TISP61089
DUAL FORWARD-CONDUCTING P-GATE THYRISTORS
PROGRAMMABLE OVERVOLTAGE PROTECTORS
NOVEMBER 1995 - REVISED FEBRUARY 1998
table 2. second-level surge current
GENERATOR
TOTAL
CIRCUIT
RESISTANCE
Ω
OPEN-CIRCUIT
VOLTAGE
V
SHORT-CIRCUIT
CURRENT
A
FICTIVE
SOURCE
RESISTANCE
Ω
IT
A
WAVE SHAPE
2/10
5000
5000
500
420
10
50
52
2x100
2x96
1.2/50, 8/20
(See Text)
4 + 8/conductor
prospective short-circuit current wave shape to be similar to the 1.2/50 open-circuit voltage wave shape. The
TISP61089 will survive the 2x96 A 1.2/50 as its rating is 2x100 A.
Using a 25 Ω series resistor will result in table 2. IT column values of 2x143 and 2x135. The TISP61089 may
fail at these peak current values as they are higher than the TISP61089 ratings.
section 4.5.9 - Intra-building surge testing
These tests use a 2/10 wave shape. As shown in table 3, the peak currents for this test are 2x27 A and 17 A.
The TISP61089 can survive both these levels as its rating is 2x120 A.
table 3. intra-building surge currents
GENERATOR
OPEN-CIRCUIT
VOLTAGE
V
SHORT-CIRCUIT
CURRENT
A
FICTIVE
SOURCE
RESISTANCE
Ω
TOTAL CIRCUIT
RESISTANCE
Ω
IT
A
WAVE SHAPE
2/10
1500
800
100
100
94
15
8
55
48
56
2x27
17
1.2/50, 8/20
(See Text)
1500
4 + 12/conduc-
tor
2x27
800
100
2 + 6
48
17
Compared to TR-NWT-001089, Issue 1, October 1991, GR-1089-CORE, Issue 1, November 1994, the 2/10
alternative of using a CCITT Recommendation K.22 1.2/50-8/20 combination wave generator has been
changed to an IEEE C62.41 1.2/50-8/20 generator. This generator usually has a single output and a fictive
resistance of 2 Ω. The 2/10 generator has fictive output resistances of 15 Ω and 8 Ω. GR-1089-CORE
compensates for this by adding an extra resistances of 12 Ω and 6 Ω in the output of the 1.2/50-8/20
generator. In practice, this extra resistance causes the prospective short-circuit current wave shape to be
similar to the 1.2/50 open-circuit voltage wave shape. The TISP61089 will survive the 2x27 A 1.2/50 as its
rating is 2x100 A.
Using a 25 Ω series resistor will result in table 3. IT column values of 2x38, 24, 2x37 and 24. The TISP61089
will survive these peak current values as they are lower than the TISP61089 ratings.
P R O D U C T
I N F O R M A T I O N
10
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