Blocking - ABB REL650 series Technical Manual

Section 8
Voltage protection
8.2.7.3
304
TD ⋅ 480
t = −
V Vpickup − >
32 ⋅ − 0 5 .
Vpickup >
ANSIEQUATION2287 V2 EN
The type C curve is described as:
TD ⋅ 480
t = +
V Vpickup − >
32 ⋅ − 0 5 .
Vpickup >
ANSIEQUATION2288 V2 EN
The highest phase (or phase-to-phase) voltage is always used for the inverse time delay
integration, see Figure 140. The details of the different inverse time characteristics are
shown in section "Inverse time
Voltage
VA
VB
VC
ANSI05000016 V2 EN
Figure 140: Voltage used for the inverse time characteristic integration
A TRIP requires that the overvoltage 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
selected voltage level dependent time curves for the inverse time mode (TOV). 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 overvoltage protection (OV2PTOV ,59) partially or
completely, by binary input signals where:
0 035 .
0 035 .
characteristics".
1MRK 506 335-UUS A
(Equation 78)
(Equation 79)
IDMT Voltage
Time
ANSI05000016-2-en.vsd
Technical manual