brunodu31

Dear all After studying the service manual, the internal board layout, the Voltronic SOP, and several teardown pictures, we have developed a working hypothesis regarding the intermittent Error 80 observed on some parallel Axpert/Voltronic 5048MG units. The original Voltronic SOP only addresses LCD flickering by repositioning the MPPT choke wires. However, after a closer analysis of the inverter architecture, we believe the root cause may be broader than the LCD issue. The MPPT choke is physically mounted far away from the MPPT power board. The two wires connecting the choke to the MPPT board (P2/P3) are relatively long and appear to be part of the MPPT switching current loop. These wires carry high current and high dV/dt switching waveforms generated by the MPPT IGBTs/MOSFETs operating at approximately 50 kHz. While the toroidal choke itself should radiate very little magnetic field, the long connecting wires form a large switching loop that is likely to generate both conducted and radiated EMI. Inspection of the inverter shows that these wires run very close to several ribbon cables and communication boards, including boards associated with the parallel system (PAR-P board, PAR communication board, communication board and main board). Our hypothesis is that the switching loop radiates broadband EMI which couples into the nearby ribbon cables and communication circuits. The fundamental switching frequency is only around 50 kHz, but the fast switching edges generate harmonics extending into the MHz range. This may occasionally corrupt communication between the parallel control boards, resulting in Error 80. To investigate this theory, we will first implement the official Voltronic capacitor modification (2.2 µF film capacitor across PV+ and PV−), which should improve differential-mode filtering on the PV input. If the problem persists, we plan to shield the two MPPT choke wires. The proposed design is intended to minimize additional capacitance: each MPPT wire will be routed inside its own PVC insulating tube; the two tubes will be placed side by side; a copper braided shield will surround both tubes; an outer heat-shrink sleeve will provide mechanical protection; the shield will be connected to chassis earth at one end only; significant air spacing will remain between the conductors and the shield in order to keep conductor-to-shield capacitance as low as possible (estimated only a few tens of pF). The objective is not to filter the MPPT current itself, but to contain the radiated electric field generated by the switching loop and prevent coupling into the nearby communication and parallel-control circuitry. At this stage this remains a hypothesis, but it is consistent with: the physical layout of the inverter; the location of the MPPT choke wiring; the proximity of the communication ribbon cables; the Voltronic LCD flicker correction; and the intermittent nature of Error 80.

I found the official Voltronic service manual for the 5048MG platform (2018 version). Interestingly, it confirms the presence of a common-mode choke directly on the PV input, before the MPPT stage. This gives much more credibility to the later Voltronic SOP recommending the addition of a 2.2 µF film capacitor across PV+ and PV−, as it effectively completes the EMI input filter rather than acting as a simple bulk capacitor. It also shows how close the MPPT wiring, control board and communication boards are inside the unit, which may be relevant when investigating communication-related faults such as Error 80. I thought this document could be useful to others working on these inverters. AXPERT MKS II 5KW 230V Service manual 201807A-compressé.pdf

Thank you again for your help. One more question: do you happen to know whether any service schematics, partial schematics, or block diagrams exist for the PIP-5048MG / Axpert MKS II platform? I am particularly interested in understanding: how the parallel communication board is connected internally; whether “CAN data loss” really refers to a physical CAN bus or to a proprietary internal communication channel; where the communication transceivers are located; how the communication board is powered and referenced; how close the MPPT choke wiring is to the communication circuitry; whether Voltronic ever documented the capacitor / wire-routing modification in relation to communication faults such as Error 80. Even a partial schematic of the communication board, parallel board, or MPPT input area would be extremely useful. I fully understand that complete schematics may not be publicly available, but any archived service information, block diagrams, or practical experience would help a lot. Thank you again.

Thank you, that makes sense. I should clarify that I may not have explained my idea very well. I was not considering replacing the existing PV/choke wires with shielded cable. My idea was to keep the existing insulated wires unchanged and, if necessary, add a loosely fitting metallic braid around them as an external shield. The braid would be significantly larger than the cable bundle and separated from the conductors by the existing insulation (and possibly an additional insulating sleeve), in order to keep the capacitance as low as reasonably possible. However, your point about the additional capacitance and the resulting HF currents is very clear. I understand that even a relatively small capacitance may introduce unwanted losses or additional stress in the converters. For now, I will not attempt any shielding modification. I will start with the safer and documented approach: adding the PV input capacitor as described in the Voltronic SOP; keeping PV+ and PV− close together / lightly twisted where possible; improving cable routing away from communication wiring. I will report back after testing.

