Mitsubishi Electric MELSEC-Q Series User Manual page 61

(2) Dustproof and waterproof features
The control box 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
Pollution level 2: An environment where conductive dust does not
Pollution level 3: An environment where conductive dust exits and
Pollution level 4: Continuous conductivity may occur due to rain,
As shown above, the programmable controller can realize the
pollution level 2 when stored in a control panel equivalent to IP54.
conductive dust does not exist.
usually exist, but occasional temporary
conductivity occurs due to the accumulated dust.
Generally, this is the level for inside the control
box equivalent to IP54 in a control room or on the
floor of a typical factory.
conductivity may be generated due to the
accumulated dust.
An environment for a typical factory floor.
snow, etc. An outdoor environment.
27