Schneider Electric EOCR-i3BZ Over current and time setting tips, Alert Operation Pattern #3, Hold

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

Alert Operation Pattern (#3)

Do use this function by OL/GR common output.

Running Stage	Normal Operation	Higher than the preset
Starting		Trip
ALo Selection		Alert value
Aux
Flicker		1 Sec
		◀▶
Hold		1 Sec
		◀▶

Fail-safe operation

Fail-Safe

A1-A2 not powered

A1-A2 powered and

under normal operation

A1-A2 powered

and Tripped

ON

OFF

10