ground work. I will order the litz wire and update when it arrives.

Thanks

Kurt.
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Post by weber » Sat, 14 Jan 2017, 05:38

offgridQLD wrote: Weber, I have a spare pip that hasn't been installed yet. I am happy to try it on. Thanks for doing all the ground work. I will order the litz wire and update when it arrives.

That's awesome Kurt!

I tried to estimate the length of wire needed, from measurements of the wound toroid, but it's completely covered by multiple layers, so it's impossible to tell how much is core and how much is wire. So the only way to be sure is to unwind it and measure it. At least the re-winding should be much easier than the un-winding (and the original winding) as the litz wire will be so much more flexible.

Of course the whole 50 watts won't be dissipated in that inductor. But I wouldn't be surprised to learn that half of it is.
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Post by weber » Sat, 14 Jan 2017, 05:56

Software-only AC input power meter

We recently had a request in this thread for a suitable device to measure the AC input power to a PIP/Axpert. The PIP itself measures every other power flow, but not AC input power. This is the power consumed from the utility (or a generator) when the PIP is operating in bypass mode. It is used to both power the AC loads and charge the battery.

Coulomb and I are creating an internet dashboard for our "Monolith" standalone-power-system/UPS, and we want it to display and log _all_ the power flows, including how much we use from the utility.

I realised we could avoid the cost of a power-meter-with-comms if we knew what the efficiency curve was for the PIP's charger. i.e. its efficiency as a function of charge current. We could then take the PIP's measurements of charge current and charge power, subtract the part that was coming from the SCC, and work backwards to calculate the AC input power being used for charging. Then add to that the PIP's measurement of the AC power going to the loads.

So Coulomb and I set about measuring the AC input power with no loads and no solar input, while charging a LiFePO₄ battery at 2, 10, 20, 30, 40, 50 and 60 amps. We used an ATA Power Mate (plug-in true-RMS power-meter) to measure the AC input power. But our attempts to fit sensible curves to the results were hampered by the low resolution of our battery current measurements. We couldn't rely on the PIP's own measurements as these only have a resolution of 1 amp.

Our problems were solved when Coulomb remembered the hidden 4.5 digit mode of our Fluke 87 III multimeters. We had to look up how to do it -- hold the backlight button down for 1 second. Then we got sufficient current resolution by putting the multimeter probes on the kelvin connections of our current shunt.

After much fiddling about in Excel we had a simple equation that fit the measurements to within +- 3 watts. Some more work and we had a zero-hardware AC-input-power gauge on our Monolith internet dashboard. And soon we will be logging it to our daily log files. All this is running on a Beaglebone Black credit-card-size computer, over WiFi, using the Node-RED visual programming tool.
Last edited by weber on Sat, 14 Jan 2017, 06:23, edited 1 time in total.
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