# Wattbench

> Fast, standards-anchored answers on a phone, on the roof. Fault-code libraries, field calculators and AS/NZS explainers for Australian solar installers and electricians.

Wattbench is the field bench for solar installers and electricians in Australia: fault-code libraries for the major inverter and battery brands, standards-anchored field calculators, and AS/NZS explainers, built to answer fast on a phone, on the roof. Every technical figure is traceable to its source (manufacturer documentation or the AS/NZS standards), calculators are estimates for guidance rather than compliance certificates, and nothing is fabricated: where a figure isn't sourced we leave it blank and say so. Australian English, currency in AUD, SAA-accredited practice. 15 brands and 550 documented fault codes, 18 calculators, 16 explainers and 55 glossary terms, all free to read, no login. Last site-wide review: August 2026.

## Fault code libraries
Documented inverter and battery error / alarm codes by manufacturer, rewritten so the cause and the fix read fast on a roof.
- [Huawei Inverter Error Codes](https://wattbench.ai/huawei-inverter-error-codes): Huawei SUN2000 alarm reference with audience-separated, source-linked remedies for current M2 and M3 families; broader residential and backup codes remain explicitly unverified for those families.
- [Sungrow Alarm Codes](https://wattbench.ai/sungrow-alarm-codes): A searchable Sungrow fault reference with current SH5T–SH25T remedies separated from earlier SH/RT/RS, string-inverter, battery and BDC records.
- [Solis Alarm Codes](https://wattbench.ai/solis-alarm-codes): Solis alarm vocabulary from official service material, with owner-safe and installer guidance while exact Australian model and firmware applicability remains blank.
- [Growatt Error Codes](https://wattbench.ai/growatt-error-codes): Current MOD XH codes separated from legacy TL/MTL search terms, with official remedies only where the exact current manual supports them.
- [GoodWe Error Codes](https://wattbench.ai/goodwe-error-codes): GoodWe inverter error codes for grid, isolation, temperature and internal faults, with clear guidance on self-recovery versus service.
- [Fronius Error Codes](https://wattbench.ai/fronius-error-codes): Common Fronius State codes, including the Australian Volt-Watt and Volt-VAr grid-protection states, explained for owners and installers.
- [SMA Error Codes](https://wattbench.ai/sma-error-codes): SMA event-code reference with source-linked remedies for Australian Sunny Tripower X models and explicit boundaries around older Sunny Boy and mixed-family records.
- [Enphase Microinverter Error Codes](https://wattbench.ai/enphase-microinverter-error-codes): Enphase IQ event reference with current official remedies separated from legacy event vocabulary retained through labelled secondary sources.
- [SolaX Inverter Error Codes](https://wattbench.ai/solax-inverter-error-codes): Current X1/X3-Hybrid G4 faults with source-linked remedies, kept separate from remedy-blank legacy X-Hybrid C1 and DM9000 entries.
- [Deye Inverter Fault Codes](https://wattbench.ai/deye-inverter-fault-codes): Deye SG04LP3-AU fault-table guidance, with deployed-firmware F08/F35 residues labelled and left without unsupported remedies.
- [Tesla Powerwall Alert Codes](https://wattbench.ai/tesla-powerwall-alert-codes): What Tesla Powerwall's app alerts mean, from Breaker Open to Storm Watch, and what to do about them.
- [Sigenergy SigenStor Fault Codes](https://wattbench.ai/sigenergy-sigenstor-fault-codes): Common SigenStor alarms (the 1000-series inverter codes) explained, with what each points to and what to check.
- [FoxESS Inverter Error Codes](https://wattbench.ai/foxess-inverter-error-codes): FoxESS hybrid and R-series alarms with separate owner-safe checks and source-linked installer remedies.
- [Sofar Inverter Error Codes](https://wattbench.ai/sofar-inverter-error-codes): Legacy Sofar ME3000SP ID codes anchored to the official manual, without inferring the same remedies for HYD or later inverter families.
- [Hoymiles Microinverter Error Codes](https://wattbench.ai/hoymiles-microinverter-error-codes): Current official HMS/HMT alarms and remedies, separated from community-only OpenDTU decoder entries that remain remedy-blank.

