Toshiba T2N - Manual (Page 71)

3.Application Precautions for I/O Modules
56 PROSEC T2N
(1) Over-Current Protection Coordination
One 2A fuse per 4 output points is mounted in the triac output module.
Although, taking account of protecting elements by the fuse blowing even
in load short circuits, when the fuse blows the semiconductors are
subjected to considerable damage. Therefore, take care in handling and
wiring so that short circuits will not occur.
(2) Output Surge Protection
Triac
output
module
L
Surge absorption element
A suitable surge absorption element should be selected according to the
application.
1. Varistor (for voltage
clamping)
(peak) voltage
2. Snubber (CR) circuit
(for high-frequency
attenuation)
Rated voltage about 1.2 times
the maximum power supply
R : 0.5-1
Ω
per 1V coil voltage
C : 0.5-1
µ
F per 1A coil
current
(Non-polar capacitor)
(1) It is necessary to supply a +24V power supply to the internal control circuit
of the relay output module. Therefore, connect a 24Vdc + 10% power
supply between the + and - terminals.
(2) No overload protection fuse is built into the relay output module.
Therefore, always install a fuse suited to the current capacity.
12-point relay output module
Fuse
(3) Output Surge Protection
The installation of a surge absorption element for the induced load, as
described in the paragraphs on the transistor output module and the triac
output module, is recommended.
Please note that, if it is
not protected with a
fuse, the module
pattern will burn out
when there is a load
short-circuit.
NOTE
3.3
Triac Output Module
Application Precautions
3.4
Relay Output Module
Application Precautions