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EOCR-i3BZ/iFBZ/3BZ2/FBZ2
EOCR-i3BZ / iFBZ : Intelligent Digital Over-Current, Earth Fault Relay with built-in ZCT,
EOCR-3BZ2 / FBZ2 : Economic Digital Over-Current, Earth Fault Relay with built-in ZCT
Over current and time setting tips
●Over current
Setting tips in definite TCC mode
1. Over current threshold (OC) :
- Set the OC at the rating current of a motor. To protect machine together, it is recommended to set at 110~120% of the actual normal operating
current.
2. Starting delay time (D-time)
- Set an expected start-up time to reach the normal current of load. If you do not know it, set to 15sec at first and start-up the motor to measure the
time to reach the normal operation current by monitoring the displayed current and then set the time at 2 sec longer than the time measured. For
a Y-D start, it’s better to set time 2 sec longer than the preset time of the Y- change timer.
3. Operation time (O-time) : Set the trip delay time which activates and counts down under a fault condition.
Configuration tips when Inverse or Thermal Inverse characteristic is necessary
1. Overcurrent threshold (oc) :
- This value is the basic current and from the point of 105% of oc, the inverse curve starts. Usually oc is set to the rated current of the motor.
2. Starting delay time (D-time)
- Usually this value is set to zero. With zero D-time and Inverse is selected, first the cold curve is applied until the load current drops down the oc
value, and then the hot curve is applied.
- But if the user wants fast trip with very high current during starting, set D-time other than zero. With non-zero D-time, the enabled STALL funtion
detects very high current immediately after the D-time elapsed.
- If the Inverse is selected, and D-time is non-zero, the Inverse function is blocked during starting, and the hot curve is applied after D-time elapsed.
- If Thermal Inverse is selected, it detects overcurrent regardless of D-time. That is, thermal inverse is activated during motor starting as well as
motor running.
3. Operation time (O-time) :
- When Inverse or Thermal Inverse is selected, O-time setting determines the trip class. nEOCR supports trip class from 1 to 30. Refer to the
graphical representation of Inverse or Thermal Inverse to check trip time.
Caution : Do not use any External CT
Aux
““A””
Flicker
““F””
Hold
““H””
Normal OperationStarting
Running Stage
ALo Selection
Higher than the preset
Alert value Trip
Alert Operation Pattern (#3)
Do use this function by OL/GR common output.
ON
OFF
Fail-safe operation
Fail-Safe A1-A2 not powered A1-A2 powered and A1-A2 powered
under normal operation and Tripped
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1 Sec
1 Sec