Control Panel - Mitsubishi MELSEC-A A2USHCPU-S1 User Manual

9. EMC AND LOW VOLTAGE DIRECTIVES
9.2.4

Control panel

Because the programmable controller is an open device (a device designed to be stored
within another device), be sure to use it after storing in the control panel.
(1)
(2)
* Also, each network remote station needs to be installed inside the control panel. However, the
waterproof type remote station can be installed outside the control panel.
Shock protection
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.
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 pollustion 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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