31
Condition monitoring functions
—
Table 47. 52CM technical data
Characteristic
Value
Current measuring accuracy
±1.5% or ±0.002 x I
n
(at currents in the range of 0.1 to 10 x I
n
)
±5.0%
(at currents in the range of 0.1 to 40 x I
n
)
Operate time accuracy
±1.0% of the set value or ±20 ms
Travelling time measurement
+10 ms / -0 ms
—
Table 48. Fuse failure/Loss-of potential technical data
Characteristic
Value
Trip time
1)
NPS function:
V
Fault
= 1.1 x set Neg Seq
voltage Lev
V
Fault
= 5.0 x set Neg Seq
voltage Lev
< 33 ms
< 18 ms
Delta function:
∆U = 1.1 x set Voltage change rate
∆U = 2.0 x set Voltage change rate
<30 ms
<24 ms
1)
Includes the delay of the signal output contact, f
n
= 60 Hz, fault voltage with nominal frequency injected from ran
-
dom phase angle, results based on statistical distribution of 1000 measurements
1)
Zero sequence voltage before fault = 0.0 x Vn, fn = 60 Hz, zero sequence voltage with nominal frequency in
-
jected from random phase angle, results based on statistical distribution of 1000 measurements
2)
Includes the delay of the signal output contact
—
Table 49. 59N technical data
Characteristic
Value
Operation accuracy
Depending on the frequency of the current measured: f
n
±2Hz
±1.5% of the set value or ±0.002 x V
n
Pickup time
1) 2)
V
Fault
= 1.1 x set Pickup value
Minimum
Typical
Maximum
29 ms
31 ms
32 ms
Reset time
< 40 ms
Reset ratio
Typical 0.96
Retardation time
< 35 ms
Trip time accuracy in definite time mode
±1.0% of the set value or ±20 ms
Suppression of harmonics
DFT: -50dB at f = n x f
n
, where n = 2, 3, 4, 5,…-
