Toshiba GR 200 Series, Instruction Manual

Page: 269 / 1563

6F2S1915 (0.46)
GRZ200 (Soft 031 & 032)
- 248 -
conformity to IEC 60255-127:
t(G) = TMS × {[
𝑘
(𝑉 𝑉
𝑠
⁄ )
𝑎
− 1
] + 𝑐}
(2.13-1)
where,
t = operating time (seconds),
V = energizing voltage (voltage),
Vs = pickup voltage setting (voltage), and
TMS = time multiplier setting to adjust a curve
If the user will require a user-programmable (original) curve in the inverse time
characteristic, it is provided when the constants of k, a, c are set, as shown in Table 2.13-2. For
example, the user-programmable (original) curve in the OVS1 element will be acquired when
Original
is set for the scheme switch [
OVS1-Timer
], and when values of respective constants
are set for [
OVS1-k
], [
OVS1-a
], and [
OVS1-C
].
Figure 2.13-2 IDMT characteristic of OVS element
Table 2.13-2 Constant value at each setting of IDMT curve
Set item k a C
IDMT 1 1 0
User-programmable
(Original)
0.00000 – 500.00000
by 0.00001 step
0.00000 – 10.00000
by 0.00001 step
0.00000 – 10.00000
by 0.00001 step
0.100
1.000
10.000
100.000
1000.000
1 1.5 2 2.5 3
Ope
ra
ti
ng
T
im
e
(
s
e
c
s
)
Applied Voltage (x Vs)
Overvoltage Inverse Time Curves
TMS = 1
TMS = 2
TMS = 5
TMS = 10