The measurement control unit (MCU)
What the LEDs mean
Communication status LED (yellow)
This indicates that there is communication between the meter and the UIU.
LED is flashing: data is being received and transmitted between the meter and the UIU.
LED is permanently off: there is no communication between the meter and the UIU.
LED is permanently on: there is a short circuit on the communication cable between the meter
and the UIU.
Power / load status LED (green)
This LED has a dual function - it indicates that the meter is powered and also indicates if the
consumer’s supply is connected.
LED is permanently on: the meter is powered and the consumer’s supply is connected.
LED is flashing: the meter is powered but the consumer’s load is disconnected.
LED is off: the meter is not powered and the consumer has no supply.