IEC18000247 V1 EN-US
Figure 23: Single-phase pickup factor when ZSCurrSubtrW2 = Off
For phase angle shifts greater than ±60 degrees, actual operation will
happen in one of other two phases where current has not been injected.
• When ZSCurrSubtrW2 = On, this factor will have a value between 1.50 and 1.732 depending
on the actual phase angle shift as shown in Figure 24:
IEC18000248 V1 EN-US
Figure 24: Single-phase pickup factor when ZSCurrSubtrW2 = On
For phase angle shifts greater than ±30 degrees, actual operation will happen in
one of the other two phases where the current has not been injected.
The pickup current is dependent on the actual phase angle shift across the
protected PST.
3. Check that the trip and alarm contacts operate according to the configuration logic.
4. Decrease the current slowly from operate value and note the reset value.
5. Repeat the procedure by injecting current in phases L2 and L3 respectively.
1MRK 504 165-UUS Rev. J Section 11
Testing functionality by secondary injection
Transformer protection RET670 105
Commissioning manual
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