TISP61089A
DUAL FORWARD-CONDUCTING P-GATE THYRISTORS
PROGRAMMABLE OVERVOLTAGE PROTECTORS
JUNE 1999
Using a 25 Ω series resistor will result in table 5. ITM column values of 2x24, 2x7.7, 2x5.7, 2x11, 2x0.47, 2x1.4
and 2x2.9. The TISP61089A will probably fail for a peak current level of 2x24 A and the series current limiting
element must operate in under 0.1 s to prevent exceeding the TISP61089A package limit. For 2x7.7 A, the
series current limiting element must operate within 0.35 s for TISP61089A survival.
section 4.5.15 - second-level power fault testing with wiring simulator
The purpose of this test is to ensure that the telephone cable does not become a hazard due to excessive
current. A series fuse, type MDQ 1-6/10A, simulates the safe current levels of a telephone cable. If this fuse
opens the equipment fails the test. For the equipment to pass, the equipment series overcurrent element must
reduce the current to below the MDQ 1-6/10A fusing level to prevent the simulator operating. The a.c. test
voltage can range from zero to 600 V, which gives a maximum conductor current of 10 A. Table 6 shows the
simulator fusing times for three current levels.
table 6. second-level power fault currents with MDQ 1-6/10A fuse
SHORT-
CIRCUIT
CURRENT
A
TOTAL
CIRCUIT
RESISTANCE
Ω
TIME
TO
OPEN
s
A.C.
OPEN-CIRCUIT
SOURCE
RESISTANCE
Ω
ITRMS
A
ITM
A
DURATION RMS VOLTAGE
s
V
1000
1000
1000
100
300
600
5
20
20
20
60
60
60
1.7
5.0
10
2.4
7.1
14
∞
15
30
30
0.7
Using a 25 Ω series resistor will result in table 6. ITM column values of 2x3.1, 2x9.4 and 2x19. Simulator
operating times will be ∞, 12 s and 0.4 s respectively
For the equipment to pass this test, the TISP61089A series current limiting element must operate before the
MDQ 1-6/10A fusing times shown in table 7.
table 7. operating times of MDQ 1-6/10A fuse
TIME TO
OPERATE
s
IRMS
A
0.2
0.5
1
17
12
9
5
7
10
6.8
2.5
1000
overcurrent protection
To meet ‘1089, the overcurrent protection must be coordinated with the requirements of sections 4.5.7, 4.5.8,
4.5.9, 4.5.12, 4.5.13, 4.5.15 and the TISP61089A. The overcurrent protection must not fail in the first level
tests of sections 4.5.7, 4.5.9 and 4.5.12. Recoverable overcurrent protectors (e.g. Positive Temperature
Coefficient Resistors) may operate during first level testing, but normal equipment working must be restored
P R O D U C T
I N F O R M A T I O N
12
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