Toshiba 6F3B0253 - Manual (Page 53)

6F3B0253
Basic Hardware and Function
51
3. I/O Application Precautions
(3) Over-current protection
The output circuit of the T1-16S does not contain protective fuses. Fuses rated for the
output should be provided by the user.
(4) Output surge protection
Where an inductive load is connected to the output, a relatively high energy transient
voltage will be generated when the relay turns OFF. To prevent the problems caused
by this surge, install a surge absorber in parallel to the inductive load.
Surge absorber:
•
Flywheel diode (for DC output)
Inverse withstand voltage: At least three times that of the power supply
Forward current: Larger than the load current
•
Varistor (for AC output)
The voltage rating is 1.2 times the maximum (peak) voltage of the power supply
•
CR snubber (for DC or AC output)
R: 0.5 to 1
Ω
per volt coil voltage
C: 0.5 to 1
µ
F per ampere of coil current (non-polarity capacitor)
T1
output
PS
Load
Load
Fuse appropriate to
the common current
T1
output
circuit
PS
Load
Surge absorber