Shanghai Hanshi Electric Agent EOCR Protector Warm Reminder;Basis for determining the calibration requirements of EOCR protectors;

‌Time cycle trigger‌
Suggested regular calibration cycle ≤ 12 months (shortened to 6 months in heavy industrial environments)If the calibration is not performed within the specified period, the calibration process should be initiated even if there are no abnormalities.

‌Parameter display exception‌

The deviation between the displayed current/voltage value and the measured value of the standard instrument exceeds ± 1%

The output of the 4-20mA transmitter is inconsistent with the values collected by the PLC/DCS system

The three-phase voltage imbalance rate (Ub) exceeds the set threshold (such as 20%)

‌Protection function failure‌

When simulating overload/undervoltage faults, the protector action is delayed or not activated (error should be<2%)

The self-test function (TEST) cannot trigger the contact state change normally

‌Environmental or equipment changes‌

After replacing the current transformer (CT) or adjusting the transformer ratio

Significant changes in motor load characteristics (such as fan to pump loads)

Strong electromagnetic interference or abnormal temperature and humidity in the installation environment

‌Fault record prompt‌
If the protector displays "EPROM ERROR" or records similar faults multiple times (such as frequent undercurrent alarms), priority should be given to calibrating the parameters

Verification method before calibration

‌dynamic testingSimulate locked rotor (3-8 times rated current) to verify SC/LC protection response

‌comparative verificationSynchronize recording with the display value of the protector using a 0.5 level standard table

‌Communication verificationRead whether the parameters are consistent with the local settings through Modbus

Note: Before calibration, disconnect the load power supply and save the parameters to non-volatile memory