Basler Electric BE1-50/51B-241 - Manual (Page 10)

2 9252000792 Rev D
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Field selectable characteristic curve selection similar to GE IAC or ABB/Westinghouse CO/COM
type curves
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Field selectable instantaneous or integrating reset
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Field selectable 50 or 60 Hz operation
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Field selectable 0.0 or 0.1 second, fixed, instantaneous delay
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
Westinghouse CO/COM type curves, and instantaneous or integrating reset characteristics. Switch
locations and descriptions are provided in the Controls and Indicators chapter.
Advantages
The BE1-50/51B-241 overcurrent relay has many advantages over other overcurrent relays. The primary
advantages are:
•
Time characteristics are defined by equations and graphs
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Field selectable time characteristics
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Very low burden extends the linear range of the CTs
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Self-powered from the sensed current
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Continuous automatic calibration
The BE1-50/51B-241 overcurrent relay may be tested without removing the relay from the case. Shorting
contacts are provided for all current inputs when the connection plugs or relay chassis is removed from
the relay case.
Specifications
BE1-50/51B-241 electrical and physical specifications are listed in the following paragraphs.
Time Overcurrent (51) Element
Pickup
Setting Range:
0.5 to 15.9 Aac
Setting Increment: 0.1 Aac
Accuracy: Sum of
±2% and ±25 mAac
Dropout
Dropout occurs at 95% of pickup value.
Characteristic Curves
Available curve types follow IEEE Standard C37.112 (1996) and emulate standard GE IAC,
Westinghouse CO/COM, and BS142 curves. The Characteristic Curves chapter illustrates the available
curves and lists the applicable constants.
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.
Fixed Timing
Setting Range:
0.1 to 9.9 s
Setting Increment: 0.1 s
Timing Accuracy:
±1 cycle, ±2% of the time to trip for time dial settings ≥0.1
General Information BE1-50/51B-241