Release 7/2009 Ver. 1.0
Technical Manual: GS-120 Light Curtain Systems
TAPESWITCH CORPORATION
Phone: 631-630-0442
100 Schmitt Boulevard
13
Fax: 631-630-0454
Farmingdale, New York 11735
www.tapeswitch.com
3.0
INSTALLATION
3.1
GENERAL
WARNING
Tapeswitch GS-120 systems are designed to
protect operators working at or near
dangerous machinery. They can only perform
this function if they are correctly fitted and
interfaced to a suitable machine. Those
persons responsible for the machine must
ensure that all persons involved in the
installation of the photo-electric safety
system have the necessary knowledge,
training and experience and that they are fully
aware of all laws, rules, regulations and codes
of practice pertaining to their task.
The attention of the installer is drawn to following
general requirements for the installation of a GS-120
system:
(a)
The dangerous motion of the machine must be
electrically controllable.
(b)
The machine response/stopping performance must
be adequate and consistent.
(c)
It must be possible to stop the dangerous motion of
the machine at any point in its operation, in any
operating mode.
(d)
The control system as a whole must be designed
and constructed to provide the appropriate category of
safety integrity as defined in EN954-1 'Safety of
machinery: Principles for the design of safety related
control systems'. The appropriate category should be as
prescribed in the relevant C type EN standard for the
type of machine concerned. In the absence of such a
standard the appropriate category of safety integrity
should be determined by performing a risk assessment
as described in EN1050 'Safety of machinery: Risk
assessment
(e)
Steps must be taken to prevent access to the
dangerous parts of the machine from any direction not
covered by the photo-electric curtain. Such steps could
include fixed or interlocking fences or screens,
additional photo-electric devices or pressure sensitive
mats. Similar steps should be taken to prevent a person
from standing between the curtain and the dangerous
parts of the machine.
(f)
No devices other than those specified in this manual
should be connected to the internally-generated power
supply of the system.
(g)
After installation, the machine/guard system must be
commissioned in accordance with the requirements of
section 5.1.1 of this manual.
(h)
Any covers removed during installation must be
replaced as soon as possible.
(i)
At power on, after a power interruption or after the
curtain has been actuated, it must not be possible for
the machine to start (or restart) until a manual control
has been operated. This is known as “start/restart
interlock”. The GS-120 can provide this function, but if it
is not installed, it must be provided elsewhere within the
safety system
(j)
To avoid nuisance tripping, if a fluorescent lamp with
an electronic ballast is located within 5 feet (1.5 meters)
of the receiver unit, it must be outside of a 20º field of
view from the receiver unit (±10º about the center line).
If this is not practical, a 60 Hz fluorescent light fixture
should be used.
3.2
MECHANICAL INSTALLATION
3.2.1
GENERAL CONSIDERATIONS
ANSI B11.19-1990 gives guidance on the dimensions
and positioning of photo-electric safety devices fitted to
industrial machines. The main considerations are
described below and are illustrated in
Figure 8
.
(a)
The appropriate protected height must be selected.
The curtain must be of sufficient height such that access
to the dangerous parts, from the direction of approach of
the operator, is only possible by obstructing the curtain
taking into account all possible operator positions.
(b)
The correct minimum separation distance must be
observed. The curtain must be mounted in the correct
position in relation to the dangerous parts of the
machine to take account of the stopping performance of
the machine, the curtain format used and the detection
capability of the curtain.
(c)
Steps must be taken to prevent access to the
dangerous parts from any direction not covered by the
curtain and to prevent an operator from standing
between the curtain and the dangerous parts without
obstructing the curtain. Additional mechanical guarding
will usually be necessary to achieve this.
