Time Delay - ABB REG650 Technical Manual

1MRK 502 043-UUS B
10.2.7.2
10.2.7.3
10.2.7.4
Technical Manual
preprocessing function, which is discussed in the Basic IED Functions chapter and is
set as a percentage of a global base voltage parameter VBase, SAPTOF (81) is blocked,
and the output BLKDMAGN is issued. All voltage settings are made in percent of the
global parameter VBase. To avoid oscillations of the output PICKUP signal, a
hysteresis has been included.

Time delay

The time delay for SAPTOF (81) is a settable definite time delay, specified by the
setting tDelay.
If the PICKUP condition frequency ceases during the delay time, and is not fulfilled
again within a defined reset time, the PICKUP output is reset.
Blocking
It is possible to block Over frequency protection (SAPTOF, 81) completely, by binary
input signals or by parameter settings, where:
BLOCK: blocks all outputs
If the measured voltage level decreases below the setting of MinValFreqMeas in the
preprocessing function Signal Matrix for analog inputs (SMAI), both the PICKUP and
the TRIP outputs, are blocked.
Design
The design of overfrequency protection SAPTOF (81) is schematically described in
figure 138.
Section 10
Frequency protection
297