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Axpert King MPPT blown and Voltronic response


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Hi
I installed a Axper King inverter with 12 x JAP72S09-340/SC 340W panels in a 2S-6P configuration. The MPPT controller blew 2 weeks ago after 6 months of operation and I sent it back for a warranty claim.
The supplier responded with
"We need to change your Solar Charge Controller that got damaged due to the wrong connection of
the solar panel configuration. Incorrect input Voltage and Current. The ---5KING inverter should be 3 in series with a maximum of 4 strings in parallel of +- 330w –
360w solar panels."

I responded with the manufacturer spec stating a 60-115v PV voltage with 4000w limit. My panels are 37.74v max power and with 2S at 75.48V. Well within the manufacture spec.
The supplier then contacted voltronic and they responded with:

"Hi -----

For this kind of panels we suggest 3 in series and 4 strings.

 The current of 6 strings is over the limitation of the solar charger, it may increase the risk to the MOSFET in the charger controller..

Thanks."

So by Voltronic's own admission their device can not function under the electrical specifications they themselves provide?

Any opinions on this matter?

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WOW. Even by their incredibly low standards, both in customer service and technical competence, this is surely a new low.

As @Coulomb and others have documented endlessly, and I have personally experienced, these inverters do not work properly in 3S configuration with 72 cell panels.

So now we can't use 2S and we can't use 3S.  I guess the only valid answer is to stop using Voltronic's products completely.  Darwin will surely smile when they go into well-deserved bankruptcy...

Edited by Calvin
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Technically you probably can insist on a repair under the Consumer Protection Act (any lawyers out there?)  Nowhere in there brochures or installation manuals do they mention these restrictions.  Even now they say "we suggest" rather than "your warranty will be void if ...".

In practice name and shame may be an easier option.  Start by telling us who the supplier is, so that we can avoid them.

Or say to them "OOPS - did I say 2S6P?  I meant 3S4P!" 🤪

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Posted (edited)

Lol. Name and shame works for me. Is it allowed on here?

CPA yes, false claims of capabilities and misleading marketing.

I bought the unit from an online vendor who is a reseller, very good service. He is willing to pay for the repairs. It is his supplier that is making these statements together with voltronic.

It really bugs me, my configuration should not come close to the technical spec unless they are doing something dodgy. I have asked for the blown unit back to do an autopsy.

Edited by overdrive
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1 hour ago, overdrive said:

"Hi -----

For this kind of panels we suggest 3 in series and 4 strings.

 The current of 6 strings is over the limitation of the solar charger, it may increase the risk to the MOSFET in the charger controller..

Thanks."

So by Voltronic's own admission their device can not function under the electrical specifications they themselves provide?

Any opinions on this matter?

They need to repair it, are they actually saying they will not repair or replace it?  That is their problem not yours.  If they refuse, go small claims court and make it clear that you did not exceed the specifications and as such you expect a warranty return.

Unless they stated that requirement in their manual, I would simply go small claims.  Your warranty, legally speaking is not with the manufacturer.  It is with whom you bought it.  So not even sure why the reseller is involving you in this.  That is their problem to negotiate.  Unless they can point out which part of the manual you went wrong on.

They aren't doing you some kind of favor, the SA law is clear on this.  If they can't negotiate with their supplier they shouldn't be in the reseller business.

1 hour ago, overdrive said:

Hi
I installed a Axper King inverter with 12 x JAP72S09-340/SC 340W panels in a 2S-6P configuration. The MPPT controller blew 2 weeks ago after 6 months of operation and I sent it back for a warranty claim.
The supplier responded with
"We need to change your Solar Charge Controller that got damaged due to the wrong connection of
the solar panel configuration. Incorrect input Voltage and Current. The ---5KING inverter should be 3 in series with a maximum of 4 strings in parallel of +- 330w –
360w solar panels."

I responded with the manufacturer spec stating a 60-115v PV voltage with 4000w limit. My panels are 37.74v max power and with 2S at 75.48V. Well within the manufacture spec.

Bad service aside, sounds like the 3S will be in spec if the maximum output is 37.74v x 3 = 113.22v?

I was under the impression 4S is where people are having a breakdown?

Edited by Gnome
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Posted (edited)

3S is where people get issues with the king going to 0W output. I had that for 1 month and went to 2S no issue for 5 months.

