Toshiba GR200 Series - Page 250

6F2S1914 (0.49)
GRL200 (Soft 033 & 037)
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characteristic; “IEC-VI” for IEC Very inverse; “IEC-EI” for IEC Extremely Inverse; “UK-LTI” for
UK Long Time Inverse; “IEEE-MI” for IEEE Moderately Inverse; “IEEE-VI” for IEEE Very
Inverse; “IEEE-EI” for IEEE Extremely Inverse; “US-CO8” for US CO8 Inverse; “US-CO2” for
US CO2 Short Time Inverse, and “Original” for user-programmable characteristic.)
In the IDMT, the user can also program the characteristic using time-multiplier-setting
(TMS) for the required operate time. For example, when the IEC characteristic is selected, the
user can set the TMS value using the setting [OC1-TMS-IEC] (incidentally, the default value
for the TMS is 1.00). The other TMSs are also available by the [OC1-TMS-UK], [OC1-TMS-
IEEE], [OC1-TMS-US] and [OC1-TMS-ORG].
Table 2.15-3 Constants for IDMT
Curve type
(IEC 60255-151)
Curve Description
k
sec
α
c
sec
A
IEC Normal Inverse (IEC-NI)
0.14
0.02
0
B
IEC Very Inverse (IEC-VI)
13.5
1
0
C
IEC Extremely Inverse (IEC-EI)
80
2
0
-
UK Long Time Inverse (UK-LTI)
120
1
0
D
IEEE Moderately Inverse (IEEE-MI)
0.0515
0.02
0.114
E
IEEE Very Inverse (IEEE-VI)
19.61
2
0.491
F
IEEE Extremely Inverse (IEEE-EI)
28.2
2
0.1217
-
US CO8 inverse (US-CO8)
5.95
2
0.18
-
US CO2 short time inverse (US-CO2)
0.02394
0.02
0.01694
Figure 2.15-5 IDMT characteristic curves