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Range
Setting variation
Operating time variation
Harmonic Content
Harmonic content of waveforms
Operating time variation
Auxiliary DC Supply – IEC 60255-11
Allowable superimposed ac component
Allowable breaks/dips in supply (collapse to zero from
nominal voltage)
8.3 Distance Function Reach
Reach Accuracy, ± 5% or 0.1 Ω which ever is greater up to an SIR of 30
Reach Accuracy, ± 10% or 0.1 Ω which ever is greater, from an SIR of 30 to an SIR of 60
Typical characteristics for all fault types are shown in Figure 4
Characteristic Angle Setting ≤ ±3°
Zone Timers (Z1T through Z4T)
≤ ±1% or ±10ms (whichever is greater)
8.4 Departure from Reference Angle
The nominal setting of the relay at angles other than the reference angle depends upon the characteristic shape.
In general terms the impedance setting (Z) at any angle (Φ) can be expressed in terms of the nominal setting (ZN)
at the reference angle (ΦN) as follows,
=
Z
Z
f
(Φ
)
N
Where
f
(Φ
)
is the equation defining the characteristic. Using this method the variation in characteristic shape
can be simply specified in terms of class accuracy and the deviation from the reference angle. At nominal voltage
the variations are listed below.
Circular characteristic
Φ
– Nominal characteristic angle
N
Z
– Nominal impedance setting
N
1
Z
– Measured impedance at nominal angle
N
Φ
=
Φ
±
°
For
10
N
=
Φ
−
Φ
1
Z
Z
*
cos(
N
N
At other angles within the limits 90° ≥
=
Φ
−
Φ
1
Z
Z
*
cos(
N
N
The departure from reference angle is for a three phase balanced condition.
The above variations can also be applied to offset characteristics by transferring the origin.
8.5 Transient overreach
The class index plus an error not exceeding the class index.
©2011 Siemens Protection Devices Limited
Φ
N
±
)
. 0
05
Z
N
Φ
≥ 0°
±
)
0
1 .
Z
N
7SG164 Ohmega 400 Series Performance Specification
47Hz to 52Hz
57Hz to 62Hz
≤ 5%
≤ 5%
Frequencies to 550Hz
≤ 5%
≤ 12% of DC voltage
≤ 20ms
Chapter 5 Page 7 of 13
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