Solar · Error codes · Shenzhen Lux Power Technology Co., Ltd
W021Shenzhen Lux Power Technology Co., Ltd · LXP Hybrid 3-6K (LXP 3.6K/5K Hybrid, HB, MG)
W021 on a Shenzhen Lux Power Technology Co., Ltd LXP Hybrid 3-6K: Leakage current high
Short answer
On a Shenzhen Lux Power Technology Co., Ltd inverter, W021 means: Leakage current high. The inverter stops until the fault clears or is reset. An engineer is needed to fix the cause.
Reviewed 24 September 2026 · 1 source
What it means
The manual says: Leakage current high.
Likely causes:
- Leakage current.
Is it safe?
| Does the inverter stop? | Yes |
|---|---|
| Severity | Fault — clears by itself when the condition goes |
| Engineer needed? | Yes |
The inverter stops until the fault clears or is reset.
Resetting itself: re-tests.
Manual reset: Restart inverter (installer) per manual.
What you can check
- Read the code on the inverter LCD or in the LuxPower monitoring app/web portal and note it. Check the AC isolator and consumer-unit breaker for the inverter are ON. Lux's action for most codes is 'restart inverter, if the error still exists, contact us' - ask your installer to do this unless they have shown you the shutdown/start-up order.
What the engineer will check
- Check for earth leakage; restart.
Who to ask for: MCS PV/battery installer familiar with Lux Power.
Certification: MCS-certified solar PV installer (MIS 3002) or competent electrician (BS 7671 / Part P in England & Wales); DC work only by PV-trained installer.
What you might notice
Sources
- LXP Hybrid Inverter User Manual EN-UM-2.0 (LXP 3K/3.6K/4K/4.6K/5K/6K Hybrid, HB, MG) ↗ · EN-UM-2.0-03/04 · page PDF p.20 (printed pp.35-36) · Reviewed 24 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 24 September 2026