Basler BE1-50/51B-229, Instruction Manual

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1-4 BE1-50/51B-229 General Information 9252000892 Rev A
Where: T
R
= time to reset in seconds
R = constant for the particular curve
D = time dial setting
M = current in multiples of pickup setting during reset
Figure 1-1. Integrating Reset Characteristic Curve
Instantaneous Overcurrent (50) Element
Setting the INST PICKUP control at the minimum pickup setting places the relay in the most sensitive
state and may be used as a safety setting.
Pickup
Setting Range: 1 to 99 Aac
Setting Increment: 1 Aac
Accuracy:
±
2%,
±
25 mAac at or above 1.0 Aac setting
Dropout
Dropout occurs at 95% of pickup value.
Curve Characteristics
The instantaneous characteristic curves of the BE1-50/51B-229 are similar to those of standard
electromechanical relays. However, the trip time may be slightly longer in applications where the initial
current through the relay is less than 0.4 amperes. This may occur in a very lightly loaded circuit or when
the relay is pro-viding ground protection and is connected to measure neutral current. Figure 1-2 shows
the instantaneous characteristic curves for maximum time to trip.
1
2
−
=
M
RD
T
R