Hypertherm MAX200 Machine Torch Plasma Arc Cutting System - Manual (Page 183)

d-2 MAX200 Instruction Manual
14
APPENDIX D – ELECTROMAGNETIC COMPABILITY (EMC)
EMC INTRODUCTION
This plasma cutting equipment has been
built in compliance with standard EN50199.
To ensure that the equipment works in a
compatible manner with other radio and
electronic systems, the equipment should
be installed and used in accordance with
the information below to achieve electro-
magnetic compatibility.
The limits required by EN50199 may not
be adequate to completely eliminate inter-
ference when the affected equipment is in
close proximity or has a high degree of
sensitivity. In such cases it may be neces-
sary to use other measures to further re-
duce interference.
This plasma equipment should be used
only in an industrial environment. It may be
difficult to ensure electromagnetic com-
patibility in a domestic environment.
INSTALLATION AND USE
The user is responsible for installing and
using the plasma equipment according to
the manufacturer's instructions. If electro-
magnetic disturbances are detected then
it shall be the responsibility of the user to
resolve the situation with the technical
assistance of the manufacturer. In some
cases this remedial action may be as
simple as earthing the cutting circuit, see
Earthing of Workpiece. In other cases it
could involve constructing an electro-
magnetic screen enclosing the power
source and the work complete with asso-
ciated input filters. In all cases electro-
magnetic disturbances must be reduced
to the point where they are no longer
troublesome.
ASSESSMENT OF AREA
Before installing the equipment the user
shall make an assessment of potential
electromagnetic problems in the sur-
rounding area. The following shall be
taken into account:
a. Other supply cables, control cables,
signalling and telephone cables; above,
below and adjacent to the cutting
equipment.
b. Radio and television transmitters and
receivers.
c. Computer and other control equipment.
d. Safety critical equipment, for example
guarding of industrial equipment.
e. Health of the people around, for
example the use of pacemakers and
hearing aids.
f. Equipment used for calibration or
measurement.
g. Immunity of other equipment in the
environment. User shall ensure that other
equipment being used in the environment
is compatible. This may require additional
protection measures.
h. Time of day that cutting or other
activities are to be carried out.
The size of the surrounding area to be
considered will depend on the structure
of the building and other activities that are
taking place. The surrounding area may
extend beyond the boundaries of the
premises.
METHODS OF REDUCING
EMISSIONS
Mains Supply
Cutting equipment should be connected to
the mains supply according to the manu-
facturer's recommendations. If inter-
ference occurs, it may be necessary to
take additional precautions such as filter-
ing of the mains supply. Consideration
should be given to shielding the supply
cable of permanently installed cutting
equipment, in metallic conduit or equiva-
lent. Shielding should be electrically con-
tinuous throughout its length. The shield-
ing should be connected to the cutting
mains supply so that good electrical con-
tact is maintained between the conduit and
the cutting power source enclosure.
Maintenance of Cutting Equipment
The cutting equipment should be
routinely maintained according to the
manufacturer's recommendations. All
access and service doors and covers
should be closed and properly fastened
when the cutting equipment is in oper-
ation. The cutting equipment should not
be modified in any way except for those
changes and adjustments covered in the
manufacturer's instructions. In particular,
the spark gaps of arc striking and stabil-
izing devices should be adjusted and
maintained according to the manu-
facturer's recommendations.
Cutting Cables
The cutting cables should be kept as short
as possible and should be positioned
close together, running at or close to the
floor level.
Equipotential Bonding
Bonding of all metallic components in the
cutting installation and adjacent to it
should be considered. However, metallic
components bonded to the workpiece will
increase the risk that the operator could
receive a shock by touching these metal-
lic components and the electrode at the
same time. The operator should be in-
sulated from all such bonded metallic
components.
Earthing of Workpiece
Where the workpiece is not bonded to
earth for electrical safety, nor connected to
earth because of its size and position, for
example, ship's hull or building steelwork,
a connection bonding the workpiece to
earth may reduce emissions in some, but
not all instances. Care should be taken to
prevent the earthing of the workpiece
increasing the risk of injury to users, or
damage to other electrical equipment.
Where necessary, the connection of the
workpiece to earth should be made by a
direct connection to the workpiece, but
in some countries where direct connection
is not permitted, the bonding should
be achieved by suitable capacitances
selected according to national regulations.
Note. The cutting circuit may or may not be
earthed for safety reasons. Changing the
earthing arrangements should only be
authorized by a person who is competent
to assess whether the changes will in-
crease the risk of injury, for example, by
allowing parallel cutting current return
paths which may damage the earth
circuits of other equipment. Further guid-
ance is given in IEC TC26 (sec)94 and IEC
TC26/108A/CD Arc Welding Equipment
Installation and Use.
Screening and Shielding
Selective screening and shielding of other
cables and equipment in the surrounding
area may alleviate problems of interfer-
ence. Screening of the entire plasma
cutting installation may be considered for
special applications.