Control Cabinet; Grounding - Mitsubishi Electric A960GOT User Manual

1 OVERVIEW

1.3.3 Control cabinet

1.3.4 Grounding

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Because the GOT is open type equipment (a device designed to be stored within
another module), be sure to use it only when installed in a control cabinet.
1) Electrical shock prevention
In order to such as the operators from electric shocks, the control box must have
the following functions :
a) The control cabinet must be equipped with a lock so that only skilled or
qualified personnel.
b) The control cabinet must be fitted with advice which automatically stops the
power supply when the cabinet is opened.
2) Dustproof and waterproof features
The control cabinet also provides protection from dust, water and ether
substances. Insufficient ingression protection may lower the insulation withstand
voltage, resulting in insulation destruction. The insulation in our GOT is designed
to cope with the pollution level 2, so use in an environment with pollustion level 2
or better.
Pollution level 1 :
Pollution level 2 :
Pollution level 3 :
Pollution level 4 :
There are two kinds of grounding terminals as shown below. Both terminals must be
grounded.
Be sure to ground the grounding for the safety reasons and EMC Directives.
Protective grounding
Functional grounding
An environment where the air is dry and conductive dust
does not exist.
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 box
equivalent a control room or on the floor of a typical factory.
An environment where conductive dust exits and
conductivity may be generated due to the accumulated
dust.
An environment for a typical factory floor.
Continuous conductivity may occur due to rain, snow, etc.
An outdoor environment.
: Maintains the safety of the GOT and improves the noise
resistance.
: Improves the noise resistance.
MELSEC-GOT
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