Table of Contents
Advertisement
Note
If operation with capacitive load is not possible, then load points in the underexcited
range can be achieved by changing the polarity of the current transformer connections
(address 210). Thereby the characteristics of the underexcitation protection are mir-
rored around the zero point. It must be noted that the reverse power protection must
be set to OFF (address 3101) as its characteristic is also mirrored from the motor into
the generator range.
Since the protective device shows each load level through the operational measured
values, it is not necessary to approach the underexcitation limit line.
Checking the Direc-
When the polarity of the connections is checked, the direction of the protection func-
tional Function of
tion I>> (Section 2.7) is unambiguously determined by the definition of the reference
the Overcurrent
arrow in the protection device. When the generator produces an active power (opera-
tional measured value P is positive), and address 1108 ACTIVE POWER is set to
Time Protection
Generator, the network is in the forwards direction.
In order to exclude accidental misconnections, it is recommended to carry out a check
with a low load current. Proceed as follows:
• Set the directional high current stage 1301 O/C I>> to Block relay and the
• Increase the load current (ohmic, or ohmic inductive) above the pickup value, and
• Compare the indicated direction with the setpoint (setting value and address 1304
• Reset the pickup value in address 1302 back to the original value and the protec-
3.3.13 Setup of a test fault recording
General
In order to be able to test the stability of the protection during switchon procedures
also, switchon trials can also be carried out at the end. A maximum of information on
protection behaviour is supplied by fault recordings.
Requirement
Along with the capability of storing fault recordings via pickup of the protection func-
tion, the 7UM61 also has the capability of initiating a measured value recording using
the operator control program DIGSI
the latter, event ">Trig.Wave.Cap." must be allocated to a binary input. Triggering
of the recording then occurs, for example, via the binary input when the protection
object is energized.
Such externally started test fault recordings (that is, without a protection pickup) are
handled by the device as normal fault recordings, i.e. for each measurement record a
fault log is opened with its own number, for unequivocal allocation. However, these re-
cordings are not displayed in the fault indication buffer, as they are not fault events.
7UM61 Manual
C53000-G1176-C127-3
pickup value I>> (parameter 1302) to the most sensitive value (= 0.05A with a
rated current of 1A and 0.25 A with a rated current of 5 A).
as soon as the pickup indication (FNo. 1801 to 1803) appear, query the indications
1806 "I>> forward" and 1807 "I>> backward".
Phase Direction). In the standard application with terminal-side current trans-
formers, address 1304 Phase Direction must be set to reverse and indication
"I>> forward" (FNo. 1806) must appear.
tion function in address 1301 O/C I>> to ON.
®
via the serial interface and via binary inputs. For
3.3 Commissioning
289
Advertisement
Table of Contents
