Hypertherm HD4070 Rev.1 - Manual (Page 4)

ELECTROMAGNETIC COMPATIBILITY (EMC)
Hypertherm Plasma Systems i
8-06
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 plasma 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