Dear Coulomb, Thank you very much for your detailed reply and for all the information you have shared. Your comments have been extremely helpful. We already suspected that Error 80 might be related to an EMI issue rather than a firmware issue, and the information you provided, together with the Voltronic SOPs regarding the MPPT choke wire arrangement and the PV capacitor modification, strongly reinforces that hypothesis. My units do not have a removable display. They are 2018 PIP-5048MG / Axpert MKS II units with the 450 V MPPT input and fixed display. Following your advice, I will first implement the hardware modifications before considering any firmware upgrade: rearranging and twisting the MPPT choke wires according to the Voltronic SOP; adding a 2.2 µF / 1200 VDC polypropylene power film capacitor across the PV input terminals of each inverter. I have already ordered the capacitor and will report back with the results once the modifications have been tested. After carefully studying the MPPT wire arrangement SOP, I noticed that Voltronic not only reroutes the wires but also keeps them closely coupled and away from nearby electronics. This seems very consistent with an EMI-related mechanism. I would appreciate your opinion on one additional idea. Do you think there would be any benefit in placing the MPPT choke wires inside a grounded metallic braid or metallic shield connected to protective earth at one end only? My reasoning is that if the issue is caused by high dV/dt on these conductors, a grounded shield could further reduce radiated electric field coupling into the nearby communication and control circuitry. Or do you believe that the capacitor modification and the revised wire routing already address the root cause sufficiently? Thank you again for your help and for sharing your experience with the Axpert platform. Your guidance is greatly appreciated. Kind regards, Eric Giacomini France

Dear Coulomb, Thank you again for your reply and for taking the time to share your experience. First of all, please accept my apologies for the delayed response. Unfortunately, I did not receive any email notification from the forum and only discovered your message recently while reviewing the thread. Your comments regarding high dV/dt on high-voltage PV systems were extremely interesting and may explain several observations I have made on my installation. My system consists of: 2 × PIP-5048MG / Axpert MKS II operating in parallel 450 V MPPT versions Parallel communication board installed Current sharing cable installed Common lithium battery bank The firmware currently installed on both units is: Main firmware (U1): 71.20 I am still trying to retrieve the exact U2 (display/MCU) and DSP firmware versions and will provide them as soon as I have them. I have recently located a copy of firmware version 71.86 which appears to be intended specifically for the PIP-5048MG / Axpert MKS II platform. However, I am hesitant to perform a firmware upgrade because the system is generally operating well and I am concerned about the possibility of a failed update or an unexpected regression. I have not been able to locate a copy of the currently installed 71.20 firmware and therefore I am unsure whether I would be able to revert to the existing version if problems arise. In your opinion: Would you recommend upgrading from 71.20 to 71.86? Have you seen any evidence that later firmware versions improve Error 80 occurrences, parallel communication reliability, or overall stability of parallel systems? Is there any significant risk associated with moving from such an early firmware version to 71.86? Regarding the capacitor modification you mentioned, I managed to find the Voltronic SOP describing the installation of capacitor reference: 31-013730-00G directly across the PV input terminals. Unfortunately, I have not been able to locate this component for sale, nor have I found any technical specifications associated with that reference. Could you please advise: the capacitance value; voltage rating; capacitor technology (polypropylene film, MKP, etc.); whether the modification was introduced specifically to mitigate Error 80 or more generally to reduce EMI and communication disturbances; what specifications should be used if the original Voltronic component is no longer available. Your explanation regarding high dV/dt on the PV wiring causing communication glitches is particularly interesting because it seems consistent with the behaviour observed on my installation. Although Error 80 sometimes occurs during periods of high solar activity, I have also observed a few occurrences during lower PV production conditions, which makes me wonder whether the capacitor modification improves overall communication robustness rather than addressing a single operating condition. As a side note, I have developed a Python-based supervisory system called "Energy Brain" for my installation. The goal was not to replace the inverter firmware but rather to provide higher-level energy management, battery supervision, load control, historical logging and system monitoring while leaving the inverter hardware unchanged. The system is now operating reliably and has significantly improved the behaviour of my installation. Once the project is properly documented and cleaned up, I intend to make it available to the community so that other PIP-5048MG / Axpert users can benefit from it and contribute improvements. Thank you again for all your work and for the knowledge you continue to share with the Axpert community. Kind regards, Eric Giacomini France

