Sorotec Inverter Error Codes - REVO Fault Code Guide Pakistan

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Key Takeaways

• Sorotec, made by Shenzhen Soro Electronics, ships at least two incompatible fault code tables under the REVO name, so the same number means different things on different models.
• On the REVO VM II platform, fault 11 is over temperature above 85°C and fault 07 is low battery. On the Axpert-style REVO table, 02 is over temperature, 04 is low battery, and codes 51 to 59 exist.
• Fault 18, power feedback protection, is checked by confirming L and N are not connected reversely in any unit, which makes it one of the most Pakistani faults on the list.
• Faults 02 and 03 define the output window as below 180VAC or above 260VAC, against a Pakistani nominal of 230V with grid-code limits of ±5% normal and ±10% contingency.
• REVO VM II 3500-24 and 5500-48 carry a 100A MPPT charger, 500 VDC maximum PV array voltage and parallel operation up to nine units; the Pakistan distributor lists a 5-year warranty on the REVO HES 6kW.

Why does Sorotec ship two completely different fault code tables?

Sorotec, of Shenzhen, builds several distinct hardware platforms and sells them all under the REVO badge, including REVO II, REVO VM II and VM II Pro, REVO VM IV, REVO HM, REVO HES, REVO HMT. These are not cosmetic variations. They come from different design generations with different firmware, and the firmware writes the number on your screen.

The result is a genuine trap. A REVO VM II manual defines fault 01 as bus voltage too high. An Axpert-style REVO manual defines fault 01 as fan locked when the inverter is off. Both are correct for their own hardware. A technician who applies one table to the other replaces a fan when the DC bus is over-volting.

The uncomfortable part, plainly. This is how white-label inverter manufacturing works, and Pakistani dealers rarely warn buyers about it. The wider Voltronic-derived ecosystem has at least a third numbering scheme in circulation, in which 13 is over current or surge, 14 is bus voltage too low, 15 is inverter self-check failure and 22 is output voltage too low. If someone quotes a code meaning without first asking your exact model, treat the diagnosis as unverified.

How do you tell which Sorotec code table your REVO uses?

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Three quick tests, in order of reliability.

Test one, the 50s. If your fault table contains codes in the 51 to 59 range, you have the Axpert-style table. The VM II table stops at 26 and has nothing in the 50s.

Test two, the phase-loss codes. If your table lists 13, 14 and 15 as A, B and C phase lost, and 23 to 26 as PV faults, you have the VM II table. The Axpert-style table has no phase-loss codes and puts PV over-voltage at 59.

Test three, code 11. On the VM II table, 11 is over temperature. On the Axpert-style table, 11 does not exist as a fault at all.

No manual? Photograph the model plate and ask the dealer, in writing, for the fault table for that exact model number before any repair is quoted. A REVO II is not a REVO VM II, and a REVO VM II is not a REVO VM IV.

What do the REVO VM II fault codes mean?

The table used by the 3 to 5.5 kVA VM II platform.

• 01 Bus voltage is too high. Restart once; a repeat means the repair centre.
• 02 Inverter voltage is too high and 03 Inverter voltage is too low. Grouped in troubleshooting as output abnormal, defined as inverter voltage below 180VAC or above 260VAC. Reduce load; if it persists, return the unit. The same pair is also described as output voltage unbalanced.
• 04 Bus soft start failure.
• 05 Overload fault. The inverter overloading 100% until the overload timer reaches its upper limit. Switch off equipment.
• 06 Output short circuited. Check wiring and remove the abnormal load.
• 07 Battery voltage is too low.
• 08 Inverter soft start failure.
• 09 Bus voltage is too low. Restart once; a repeat means the repair centre.
• 10 Parallel fault. Check whether the connection between inverters is loose.
• 11 Over temperature. Internal component temperature above 85°C. Check ventilation around the equipment.
• 12 Battery voltage is too high. Check that battery specification and quantity meet requirements. If genuinely over-charged, the manual sends the unit back.

One honesty note. The same manual's troubleshooting section lumps "fault code 01/04/06" under internal components failed, return to repair centre, which sits awkwardly beside 06 being defined as an output short circuit in the code table. Where a manual contradicts itself, trust the specific entry, and do not let a workshop use the grouped line to justify a board replacement when the real problem was a shorted extension lead.

What do the parallel, phase and PV codes 13 to 26 mean?

• 13, 14, 15 - A, B or C phase lost. Check whether three-phase power is connected and whether the inverter is set to three-phase parallel.
• 16 - AC output voltage and frequency setting is different. Output voltage and frequency must be set identically on every inverter in the bank.
• 17 - AC input voltage and frequency detected different. Input settings must match across the bank.
• 18 - Power feedback protection. Restart; check that L and N cables are not connected reversely in any inverter; for a single-phase parallel system the sharing cables must be connected in all inverters; for a three-phase system they must be connected between inverters on the same phase and disconnected between different phases.
• 19 - Firmware version inconsistent. Update every inverter to the same version.
• 20 - Current sharing fault.
• 23 - PV is over current. Treated as over current or surge; remove the abnormal load or check the PV input.
• 24 - PV over temperature. 25 - PV overload. 26 - PV step-up converter fault.

What do the Sorotec warning codes mean?

