Hypertherm HPR260 Manual Gas Preventive Maintenance Program Rev.5 - Manual (Page 5)

ELECTROMAGNETIC COMPATIBILITY (EMC)
Hypertherm i
6-07
EMC Introduction
Hypertherm’s CE-marked equipment is built in compliance
with standard EN60974-10. The equipment should be
installed and used in accordance with the information
below to achieve electromagnetic compatibility.
The limits required by EN60974-10 may not be adequate
to completely eliminate interference when the affected
equipment is in close proximity or has a high degree of
sensitivity. In such cases it may be necessary to use other
measures to further reduce interference.
This cutting equipment is designed for use only in an
industrial environment.
Installation and use
The user is responsible for installing and using the plasma
equipment according to the manufacturer’s instructions.
If electromagnetic 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 electromagnetic
screen enclosing the power source and the work
complete with associated input filters. In all cases
electromagnetic 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
surrounding 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 must be connected to the mains
supply according to the manufacturer’s recommendations.
If interference occurs, it may be necessary to take
additional precautions such as filtering of the mains supply.
Consideration should be given to shielding the supply
cable of permanently installed cutting equipment, in
metallic conduit or equivalent. Shielding should be
electrically continuous throughout its length. The shielding
should be connected to the cutting mains supply so that
good electrical contact is maintained between the conduit
and the cutting power source enclosure.
Maintenance of cutting equipment
The cutting equipment must 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
operation. 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 stabilizing devices
should be adjusted and maintained according to the
manufacturer’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 metallic components and the
electrode (nozzle for laser heads) at the same time.
The operator should be insulated from all such bonded
metallic components.