Grounding current transformer - Measured values too low by approx. 50%.
EFR4000IP; EFR4001IP

If the connected current transformers are grounded at higher measuring voltages, the device measures only about half the power. This is due to the design of the measuring inputs.
As a remedy, intermediate transformers with suitable accuracy and power are connected before the measuring inputs of the EFR4001IP, 5/5 A or 5/1 A (e.g. MBS WSK 30, part numbers 30013 or 30211).

 How to check the dropout ratio (up to firmware 0-12)
UFR1001E

The fallback ratio is the quotient between the value at which an overshoot is detected and dAL starts and the value at which dAL stops running if it falls below again before dAL expires.

The component certificate explicitly confirms the fallback ratios <2%. (1.02 for undervoltage/underfrequency; 0.98 for overvoltage/overfrequency).

Nevertheless, the drop-out ratios can be checked as follows:
- Set dAL to a longer time (e.g. 5.00s).
- exceed/fall below limit (e.g. at U< = 0.8 * Un to 0.78 * Un)
- back again just into the good range (in the example to 0.81 * Un)
- wait min. 5.00s (>= set dAL)
If no triggering takes place, the drop-out ratio is <2%.