Basler BE1-CDS240, Instruction Manual

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Figure 4-35. Voltage Protection Screen, Overexcitation (24) Tab
The reset rate is determined by the reset dial setting. A setting of 0.0 enables reset to be instantaneous.
Using the inverse squared characteristic, assume a trip time dial setting 2.0 and a pickup multiple of 1.2.
The total time to trip will be 50 seconds. If this exists for 30 seconds before being corrected (60% elapsed
time), what would the total reset time be for a reset dial setting of 5? Based on the reset equation
(Equation 4-15), the calculation will be:
seconds 300 100
50
30
0 . 5 100
      
R
T
R R
T
FST
E
D T
Equation 4-15. Time to Reset
If the overexcitation condition returns prior to total reset (i.e., less than 300 seconds), timing resumes from
that point at the inverse square rate. For example, if this condition recurs after 150 seconds or 50% of the
total reset time, then trip time from the second event will start at 30% instead of 0%, therefore tripping in
70% or the original trip time or 35 seconds. Figure 4-36 illustrates the inverse time delay and reset time.
Figure 4-36. Inverse Time Delay and Reset Time
9365200990 Rev F BE1-CDS240 Protection and Control 4-41