1MRK 505 353-UEN Section 6
BP-Additions to base documentation
Application Manual 41
Bay protection functions REB500
Table 47 Definite time over and undercurrent protection 51 (PTOC/PTUC)
Function/ Parameter Range/ Value
• Pick-up current
0.2 to 20 I
N
in steps of 0.01 I
N
Delay 0.02 to 60 s in steps of 0.01 s
Reset ratio:
• overcurrent
undercurrent
>94% (for max. function)
<106% (for min. function)
• Max. operating time without delay 60 ms
• Inrush restraint (optional):
• pick-up setting 0.1 I
2h
/I
1h
· Over- and undercurrent detection
· Single or three-phase measurement with detection of the highest, respectively lowest phase current
· 2nd harmonic restraint for high inrush currents
· 4 independent parameter sets
Accuracies Value
Accuracy of the pick-up setting (at f
N
)
±5%
Table 48 Inverse time overcurrent protection 51 (PTOC)
Function/ Parameter Range/ Value
Inverse time characteristic
(acc. to B.S. 142, IEC 60255-3 with extended setting range):
• normal inverse
• very inverse
• extremely inverse
• long time inverse
t = k
1
/ ((I/I
B
)
C
- 1)
• c = 0.02
• c = 1
• c = 2
• c = 1
• or RXIDG characteristic
t = 5.8 - 1.35 x·ln(I/I
B
)
Number of phases
1 or 3
• Base current I
B
0.04 to 2.5 I
N
in steps of 0.01 I
N
Pick-up current I
start
1 to 4 I
B
in steps of 0.01 I
B
Min. time setting t
min
0 to 10 s in steps of 0.1 s
k
1
setting
0.01 to 200 s in steps of 0.01 s
· Single or three-phase measurement with detection of the highest phase current
· 4 independent parameter sets
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