To Next Page

To Previous Page

comparator in the stub protection function STBPTOC. In a comparator the RMS

values are compared to the set operating current value of the function I>.

If a phase current is larger than the set operating current the signal from the comparator

for this phase is activated. If the fault current remains during the timer delay t, the

TRIP output signal is activated. The function can be blocked by activation of the

BLOCK input.

BLOCK

TRIP

STUB PROTECTION FUNCTION

STIL1

STIL2

STIL3

AND

RELEASE

en05000731.vsd

IEC05000731 V1 EN

Figure 58: Simplified logic diagram for Stub protection

6.8.8 Technical data

Table 78: STBPTOC technical data

Function

Range or value Accuracy

Operating current (1-2500)% of

IBase

± 1.0% of I

at I £ I

± 1.0% of I at I > I

Reset ratio > 95% -

Operate time 20 ms typically at 0 to 2 x I

set

Reset time 30 ms typically at 2 to 0 x I

set

Critical impulse time 10 ms typically at 0 to 2 x I

set

Impulse margin time 15 ms typically -

6.9 Pole discordance protection CCRPLD

Section 6 1MRK 511 287-UEN A

Current protection

136

Technical manual

ABB REC650 User Manual

Other manuals for ABB REC650