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3.2 Requirements for Compliance with Low Voltage Directives
The Low Voltage Directives apply to the electrical equipment operating from 50
to 1000VAC or 75 to 1500VDC; the manufacturer must ensure the adequate
safety of the equipment.
Guidelines for installation and wiring of MELSEC-QnA series programmable
controller are provided in Section 3.2.1 to 3.2.7 for the purpose of compliance
with the EMC Directives.
The guidelines are created based on the requirements of the regulations and
relevant standards, however, they do not guarantee that the machinery
constructed according to them will comply with the Directives.
Therefore, the manufacturer of the machinery must finally determine how to
make it comply with the EMC Directives: if it is actually compliant with the EMC
Directives.
3.2.1 Standard applied for MELSEC-QnA series programmable controller
The standard applied for MELSEC-QnA series programmable controller series
is EN61010-1 safety of devices used in measurement rooms, control rooms, or
laboratories.
For the modules which operate with the rated voltage of 50 VAC/75 VDC or
above, we have developed new models that conform to the above standard.
For the modules which operate with the rated voltage under 50 VAC/75 VDC,
the conventional models can be used, because they are out of the low voltage
directive application range.
3.2.2 Precautions when using the MELSEC-QnA series programmable
controller
Module selection
(1) Power module
For a power module with rated input voltage of 100/200 VAC, select a model in
which the internal part between the first order and second order is intensively
insulated, because it generates hazardous voltage (voltage of 42.4 V or more at
the peak) area.
For a power module with 24 VDC rated input, a conventional model can be used.
(2) I/O module
For I/O module with rated input voltage of 100/200 VAC, select a model in
which the internal area between the first order and second order is
intensively insulated, because it has hazardous voltage area.
For I/O module with 24 VDC rated input, a conventional model can be used.
(3) CPU module, memory cassette, base unit
Conventional models can be used for these modules, because they only
have a 5 VDC circuit inside.
(4) Special function module
Conventional models can be used for the special modules including analog
module, network module, and positioning module, because the rated voltage
is 24 VDC or smaller.
(5) Display device
Use the CE-marked product.
