Warning What does this mean?
Your system is down or running degraded, but this is not an immediate safety danger. Work through the safe steps below.
GoodWe Inverter Error 30 — What the 1.5V Reference Fault Means
Error 30 means the inverter's internal 1.5V reference voltage circuit has failed — GoodWe's description is 'REF 1.5V Failure: 1.5V reference voltage exceeds the limit.' The reference circuit provides the stable baseline the control board uses for all its voltage and current measurements, so when it drifts out of limits the inverter cannot trust its own readings and shuts down to stay safe. This is an internal hardware fault with no user-side fix. Try one power-cycle using the external AC and DC switches; if Error 30 returns, contact your installer or GoodWe's aftersales service. Never open the inverter.
What should I do first?
Two quick questions — we'll point you to the right starting point.
Is this code still showing on your inverter's display?
Is your system producing power right now?
What this code means
Every measurement your inverter makes — grid voltage, grid current, DC input voltage, leakage current — is really a comparison against a known-stable voltage generated inside the unit. That known-stable voltage comes from a precision reference circuit, and on these GoodWe models the key reference rail is 1.5 volts. Error 30 fires when the control board detects that this reference has wandered outside its allowed window: the "ruler" itself is bent, so every measurement made with it becomes suspect.
That is why the inverter's response is uncompromising. An inverter that cannot trust its own voltage and current readings cannot safely decide when to stay connected to the grid, when to disconnect, or how much power to push — so it stops. GoodWe documents the fault plainly in its error tables ("REF 1.5V Failure — 1.5V reference voltage exceeds the limit") and, in its newer hybrid-series manuals, under the equivalent fault name "1.5V Reference Abnormal" with the cause given as "reference circuit fault." In both generations of documentation the handling is identical: power-cycle once, and if the fault persists, it is a dealer or aftersales service matter. There is deliberately no deeper user troubleshooting, because the fault lives on the control board, under the sealed cover, at component level.
What is this downtime costing you?
Rough estimate while your system isn't producing. Adjust the numbers to match your setup.
≈ – kWh of lost production per day.
Estimate only — assumes ~80% real-world output vs. nameplate. Actual losses depend on weather, shading, panel direction, and your tariff.
Common causes
- Failure of a component in the internal 1.5V reference circuit — the precision voltage reference IC or its supporting circuitry drifting or dying with age and heat.
- Board-level damage from a power surge or lightning-induced transient reaching the control electronics.
- Aging-related drift of the reference beyond its tolerance window after years of thermal cycling.
- A wider control-board fault where the reference circuit is the first thing the self-checks catch.
Safe steps to try
Work top to bottom, ticking off each step as you complete it. 0 of 5 done.
Is your inverter still under warranty?
Before paying for a repair, check — your installer may fix this free.
Based on typical standard warranty terms — always confirm with your warranty card or installer paperwork, as terms vary by model, region, and purchase date.
When to call an electrician
If Error 30 reappears after the power-cycle, contact your installer or GoodWe's dealer/aftersales service center without further delay — GoodWe's manual states this explicitly: if the fault persists, contact the dealer or aftersales service center. Reference-circuit faults require board-level diagnosis and usually mean control-board repair or replacement, which is strictly service work. If the unit is under warranty, insist on authorized service so the warranty stays intact, and give the technician the error code plus a note of whether the power-cycle changed anything.
Frequently asked questions
What does a reference voltage actually do?
It is the inverter's internal measuring standard — a rock-steady 1.5V against which all the real-world voltages and currents are compared. If the standard itself drifts, every protection decision based on those measurements becomes unreliable, which is why the inverter refuses to run.
Could this be caused by my grid supply?
No. The 1.5V reference is generated entirely inside the inverter by its own circuitry. Grid conditions cannot push it out of limits; this is an internal electronics fault.
Will a firmware update fix Error 30?
No. Firmware cannot repair a drifting or failed hardware reference circuit. This needs physical diagnosis at service level.
Is Error 30 dangerous?
Not directly — the inverter shuts itself down, which is the safe response. The risk it protects against is an inverter operating with untrustworthy measurements, which could otherwise misjudge grid conditions. The main cost to you is downtime.
How will the technician diagnose it?
With the unit open on a bench (service personnel only), they measure the reference rail directly and check the surrounding circuitry. Depending on what they find, the fix ranges from component replacement to a full control-board swap.
Need a professional?
This fault may need professional diagnosis. Contact a qualified solar electrician in your area.
Sources: meaning and troubleshooting verified against the manufacturer's documentation — GoodWe MT G2 Series Grid-Tied PV Inverter User Manual, Section 5.9 'Error Message Description' — Error 30 'REF 1.5V Failure: 1.5V reference voltage exceeds the limit'; GoodWe EH Series User Manual fault table — F76 '1.5V Reference Abnormal: Reference circuit fault'; handling: disconnect AC and DC switches, wait 5 minutes, reconnect, contact dealer/aftersales if it persists (goodwe.com).