Toshiba Programmable Controller PROSEC T3 - Manual (Page 63)

3. Precautions for I/O Module
3.4
Precautions for AC
output modules
(1) The AC output module (AC363, AC364) has a built-in fuse of 6A
per common. For a load short-circuit, fusing will protect the
triacs. However, in this case, semiconductor devices may be
damaged to some extent. Therefore, take measures to prevent
it.
in the case of fusing, or when the external power Is not supplied,
the LED {FL, FH) on the front of the module will light.
(2) If a capacitive load is connected, rush current will flow when the
output is changed to ON. Take necessary measures to suppress
this rush current at a value lower than the allowable limit of the
module.
Allowable inrush current :
AC363 ... 20 A/20 ms (point), 40 A/20 ms (common)
AC364 ... 20 A/20 ms (point and common)
(3) If an inductive load is connected, transient overvoltage will be
generated at the output is changed to OFF. To prevent
malfunction caused by this surge voltage, a CR snubber circuit is
installed in the AC output module. However, to prevent the
problem for other signal systems, install a surge absorption
element in parallel with the inductive load (install a surge
absorption element as near as possible to the inductive load).
Output module H---------H Surge absorption eiement
Surge absorption element:
• Varistor (for the voltage clamp)
Bi-directional overvoltage absorption element
with a rated voltage of approx. 1.2 times of the
max. voltage (peak voltage)
• Snubber (CR) circuit (for high-frequency attenuation)
R (Q)=DC resistance value of the load
oHi—o—o c ( m F)* —JL (I ■-peak value of load
10 20 current in ordinary time)
(4) Because the AC output module does not have a zero-cross
function, the OFF->ON occurs regardless of the load voltage
phases. However, the ON->OFF change occurs when toad
current is near zero. Check this point in load response.
User's manual - Hardware
55