ABB REB650 Technical Manual page 140

Section 8
Voltage protection
Voltage
VA
VB
VC
ANSI05000016 V1 EN
Figure 53: Voltage used for the inverse time characteristic integration
134
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 53. The details of the different inverse time characteristics are
shown in section "Inverse time characteristics"
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.
0 035 .
0 035 .
1MRK 505 277-UUS C
(Equation 32)
(Equation 33)
Inverse Time Voltage
Time
en05000016_ansi.vsd
Technical Manual