DEMA CPM 310 G User Manual page 210

Technical Characteristics
2.2 Earth Overcurrent Protection [ANSI 50N/51N] (Continued)
Pick-up Current
Current Reset Ratio (Hysteresis)
Instantaneous Trip Time
Drop-out Time
Trip Time Delays for Earth Thresholds
Reset Time Delays for Earth Thresholds Reset delay ranges for earth fault protection is the same with those for phase fault
2.3 Thermal Overload Protection [ANSI 49]
Measurement Technique
Threshold Setting Range
Thermal Constant Setting Range
Thermal Trip Level Multiplier (k) Setting
Range
Thermal Trip Level Setting Range
Thermal Alarm Level Setting Range
2.4 Broken Conductor Detection [%(I2/I1)>]
Measurement Technique
%(I /I )> Setting Range
2 1
Tripping Delay Setting Range
2.5 Negative Sequence Overcurrent Protection (I2>) [ANSI 46]
Measurement Technique
Threshold Setting Range
Thresholds and Setting Ranges
Pick-up Current
Current Reset Ratio (Hysteresis)
Tripping Delay Setting Range
Resetting Delay Setting Range
2.6 Undercurrent Protection (I<) [ANSI 37]
Measurement Technique
Threshold Setting Range
Tripping Delay Setting Range
Triggering Condition
Current Reset Ratio (Hysteresis)
Pick-up Current
For all threshold values: over 1.05 times the set value.
~%95
~35 ms
~40 ms
Tripping delay ranges for earth fault protection is the same with those for phase
fault protection. DMT and IDMT characteristics available.
protection. DMT and IDMT characteristics available.
RMS current.
I > = (0.1-3.2) I , in steps of 0.01 I
Θ
n
T : (1-200) min, in steps of 1 min.
e
k : 1-1.5, in steps of 0.01.
Trip Θ : %(50-200), in steps of: %1.
Alarm Θ : %(50-200), in steps of: %1.
%(I /I )> where I is fundamental harmonics of positive sequence and I
2 1 1
fundamental harmonics of negative sequence current.
%(20-100), in steps of %1.
(1-14,400) s, in steps of 1 s.
Fundamental harmonic.
(0.1-40) I
n
There are 2 independent thresholds available for negative sequence overcurrent
protection function.
I > = (0.1-40) I , in steps of 0.01 I
2 n
I >> = (0.1-40) I , in steps of 0.01 I
2 n
~1.05 I
s
~%95
The range is the same with phase overcurrent protections'.
The range is the same with phase overcurrent protections'.
Fundamental harmonic.
I< = (0.02-1.0) I , in steps of 0.01 I
n
tI< = (0.01-150) s, in steps of 0.01 s.
Current measurement below the set level while 52a input is active.
~ %105
~ I<
- 210 -
.
n
n.
n.
n.
is
2