Basler Electric BE1-50/51B-231 - Manual (Page 12)

1-2 BE1-50/51B-231 General Information 9252000895 Rev C
Internal switches provide for selecting instantaneous element delays of 0.0, 0.1, 0.2, or 0.3 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.
Advantages
BE1-50/51B-231 overcurrent relays have many advantages over other overcurrent relays. The primary
advantages are:
• Time characteristics are defined by equations and graphs
• Field selectable time characteristics
• Very low burden extends the linear range of the CTs
• Self powered from the sensed current
• Continuous automatic calibration
BE1-50/51B-231 overcurrent relays 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-231 electrical and physical specifications are listed in the following paragraphs.
Current Sensing Input
Continuous Current.................... 14 Aac
One Second Rating ................... 400 Aac
Time Overcurrent (51) Element
Setting the TIME PICKUP control at the minimum pickup setting places the relay in the most sensitive
state and may be used as a safety setting.
Setting Range ............................ 0.5 to 15.9 Aac
Pickup
Setting Increment ....................... 0.1 Aac
Accuracy .................................... ±2%, ±25 milliamperes at or above 0.5 ampere setting
Dropout occurs at 95% of pickup value.
Dropout
0.0 to 9.9 seconds in 0.1 second steps.
Timing Range
The timing accuracy is the sum of ±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. The measurement of the multiple of tap has an accuracy that
is the sum of ±2%, ±25 milliamperes.
Timing Accuracy
PU setting .................................. 5 amperes
Timing Accuracy Example
Current Applied .......................... 6.5 amperes
+ Multiple Tolerance .................. 6.655 amperes
– Multiple Tolerance .................. 6.345 amperes
Time Curve ................................ E
Time Dial .................................... 5.0
Minimum time dial
using 6.655 amperes ............... 46.5470 seconds
Maximum time dial
using 6.345 amperes ............... 61.3968 seconds
Curve time using 6.5 amperes ... 53.1800 seconds