• any phase current is lower than CurrUnsymLevel of the highest current in the
three phases.
• the highest phase current is greater than CurrRelLevel of IBase.
If these conditions are true, an unsymmetrical condition is detected. This detection is
enabled to generate a trip after a set time delay tTrip if the detection occurs in the next
200 ms after the circuit breaker has received a command to open trip or close and if the
unbalance persists. The 200 ms limitation is for avoiding unwanted operation during
unsymmetrical load conditions.
The pole discordance protection is informed that a trip or close command has been
given to the circuit breaker through the inputs CLOSECMD (for closing command
information) and OPENCMD (for opening command information). These inputs can
be connected to terminal binary inputs if the information are generated from the field
(that is from auxiliary contacts of the close and open push buttons) or may be software
connected to the outputs of other integrated functions (that is close command from a
control function or a general trip from integrated protections).
8.6.8 Technical data
Table 120: CCRPLD technical data
Function
Range or value Accuracy
Operate value, current
asymmetry level
(0-100) % ± 1.0% of I
r
Reset ratio >95% -
Time delay (0.000-60.000) s ± 0.5% ± 25 ms
8.7 Directional over-/under-power protection
GOPPDOP/GUPPDUP
8.7.1 Functionality
The directional over-/under-power protection GOPPDOP/GUPPDUP can be used
wherever a high/low active, reactive or apparent power protection or alarming is
required. The functions can alternatively be used to check the direction of active or
reactive power flow in the power system. There are a number of applications where
such functionality is needed. Some of them are:
• detection of reversed active power flow
• detection of high reactive power flow
Each function has two steps with definite time delay.
1MRK 502 048-UEN A Section 8
Current protection
231
Technical manual
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