Blocking - ABB REL650 series Technical Manual

1MRK 506 335-UUS A
Voltage
VL1
VL2
VL3
8.1.7.3
Technical manual
The type B curve is described as:
×
TD 480
=
t
æ
Vpickup < -V
× -
ç
32 0.5
è
<
Vpickup
EQUATION1608 V1 EN
The lowest voltage is always used for the inverse time delay integration. The details of the
different inverse time characteristics are shown in section
characteristics".
Figure 137: Voltage used for the inverse time characteristic integration
Trip signal issuing requires that the undervoltage condition continues for at least the user
set time delay. This time delay is set by the parameter t1 and t2 for definite time mode (DT)
and by some special voltage level dependent time curves for the inverse time mode
(TUV). If the pickup condition, with respect to the measured voltage ceases during the
delay time, the corresponding pickup output is reset.

Blocking

It is possible to block Two step undervoltage protection (UV2PTUV ,27) partially or
completely, by binary input signals or by parameter settings, where:
BLOCK:
BLK1:
BLK2:
+
0.055
2.0
ö
÷
ø
blocks all outputs
blocks all pickup and trip outputs related to step 1
blocks all pickup and trip outputs related to step 2
Section 8
Voltage protection
21.3 "Inverse time
IDMT Voltage
Time
ANSI12000186-1-en.vsd
(Equation 74)
297