 

  1. Q: I have a 145 V max PV model. Why doesn't my inverter-charger use any/all of available PV some of the time?

    A: I note that the 145 V figure is the absolute, never-exceed maximum. It's not a "let me see if I can squeeze under that limit" thing. At a panel voltage of 145 V, PV power is limited to zero. At 144 V, the power is restricted to 6.7% of maximum. Even at 130 V, where the power is not restricted at all, the solar charge controller seems to run much hotter, and may limit itself due to temperature. PIP-5048MK (Axpert King) models seem to be particularly sensitive to high PV voltage. What this means in practice is that with 72-cell panels (or 144-half-cell panels), which are the most common type as of 2020, you can only wire them 2S (two panels in series). You can wire as many strings of two panels as needed, but as per FAQ 5, don't exceed 10-20% of rated PV power (rated power is now usually 4000 W for 5 kVA models). Wiring 3S (3 panels in series per string) will almost always lead to trouble if you're using 72-cell panels. 60-cell panels can be run in 3S, and will probably work better in 3S than 2S. Remember also that the Voc of a panel is given at standard operating conditions and 25°C; panel voltage typically increases about 7% at 0°C.

    This problem is becoming worse as panels become larger and larger in power output. Part of how this is achieved is that the cells output a higher voltage than their predecessors.

 

Edited by overdrive
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Looks like you'll have to go to this configuration:

60-cell panels can be run in 3S

Or switch to another inverter to get reliable solar charging.

FYI: Again I'm not condoning the response or how the device operates.  I'm just stating the obvious fact that the above is probably what the device limits should be in the manual

Edited by Gnome
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2 hours ago, Gnome said:

Looks like you'll have to go to this configuration:

60-cell panels can be run in 3S

Voltronics sell a lot of inverters, and operate at the "value" end of the market.  Your SCC happened to pop - sometimes "stuff" happens.  (Had your panels been 3S, they would probably have refused the repair based on the Voltage being out of spec - at least then they may have had a point.)

The fact that the suppliers/manufacturers are now inventing new rules to dodge their warranty obligations in no way means that there is anything wrong with the way your system is configured.  It is just a bunch of sleazy crooks doing their thing.  

(I have 4 of these installed - what was I thinking?😭)

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1 hour ago, Calvin said:

Voltronics sell a lot of inverters, and operate at the "value" end of the market.  Your SCC happened to pop - sometimes "stuff" happens.  (Had your panels been 3S, they would probably have refused the repair based on the Voltage being out of spec - at least then they may have had a point.)

The fact that the suppliers/manufacturers are now inventing new rules to dodge their warranty obligations in no way means that there is anything wrong with the way your system is configured.  It is just a bunch of sleazy crooks doing their thing.  

(I have 4 of these installed - what was I thinking?😭)

This is my view as well, hence my posting it here to highlight how dodgy they are. 

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My own inverters are from 2015, and were one of the last that had the 60 A max solar charge controller. This is before Kings, but I get the impression that the Solar Charge Controllers haven't changed much over the years (apart from the 450 V and 500 V max SCCs, obviously).

It wasn't much longer after I bought mine than the specs changed from PF0.8 to PF1.0, i.e. they allow 5000 W (plus losses) through the 48 V to 400 V DC-DC converter. I've often wondered how much the hardware design changed, if at all, to accommodate these two improvements in specifications (80 A solar charge current, and 5000+ W through the DC-DC). Maybe they just ate into their design margins, and didn't change the hardware at all. I've seen no evidence of changes to the DC-DC MOSFETs, for example. So I wonder if these SCC problems are related to pushing the hardware that much harder (80/60 = 133%).

I also get the impression that the SCCs in the Kings perform worse than the presumably very similar SCCs in Axpert MKS models. If true, I wonder if that's related to the amount of hardware packed into one box (the Kings have the additional AC to DC converter).

Finally, I wonder if they'd get an immediate reduction in warranty claims if they just turned the fans around to blow upwards, as users have been advocating for years.

@overdrive, I wish you well with your mission.

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A friend of mine looked into the Fets on the MPPT controller and found irfb4321 (Vdss @150v) and irf640npbf (Vdss  @200v). I am waiting for my unit back to take a look at what is populated. If the components match then the spec printed on the inverter is, as you say, very close to the margin. He also made a valid argument that heat, i.e current, is a bigger killer of fets than volts. Maybe why voltronic insists on a 3S solar setup. 

I also looked at the fans and thought "why are they backwards?". Yet another baffling design "feature".

Bottom line, King = trouble. 

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  • 2 weeks later...

Got the faulty MPPT unit back today. I disassembled it and found 6 X irfb4115 (104 A, 150 V HEXFET) and 4 X V30200C Diodes "clamped" to the hearsink.

One of the fets on my controller blew for sure, still need to test the rest. The Fet was barely clamped to the heatsink. I am actually surprised the controller lasted 6 months without popping. They use plastic clamps and what looks like a mica isolator strip. No thermal paste.

The rest of the design looks like 80A would be within reach so I can not for the life of me understand voltronic's claim that they require 3S solar panels. 2S 6P gives you +- 76V and at a max of 4000W you would only do 52.6A... they are looking for trouble by making silly statements.

 

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