SMA METER CONNECTION BOX - Manual (Page 21)

SMA Solar Technology AG Troubleshooting
Installation Guide METERBOX-IEN110611 21
10 Troubleshooting
Problem Cause Rectification
The "Ready" LED is
continuously off. There is no voltage. Check the supply voltage and
plug-in power supply.
The voltage is too low.
The "Pulse" LED is
continuously on. There is a short circuit in the
S0 terminal. Check wiring.
The "Pulse" LED is
continuously off. No meter pulses are being received
from the energy meter. Check wiring.