- EV charging
- EV charger
102
Wallbox 102: an internal relay was detected closed when it should have been open
Risk level
High
Professional inspection is recommended.
Urgency
Immediate
Quick answer
102 means an internal relay was detected closed when it should have been open in the cited charger family. The deciding observation is whether the relay-protection code returns after the one official power cycle with the vehicle disconnected. Do not infer a failed part from the code alone.
Safety first
Stop and check this first
- Smoke, burning smell, sparks, water, visible damage, abnormal heat or repeated protective-device trips means stay clear and leave charging disabled. Never open the charger, panel or connector and never probe voltage yourself.
Safe checks you can perform
- Capture the exact charger, vehicle and pattern
- Run the one deciding check
- Use recurrence as the stop point
Leave these tasks to a qualified professional
- Do not attempt this professional task: Measured handoff for 102
What a technician must be able to justify
A technician is coming
These are the steps they must carry out and show you. Tick them as they work: if steps are skipped, do not accept a part swap.
These are not instructions for opening or handling the equipment yourself. They are the checks that should support a technical conclusion.
Measured handoff for 102
What they doVerify isolation, relay/contactor command and welded-contact state under the exact model procedure before deciding between charger repair and replacement.
Before accepting a part or repair
Nothing has been shown yet. Do not accept a part swap based on the code alone.
Checks and evidence, step by step
Follow the documented order. An error code identifies the affected system, but it does not prove by itself which part has failed.
- 1
Capture the exact charger, vehicle and pattern
No special tools
Procedure
Photograph 102 and record the Wallbox model, part/serial number, vehicle model, cable used, charge stage and approximate time. Do not clear the event before those facts are saved.
Smoke, burning smell, sparks, water, visible damage, abnormal heat or repeated protective-device trips means stay clear and leave charging disabled. Never open the charger, panel or connector and never probe voltage yourself.
Evidence: Understanding Wallbox app Error Codes and How to Resolve Them
- 2
Run the one deciding check
No special tools
Procedure
Disconnect the vehicle. If the installation’s labelled breaker is safely accessible, perform the single Wallbox-documented power cycle, let the charger restart, reconnect and restore once. Record whether the relay-protection code returns after the one official power cycle with the vehicle disconnected. Change one condition only.
Smoke, burning smell, sparks, water, visible damage, abnormal heat or repeated protective-device trips means stay clear and leave charging disabled. Never open the charger, panel or connector and never probe voltage yourself.
Evidence: Understanding Wallbox app Error Codes and How to Resolve Them
- 3
Use recurrence as the stop point
No special tools
Procedure
If 102 stays absent, the relay completed its protected opening sequence on the controlled retry; monitor rather than ordering a relay. A returning 102 is a stop condition: leave the vehicle disconnected and do not keep cycling power or open the enclosure.
Smoke, burning smell, sparks, water, visible damage, abnormal heat or repeated protective-device trips means stay clear and leave charging disabled. Never open the charger, panel or connector and never probe voltage yourself.
Evidence: Understanding Wallbox app Error Codes and How to Resolve Them
Where this code applies
A code is meaningful only inside the right product and version context.
Primary scope
- System
- EV charging
- Brand
- Wallbox
- Product type
- EV charger
Known code variants
- 102 Elaborazione
- 102 Procesando
- 102 Processing
- 102 Traitement
- 102 Verarbeitung
- cargador Wallbox 102
- caricatore Wallbox 102
- chargeur Wallbox 102
- code Wallbox 102
- codice Wallbox 102
- código Wallbox 102
- erreur Wallbox 102
- error Wallbox 102
- errore Wallbox 102
- événement Fronius 102
- événement SMA 102
- evento Fronius 102
- evento SMA 102
- Fronius Ereignis 102
- Fronius event 102
- Fronius inverter 102
- Fronius Symo / Eco 102
- Fronius Wechselrichter 102
- HTTP 102
- HTTP status 102
- inversor Fronius 102
- inversor SMA 102
- inverter Fronius 102
- inverter SMA 102
- onduleur Fronius 102
- onduleur SMA 102
- SMA Ereignis 102
- SMA event 102
- SMA inverter 102
- SMA Wechselrichter 102
- Sunny Tripower X 102
- Wallbox app code 102
- Wallbox charger 102
- Wallbox error 102
- Wallbox Fehler 102
- Wallbox Fehlercode 102
- Wallbox Ladegerät 102
What it means
Wallbox’s official documentation defines 102 as an internal relay was detected closed when it should have been open. That is the protection or controller state, not a universal component diagnosis. If 102 stays absent, the relay completed its protected opening sequence on the controlled retry; monitor rather than ordering a relay. A returning 102 is a stop condition: leave the vehicle disconnected and do not keep cycling power or open the enclosure.
Warnings and stop conditions
- Highsource verified
Smoke, burning smell, sparks, water, visible damage, abnormal heat or repeated protective-device trips means stay clear and leave charging disabled. Never open the charger, panel or connector and never probe voltage yourself.
Evidence: Understanding Wallbox app Error Codes and How to Resolve Them
Symptoms and causes
Probable causes · in order
- What the manufacturer code establishesConfirmed
Wallbox documents 102 as a state in which an internal relay was detected closed when it should have been open. Keep this meaning scoped to the cited charger family and exact light/code pattern.
Evidence: Understanding Wallbox app Error Codes and How to Resolve Them
- What the result changes — and what it does not provePossible
If 102 stays absent, the relay completed its protected opening sequence on the controlled retry; monitor rather than ordering a relay. A returning 102 is a stop condition: leave the vehicle disconnected and do not keep cycling power or open the enclosure.
Evidence: Understanding Wallbox app Error Codes and How to Resolve Them
Virtual technician
Does 102 still appear after these checks?
Answer a few questions to narrow down the likely cause and the safest next action. Guidance only - it never replaces a professional.
Sources and technical references
- 1
Understanding Wallbox app Error Codes and How to Resolve Them
Wallbox · 2025 · official_doc
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