14
•
An ambient temperature that falls below 0
°
or exceeds 55
°
C for the CPU, or
that falls below 0
°
or exceeds 45
°
C for the Programming Console.
•
Abrupt changes in temperature that cause condensation.
•
A relative humidity less than 10% or greater than 90%.
•
Corrosive or flammable gas.
•
Dust, salt, or iron particles.
•
Direct vibration or shock.
•
Direct sunlight.
•
Splashes of water, oil, or chemicals.
2-2-2
Cooling
There are two points to consider in order to ensure that the PC does not
overheat. The first is the clearance between the CPUs and control panel sur-
round them, and the second is the installation of a cooling fan.
Clearance
The CPUs need to have sufficient room between them to allow for I/O wiring,
and additional room to ensure that the wiring does not hamper cooling. The
CPU’s must be mounted close enough so that the length of the Connecting
Cable between any CPU and the Link Adapter does not exceed 4 meters.
Cooling Fan
Ensure adequate ventilation is provided for the PCs. A cooling fan is not al-
ways necessary, but may be needed if the PC is mounted in a warm or en-
closed area or over a source of heat. Although it is best to avoid installing the
PC in a warm area, use a cooling fan or an air conditioner, as shown in the
following illustration, to maintain the ambient temperature within specifica-
tions.
PC
Fan
Control Panel
Louver
2-2-3
Preventing Noise
In order to prevent noise from interfering with the operation of the PC, use
AWG 14 twisted-pair cables (cross-sectional area of at least 2 mm
2
). Do not
mount the PC in a control panel in which high-power equipment is installed
and make sure the point of installation is at least 200 mm away from power
cables, as shown in the following diagram. Ground the panel to which the PC
is mounted.
PC
200 mm min.
200 mm min.
Power lines
Installation
Section 2-2