Protection Function - Mitsubishi Electric NZ2GN2S1-16D User Manual

8.6

Protection Function

The transistor output module and the I/O combined module (transistor output part) have the overload protection function and
the overheat protection function.
Overload protection function
If the I/O module detects overcurrent, the module performs the current limiting operation (which limits the overcurrent to a
certain value to continue to provide output).
For the overcurrent detection value and the limited current, refer to the overload protection function in the specifications for
each I/O module.
Page 47 Output module
Page 80 I/O combined module
If the load current becomes equal to the overcurrent detection value or lower, the module returns to normal operation.
Overheat protection function
If the I/O module keeps outputting the overcurrent caused by an overload, heat is generated inside the I/O module. If
excessive heat is detected within the I/O module, it turns off the output.
The multiple points at which the overheat protection function operates depend on the I/O module. Refer to the "Overheat
protection function" column in the specifications table for each I/O module.
Page 47 Output module
Page 80 I/O combined module
If the heat descends, the module automatically returns to normal operation.
The overload protection function and the overheat protection function do not protect external devices; they
protect the internal circuit of the I/O module.
An abnormal load may raise the internal temperature of the I/O module, causing deterioration in output
elements and discoloration of the case and the printed-circuit board. Turn off the corresponding output as
soon as a problem on a load is found, and remove the cause.
8 FUNCTIONS
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8.6 Protection Function
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