## Calculators
Transparent, in-browser field calculators, anchored to AS/NZS where a standard applies. No sign-up is required; signed-in users can deliberately save a result.
- [Solar System Size Calculator](https://wattbench.ai/solar-system-size-calculator): Turn your daily energy use, location-specific sun hours and entered system losses into an indicative array size and panel count.
- [Solar Payback Calculator](https://wattbench.ai/solar-payback-calculator): Estimate annual savings and payback period from system cost, generation, self-consumption, electricity rate and feed-in tariff.
- [Solar Panel Power Density Calculator](https://wattbench.ai/solar-panel-density-calculator): From rated power and module dimensions, compute power density in W/m², module efficiency and panels needed per kilowatt.
- [Single or Three-Phase Supply Check](https://wattbench.ai/single-or-three-phase-power): Use visible main-switch or meter clues to identify a likely single- or three-phase supply without opening the switchboard.
- [Three-Phase Load Balance Worksheet](https://wattbench.ai/three-phase-load-balance-worksheet): Compare entered phase currents, identify the highest and lowest phase, and quantify the spread without asserting a compliance limit.
- [Solar Battery Size Calculator](https://wattbench.ai/solar-battery-size-calculator): Size a home battery from your overnight energy use, days of autonomy, depth of discharge and round-trip efficiency.
- [Battery Backup Runtime Calculator](https://wattbench.ai/battery-backup-runtime-calculator): Estimate how long a battery can support a nominated essential load from usable capacity, backup reserve and conversion efficiency.
- [Battery Charge-Time & Surplus Planner](https://wattbench.ai/battery-charge-time-planner): Estimate energy needed and charge time from usable capacity, starting and target state of charge, surplus power and entered efficiency.
- [Essential Load Schedule](https://wattbench.ai/essential-load-schedule): Turn entered continuous loads and daily run-times into a simple backup power and energy schedule.
- [Solar STC Certificate Estimate (Australia)](https://wattbench.ai/solar-stc-rebate-calculator): Estimate certificate count and an entered gross value from system size, zone rating, deeming years and certificate price.
- [Battery STC & WA Rebate Check](https://wattbench.ai/battery-stc-wa-rebate-check): Estimate battery STCs from the compliance-certification date and capacity, with a conditional WA programme amount for Synergy or Horizon Power areas.
- [Solar Cable Voltage Drop Calculator](https://wattbench.ai/solar-cable-voltage-drop-calculator): Work out voltage drop on a DC string or single-phase AC run from the entered length, current, conductor size, voltage and material.
- [AC Voltage Rise Worksheet](https://wattbench.ai/ac-voltage-rise-worksheet): Compare two entered voltage readings and document the rise in volts and percentage without applying a compliance verdict.
- [Cable Sizing Calculator](https://wattbench.ai/solar-cable-sizing-calculator): Find the minimum conductor size that keeps a DC string or AC run under its voltage-drop limit, then round up to the next standard cable size, with the resulting drop shown.
- [Roof Direction & Pitch Check](https://wattbench.ai/solar-tilt-orientation-calculator): Record a roof's direction and pitch, then read source-backed generation-timing guidance without an invented yield percentage.
- [Solar String Sizing Calculator](https://wattbench.ai/solar-string-sizing-calculator): Work out how many panels can go in series on a string, within the inverter's MPPT window and under the maximum system voltage, using temperature-corrected module voltages.
- [Module & Inverter Compatibility Worksheet](https://wattbench.ai/module-inverter-compatibility-worksheet): Compare entered string voltage and current against documented inverter input limits at the design conditions you supply.
- [DC:AC Ratio (Inverter Load Ratio) Calculator](https://wattbench.ai/solar-dc-ac-ratio-calculator): Calculate the ratio of entered array DC capacity to inverter AC rating, without prescribing an unsupported design band.

