26
3.2.5 Module installation
(1) Installing modules contiguously
In QAnS 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 open slots between any two modules. If there is an
open slot on the left side of a module with 100/200 VAC rating, the
printed board which contains the hazardous voltage circuit
becomes bare. When it is unavoidable to make an open slot, be
sure to install the blank module (A1SG60).
3.2.6 Grounding
There are two kinds of grounding terminals as shown below. Either
grounding terminal must be used grounded.
Be sure to ground the protective grounding for the safety reasons.
3.2.7 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 intelligent function
module (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 Table 1.
Protective grounding : Maintains the safety of the programmable
controller and improves the noise resistance.
Functional grounding : Impr oves the noise resistance.
Table 1 :Intensive Insulation Withstand Voltage
(Installation Category II, source : IEC664)
Rated voltage of hazardous voltage area Surge withstand voltage (1.2/50 µs)
150 VAC or below 2500 V
300 VAC or below 4000 V
To Next Page
Loading...