On the VM II table, the codes are 01 battery voltage too low, 02 input voltage too low, 03 input voltage too high, 04 overload, 05 over temperature, 06 fan locked when inverter is on, 07 battery voltage too high, 21 PV voltage too low, 22 PV voltage too high.

Warning 22 carries a consequence most owners never connect. The manual explains that if PV input voltage is higher than specification the output power will be derated, and at that point, if connected loads exceed the derated output power, it causes overload. So an over-long string does not just risk a PV fault; it quietly reduces how much load your inverter can carry, and then you get an overload you blame on the fridge. The fix is fewer PV modules in series, or less load.

The warning numbering is platform-specific too. On the Axpert-style REVO table the warnings run 01 fan locked when on, 02 over temperature, 03 battery over-charged, 04 low battery, 07 overload, 10 output power derating, 15 PV energy is low, 16 high AC input above 280VAC during bus soft start, and 32 communication failure between inverter and remote display panel.

Which Sorotec faults come from Pakistani wiring, heat and grid?

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Fault 18 is the Pakistan special. Power feedback protection is checked by verifying that live and neutral are not reversed. In a country where socket polarity is inconsistent and a "changeover" is often a knife switch fitted by a mistri, reversed L and N is not exotic. Check it with a multimeter before anybody mentions a board fault.

Fault 11 at 85°C is a low bar for a Pakistani summer. Ambient in Multan, Sukkur or Jacobabad regularly exceeds 45°C, and a wall-mounted inverter with a dust-loaded heatsink in still air reaches 85°C internally without any component being defective. Clear the fins with dry compressed air and stop mounting inverters above battery banks.

Faults 02 and 03 track your feeder. The 180V to 260V window is wider than the grid code's legal band of roughly 218.5V to 253V around a 230V nominal, so hitting 02 or 03 on the utility side means your supply is well outside what the DISCO is meant to deliver. Record the voltage and the time of day.

Warning 22 and fault 23 are winter problems. String open-circuit voltage rises as cell temperature falls, so a string sized on a hot afternoon can breach the limit on a cold January morning. The VM II specifies a 500 VDC maximum PV array voltage; design against the coldest expected morning.

Can you read Sorotec faults in the Solarman app?

Partly, with a caveat worth stating honestly. Sorotec's own pages describe monitoring through "our monitoring APP and portal" and list built-in Wi-Fi on the REVO VM IV, without naming a platform. In Pakistan, most REVO installations are monitored through a generic stick logger registered on SOLARMAN Smart, because SolarmanPV loggers are the most widely used option here.

If your installer supplied a Solarman stick, create a plant in the app, choose add logger, find the logger's hotspot named AP followed by a serial number, connect with the password printed on the label, then open 10.10.100.254 in a browser and use Quick Setup to point it at your home Wi-Fi.

The caveat is that the dongle is dealer-supplied hardware, not Sorotec firmware, and the app shows whatever the logger can read over RS485. Do not assume it names the fault as clearly as the LCD does. Photograph the inverter's own screen before power-cycling anything.

When should you stop and call a technician?

Stop and call if the fault is 04 bus soft start failure or 08 inverter soft start failure, or if 01 or 09 returns immediately after one restart as those are DC bus and power-stage problems. Stop if 12 is present and the bank really is over-voltage, an over-charge event around expensive cells. Stop, and check wiring first, if 18 appears, since reversed L and N is a shock hazard in the house as well as a fault in the inverter. Stop if you smell hot insulation or see discolouration at any terminal.

One clean restart is the limit of owner-level troubleshooting, namely AC output breaker off, PV isolator off, battery breaker off, wait three minutes for the bus capacitors to bleed down, then power up in reverse order. If the code returns within seconds, each further restart drives inrush through a component that has already failed.

Finally, on money. We found no published Pakistani retail price for the Sorotec REVO range on the distributor's own site as of July 2026, only a stated 5-year warranty on the REVO HES 6kW. Where local pricing is not published, get the quotation, model number and warranty terms in writing on a letterhead before payment.

Frequently Asked Questions

Does Sorotec use one fault code table across all REVO models?

No. At least two different tables ship under the REVO name. On the VM II platform code 11 is over temperature and code 07 is low battery. On the Axpert-style table code 02 is over temperature and code 04 is low battery. Check your own manual.

What does Sorotec fault 18 power feedback protection mean?

Fault 18 means the inverter is detecting power pushed back into its AC input. The manual's first checks are to restart, then confirm L and N are not reversed in any unit, then confirm the current-sharing cables are correct across the parallel bank.

At what temperature does a Sorotec REVO VM II trip on fault 11?

The VM II manual defines fault 11 as internal inverter component temperature above 85°C, and the remedy is to check that the area around the equipment is well ventilated. That is a lower threshold than the 100°C used on some other platforms.

References

• VM II 3-5.5 kVA hybrid inverter user manual with the REVO VM II fault and warning tables
• VM III TWIN 4K/6K hybrid inverter user manual, Axpert-style fault table
• Hybrid solar inverter/charger 1.5/3.6/5.6 kVA manual, third Voltronic-family numbering
• Sorotec REVO VM II series product page, Shenzhen Soro Electronics
• Sorotec REVO VM IV product page
• Sorotec Pakistan, REVO HES 6kW listing
• Sunways REVO-II series user manual, ManualsLib
• Solarman stick logger Wi-Fi configuration guide
• SOLARMAN stick logger product page
• NEPRA Draft Grid Code 2021