## Troubleshooting playbooks
- [Inverter Not Producing Power](https://wattbench.ai/troubleshooting/inverter-not-producing-power): A safe, ordered triage for a system showing zero generation, from site conditions and monitoring through to the fault record an installer needs.
- [Solar System Producing Less Than Expected](https://wattbench.ai/troubleshooting/solar-system-producing-less-than-expected): Separate normal variation from a real performance issue using like-for-like periods, monitoring evidence and a structured site handover.
- [Grid Overvoltage and Repeated Inverter Tripping](https://wattbench.ai/troubleshooting/grid-overvoltage-inverter-tripping): Collect the evidence needed to distinguish a network condition, site voltage rise, settings issue or installation problem without guessing at the cause.
- [Home Battery Not Charging](https://wattbench.ai/troubleshooting/battery-not-charging): Work through operating mode, reserve settings, solar availability, communications and fault evidence before escalating a battery issue.
- [Solar Commissioning Handover Checklist](https://wattbench.ai/troubleshooting/solar-commissioning-handover-checklist): A practical record of the information, access and evidence that should leave the site with the customer and installer team.
- [Solar Monitoring Offline or Not Updating](https://wattbench.ai/troubleshooting/solar-monitoring-offline): Separate a monitoring or communications outage from a generation fault and package the evidence needed for support.
- [Inverter Intermittently Restarting](https://wattbench.ai/troubleshooting/inverter-intermittent-restarts): Build a timestamped pattern for repeated restarts without masking protection events or guessing at the cause.
- [Solar Insulation or Earth-Leakage Alarm](https://wattbench.ai/troubleshooting/solar-insulation-earth-leakage-alarm): Treat insulation and leakage warnings as safety events, record the conditions and hand over a useful evidence pack.
- [Home Battery Not Discharging](https://wattbench.ai/troubleshooting/battery-not-discharging): Check reserve, schedules, operating mode, site demand and communications before escalating a battery that remains idle.
- [Battery Backup Did Not Operate](https://wattbench.ai/troubleshooting/battery-backup-failed): Record the outage, essential-load behaviour and battery state needed to assess a backup event.
- [Solar Circuit Repeatedly Tripping](https://wattbench.ai/troubleshooting/solar-circuit-nuisance-tripping): Capture when a protective device operates and escalate without repeatedly resetting a potentially unsafe circuit.
- [Export Control or Meter Commissioning Check](https://wattbench.ai/troubleshooting/export-control-meter-commissioning): A field record for systems that export unexpectedly, remain capped or show implausible power-flow direction.
- [Post-Storm Solar System Check](https://wattbench.ai/troubleshooting/post-storm-solar-inspection): A safe ground-level check after hail, wind, lightning, flooding or debris impact, with clear stop conditions.

## Explainers
Guides to the technology and grid rules behind Australian solar systems.
- [HJT Solar Technology, Explained](https://wattbench.ai/hjt-solar-technology): How heterojunction cells use passivating contacts, what the architecture can support, and which exact-module figures installers must verify.
- [Solar Cell Busbars & Multi-Busbar Design](https://wattbench.ai/solar-cell-busbars): How fingers and collectors balance shading and resistance, why conductor count is not a quality score, and what installers should verify.
- [AC vs DC Solar Panels](https://wattbench.ai/ac-vs-dc-solar-panels): Trace conversion, MPPT, monitoring and battery coupling through string, optimiser and microinverter designs before choosing an architecture.
- [Solar Panel Orientation & Tilt](https://wattbench.ai/solar-panel-orientation): A field workflow for matching azimuth and tilt to shade, interval load, tariffs, export limits, storage and the usable roof.
- [How to Read a Solar Panel Datasheet](https://wattbench.ai/reading-a-solar-datasheet): Verify exact module identity, rating conditions, electrical and mechanical limits, approvals and warranty documents without borrowing generic figures.
- [TOPCon Solar Cells, Explained](https://wattbench.ai/topcon-solar-cells): How TOPCon's tunnel-oxide passivating contact works, why it became mainstream, and which module-level figures installers must verify.
- [Bifacial Solar Panels, Explained](https://wattbench.ai/bifacial-solar-panels): How rear irradiance, bifaciality and array geometry affect output and current, and what installers must verify before relying on a gain estimate.
- [LFP vs NMC: Home Battery Chemistry](https://wattbench.ai/lfp-vs-nmc-home-batteries): A field-safe comparison of LFP and NMC that separates chemistry tendencies from the exact product, warranty, installation and support evidence that decides suitability.
- [Solar Export Limiting, Explained](https://wattbench.ai/solar-export-limiting): How to read an Australian connection approval, distinguish fixed, zero and flexible export arrangements, and capture evidence without guessing network settings.
- [Virtual Power Plants (VPP), Explained](https://wattbench.ai/virtual-power-plants): How to separate VPP capability, enrolment and live dispatch, compare contract terms, and triage unexpected battery behaviour without changing settings blindly.
- [Microinverters vs String Inverters](https://wattbench.ai/microinverters-vs-string-inverters): Compare exact microinverter and string-inverter designs across MPPT allocation, shade, monitoring, failure boundaries and service access.
- [Module and Inverter Compatibility](https://wattbench.ai/module-inverter-compatibility): A complete compatibility check covering cold Voc, MPPT operation, current, parallel strings, connectors and exact model documentation.
- [Battery Backup Architecture and Essential Loads](https://wattbench.ai/battery-backup-architecture-essential-loads): How energy, power, transfer equipment and backed-up circuits combine to determine real outage behaviour.
- [Export-Control Commissioning](https://wattbench.ai/export-control-commissioning): Commission export control from the connection approval through metering, CT direction, phase mapping and measured response.
- [Grid-Voltage Investigations](https://wattbench.ai/grid-voltage-investigation): Build a defensible evidence chain from inverter events, named measurement points, site voltage rise and network escalation.
- [Solar and Battery Commissioning Evidence Packs](https://wattbench.ai/commissioning-evidence-pack): What to retain so another competent person can understand the approved design, installed system, tests, changes and customer handover.

