Mitsubishi A2USCPU(S1), User Manual

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EMC AND LOW VOLTAGE DIRECTIVES 9.
9.2.5 Module installation
(1) Installing modules contiguously
In AnS series programmable controllers, the left side of each I/O module is left open.
When installing an I/O module to the base, do not make any empty slots between any
two modules. If there is an empty slot on the left side of a module with 100/200VAC
rating, the circuit board which contains the hazardous voltage circuit becomes bare.
When it is unavoidable to make an empty slot, be sure to install the blank module
(A1SG60).
When using the A1S5 B(S1) extension base with no power supply, attach the cover
packaged with the extension base to the side of the leftmost module.
9.2.6 Grounding
There are two kinds of ground terminals as shown below. Either ground terminal must be
used grounded.
Be sure to ground the protective grounding for the safety reasons.
9.2.7 External wiring
(1) Module power supply and external power supply
For the remote module which requires 24VDC as module power supply,
the 5/12/24/48VDC I/O module, and the special function module which requires the
external power supply, use the 5/12/24/48VDC circuit which is doubly insulated from
the hazardous voltage circuit or use the power supply whose insulation is reinforced.
(2) External devices
When a device with a hazardous voltage circuit is externally connected to the
programmable controller, use a model whose circuit section of the interface to the
programmable controller is intensively insulated from the hazardous voltage circuit.
(3) Intensive insulation
Intensive insulation refers to the insulation with the dielectric withstand voltage shown
in the following table.
Protective grounding
: Maintains the safety of the programmable controller and
improves the noise resistance.
Functional grounding
: Improves the noise resistance.
Intensive Insulation Withstand Voltage (Installation Category II, source : IEC664)
Rated voltage of hazardous
voltage area
Surge withstand voltage
(1.2/50 s)
150VAC or below 2500V
300VAC or below 4000V