Specifications, Time overcurrent (51) element, Be1-50/51b-237 pickup – Basler Electric BE1-50/51B-237 User Manual
Page 12: Be1-50/51b-238 pickup, Dropout, Characteristic curves, Fixed timing, Reset, Instantaneous overcurrent a (50-a) element, Specifications -2

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BE1-50/51B-237/-238 General Information
9252000899 Rev B
Internal switches provide for selecting system-operating frequencies of 50 or 60 Hz, instantaneous
element delays of 0.0 or 0.1 second, characteristic curve group selection for either GE IAC or ABB type
curves, and instantaneous or integrating reset characteristics. Switch location and description is provided
in Section 2.
Specifications
BE1-50/51B-237 and BE1-50/51B-238 electrical and physical specifications are listed in the following
paragraphs.
Time Overcurrent (51) Element
Setting Range ............................ 0.5 to 15.9 Aac
BE1-50/51B-237 Pickup
Setting Increment ....................... 0.1 Aac
Accuracy .................................... Sum of ±2% and ±25 mAac
Setting Range ............................ 0.1 to 3.18 Aac
BE1-50/51B-238 Pickup
Setting Increment ....................... 0.02 Aac
Accuracy .................................... Sum of ±2% and ±5 mAac
Dropout occurs at 95% of pickup value.
Dropout
Available curve types follow IEEE Standard C37.112 (1996) and emulate standard GE IAC, ABB CO, and
BS142 curves. Appendix A, Characteristic Curves illustrates the available curves and lists the applicable
constants.
Characteristic Curves
Curve Types .............................. Short Inverse, Long Inverse, Definite Time, Moderately Inverse, Inverse,
Very Inverse, Extremely Inverse, BS142 Very Inverse, BS142 Extremely
Inverse, Fixed Time
Time Multiplier ........................... 11 curves for each characteristic
Timing Accuracy ........................ ±1 cycle, ±2%. This accuracy applies to the range of 1.3 to 40 times tap
and is for a given measured multiple of tap.
Setting Range ............................ 0.1 to 9.9 s
Fixed Timing
Setting Increment ....................... 0.1 s
Timing Accuracy ........................ ±1 cycle, ±2% of the time to trip for time dial settings ≥0.1.
Integrating .................................. Simulates the disk reset of electromechanical relays and begins when
the current decreases below 95% of pickup. Appendix A, Characteristic
Curves illustrates the integrating reset characteristic curve and equation.
Reset
Instantaneous ............................ Reset occurs within 16 ms of when the current decreases below 95% of
the pickup level.
Instantaneous Overcurrent A (50-A) Element
Setting Range ............................ 2 to 99 Aac
BE1-50/51B-237 Pickup
Setting increment ....................... 1 Aac
Accuracy .................................... Sum of ±2% and ±25 mAac
Setting Range ............................ 0.4 to 19.8 Aac
BE1-50/51B-238 Pickup
Setting increment ....................... 0.2 Aac
Accuracy .................................... Sum of ±2% and ±5 mAac