## Standards & reference
- [Standards reference](https://wattbench.ai/standards): Scope of the 11 core AS/NZS and IEC standards behind Australian solar: AS/NZS 5033, 4777, 3000, 3008.1, 5139 and the IEC module/inverter standards (scope only; we don't reproduce the copyrighted text)
- [Network connection authorities](https://wattbench.ai/network-authorities): Official live solar and battery connection guidance for 16 Australian distribution networks; site-specific approvals override general guidance and Wattbench does not cache generic export limits
- [Fault-code finder](https://wattbench.ai/fault-codes): Search every documented code across all brands
- [Explainers hub](https://wattbench.ai/field-guides): All fault libraries and technology explainers
- [Calculators hub](https://wattbench.ai/tools): All interactive field calculators
- [Glossary](https://wattbench.ai/glossary): Solar and electrical terms, defined and fact-checked
- [Ask Watt](https://wattbench.ai/ask): Grounded AI assistant: ask about a code, calculator or standard, answered from Wattbench with the source cited
- [Methodology](https://wattbench.ai/methodology): How the bench works: traceable figures, blanks over guesses, manufacturer-neutral
- [About](https://wattbench.ai/about): What Wattbench is, who it's for, and the Solar Analytica network it belongs to
- [Contact](https://wattbench.ai/contact): Corrections, data licensing, partnerships and media. A real person reads every message
- [Changelog](https://wattbench.ai/changelog): A dated record of what has shipped on the bench
- [Search](https://wattbench.ai/search): Search the full bench

## The network
Wattbench is the applied bench in a wider evidence-first solar network.
- [Solar Analytica](https://solaranalytica.com): Sister site: evidence-first solar market data, indices and projections
- [review.solar](https://review.solar): Sister site: independent product scorecards for panels, batteries and inverters

## Optional
- [Full content](https://wattbench.ai/llms-full.txt): Every explainer, fault code, glossary term and calculator, inlined as plain text
- [Fault code data (JSON)](https://wattbench.ai/fault-codes.json): Open data: every documented fault code, free with attribution
- [Fault code data (CSV)](https://wattbench.ai/fault-codes.csv): The same library as a spreadsheet-friendly download
- [Resource graph (JSON)](https://wattbench.ai/resource-graph.json): Canonical resources, field taxonomy, supported relationships and provenance coverage
- [RSS feed](https://wattbench.ai/feed.xml): New fault libraries, calculators and explainers
- [Sitemap](https://wattbench.ai/sitemap.xml): XML index of every indexable page
- [AI usage policy](https://wattbench.ai/ai.txt): How AI assistants may use this content
- [Security policy](https://wattbench.ai/.well-known/security.txt): How to report a security issue (RFC 9116)