Table of Contents
Advertisement
Functions
Power system and switchgear data − Block 01
5.3
5.3.1
Function description
Rated frequency
Minimum TRIP
command duration
Lockout function
5-14
Note:
If the protection is operated from a personal computer using the DIGSI communication
software, the test addresses are identified by a four-digit number. This number will be
stated in brackets in the section below.
The 7SS601 measuring system requires some basic data of the power system and the
switchgear so that it can match its functions to these data and to its application.
These data are found in block 32:(5 6<67'$7 and in the switchgear data.
The parameter )5(4 () is used to set the rated system frequency.
The parameter for the minimum TRIP command duration 7753 () ensures
that all connected circuit breakers are reliably tripped as required.
The minimum TRIP command duration can also prevent damage to the TRIP com-
mand contacts of the protection system, which could occur if these contacts were
opened before the auxiliary contacts of the circuit breaker(s) have interrupted the flow
of current through the trip coil. With the parameter 775,3 () the minimum
duration of the TRIP command can be extended long enough to ensure that the flow
of current through the trip coil of the circuit breaker is reliably interrupted.
The parameter /2XW () causes the TRIP command to be memorized until
it is manually reset. A TRIP command that is memorized by the lockout function is not
even reset by an auxiliary power outage; it drops off, however, for as long as the
auxiliary voltage failure persists, as it has no supply voltage.
Logic diagram of the lockout function
Figure 5-16
> -
7SS60 Manual
E50417-G1176-C132-A2
Advertisement
Table of Contents
Troubleshooting
