Why does my Lux Power backup (EPS) switch off?
Short answer
Lux inverters show W028 'UPS Over Load' when backed-up circuits draw more than the inverter can supply, and E012 'UPS short circuit' for a short on the EPS output. Switch off big appliances on backed-up circuits during a power cut. A short circuit needs an electrician to check the EPS wiring before reuse. Checked 24 September 2026.
Last checked 24 September 2026 · 1 source
What does this mean?
E020 UPS connection fault: EPS and AC connections mixed up Battery must be charged and communicating (W000/W026)
What should I do first?
Record the code and current battery state before changing settings. Follow only the owner-safe reset steps in the manual.
When do I need an engineer?
Use an installer or manufacturer support route if the fault returns, involves isolation or protection, or the manual does not give an owner reset.
What to do next
If the system is hot, smoking, damaged or making unusual electrical noises, move away from it and follow the manufacturer emergency guidance.
Sources
Last checked: 24 September 2026