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3.2.4 Control panel
Because the programmable controller is an open device (a device designed to be
stored within another module), be sure to use it after storing in the control panel.
(1) Electrical shock prevention
In order to prevent persons who are not familiar with the electric facility such
as the operators from electric shocks, the control panel must have the
following functions:
(a) The control panel must be equipped with a lock so that only the personnel
who has studied about the electric facility and have enough knowledge
can open it.
(b) The control panel must have a structure which automatically stops the
power supply when the box is opened.
(c) For electric shock protection, use IP20 or greater control panel.
(2) Dustproof and waterproof features
The control panel also has the dustproof and waterproof functions. Insufficient
dustproof and waterproof features lower the insulation withstand voltage,
resulting in insulation destruction. The insulation in our programmable
controller is designed to cope with the pollution level 2, so use in an
environment with pollution level 2 or below.
Pollution level 1: An environment where the air is dry and conductive dust
does not exist.
Pollution level 2: An environment where conductive dust
does not usually exist, but occasional temporary
conductivity occurs due to the accumulated dust. Generally,
this is the level for inside the control panel equivalent to
IP54 in a control room or on the floor of a typical factory.
Pollution level 3: An environment where conductive dust exits and
conductivity may be generated due to the accumulated dust.
An environment for a typical factory floor.
Pollution level 4: Continuous conductivity may occur due to rain, snow, etc.
An outdoor environment.
As shown above, the programmable controller can realize the pollution level 2
when stored in a control panel equivalent to IP54.
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