Dear Coulomb, First of all, please accept my apologies for the delayed reply. Unfortunately, I did not receive any email notification of your response and only discovered it today while reviewing the forum thread. Thank you very much for your comments. Your explanation regarding the high dV/dt generated by the high-voltage PV strings is extremely interesting and may explain several observations I have made on my installation. My system consists of two PIP-5048MG / Axpert MKS II units operating in parallel. I have occasionally experienced Error 80 ("CAN data loss"), sometimes during periods of high PV activity, but also on a few occasions under lower solar production conditions. I was particularly interested by your mention of the capacitor modification. I have since located the Voltronic SOP describing the installation of capacitor 31-013730-00G directly across the PV input terminals. I would be grateful if you could clarify a few points: Do you know the value and specifications of capacitor 31-013730-00G? Was this modification introduced as a corrective action for Error 80 specifically, or for a broader EMI/noise issue? Have you personally seen Error 80 disappear or significantly improve after this capacitor modification? Is the issue mainly caused by conducted noise on the PV wiring, radiated EMI, or both? Do you know whether later firmware versions (71.82, 71.86, 71.92) contain any improvements related to parallel communications or Error 80? You also mentioned cable routing improvements. Unfortunately, the link referenced in your post is no longer visible to me. Would it be possible to provide the link again or briefly describe the recommended cable arrangement? Thank you again for sharing your experience and technical knowledge. It is greatly appreciated by those of us who continue to operate these otherwise excellent inverters. Kind regards, Eric Giacomini France

Error 80 on Two 5048MG / Axpert MKS II in Parallel – Looking for a Real Technical SolutionHello everyone, I am looking for feedback from users who have operated two or more Voltronic-based inverters in parallel, especially: MPP Solar 5048MG Voltronic Axpert MKS II Rebranded Axpert MKS II derivatives For clarification, the 5048MG is essentially the same hardware platform as the Voltronic Axpert MKS II sold under different brand names in various countries. My installation2 × 5048MG inverters in parallel (single phase) Firmware 71.20 on both units Serial numbers: 92931807100005 92931807100027 Parallel board installed Parallel communication cable installed Current sharing cable installed Identical battery cable lengths Identical AC wiring Common battery bank Same settings on both units Installation performed according to the official Voltronic / MPP Solar parallel installation guide The system generally works very well and can operate for days without any issue. The problemI occasionally receive Fault 80. According to the official parallel installation guide, Fault 80 is simply described as: "CAN data loss" Unfortunately, the official documentation provides almost no technical explanation beyond: check cables restart inverter That is obviously not a serious root-cause analysis. What I have already checkedParallel communication cables Current sharing cables Battery cable lengths AC wiring symmetry Load balancing between inverters Firmware consistency Battery bank sharing Everything appears compliant with the installation guide. What is frustratingI am clearly not the only one experiencing this problem. A large number of users on forums report intermittent Error 80 on 5048MG / Axpert MKS II systems operating in parallel. The fault is often: intermittent difficult to reproduce absent for hours or days triggered during transitions or heavier loads MPP Solar responseI contacted MPP Solar support. Their response was essentially: Frankly, I find this answer disappointing. These inverters are still fully operational and continue to be widely used worldwide. I am not looking to replace two perfectly functional inverters because of a sporadic communication fault. I would much rather understand the actual cause and solve it properly. Questions for experienced usersHave you experienced Error 80 on 5048MG or Axpert MKS II units operating in parallel? Were you able to identify the root cause? Did replacing the parallel communication cable help? Did replacing the current sharing cable help? Did shielding the communication cables help? Did grounding modifications help? Did you find a firmware version that improved stability? Is Error 80 really related to CAN communication, or is it sometimes a symptom of another synchronization issue? Has anyone obtained a genuine technical explanation from Voltronic or MPP Solar? Did anyone completely eliminate Error 80, and if so, how? Additional observationsI have occasionally observed: transient load sharing asymmetry differences in PV production between the two inverters occasional synchronization disturbances rare communication-related warnings However, the system may also run perfectly for days before Error 80 suddenly appears. This makes me suspect that the issue may be related to: parallel communication timing current sharing synchronization CAN communication robustness firmware behavior or a combination of several factors Any technical information, oscilloscope captures, firmware notes, engineering explanations, service manuals, or real-world experience would be greatly appreciated. Thank you very much for your help.