Keba KeTop T100, User Manual, Page: 140 / 163

The safety gain is that, in the case of inactive or unassigned equipment, no
danger of confusion is presented to third parties in respect of functional emer-
gency stop buttons.
14.2.9.3 Temporary plug-in handheld terminals: Stop button
Some cabled equipment is provided with a quick-release connector (e.g. bay-
onet) that makes it possible to plug in and unplug the handheld terminal quickly
and ergonomically whilst the machine is in operation. Such handheld terminal’s
are provided for frequent alternation of operation between one or more ma-
chines and are needed there on a temporary basis, for commissioning or
setting up purposes.
By means of several measures, such as bridging connectors or relay circuits,
the emergency stop circuits of the machine are bridged when the handheld
terminal is unplugged so that the machine can also continue to run in normal
operation without the handheld terminal. Start-up and operation of the machine
can then take place using an independent operating device.
These handheld terminals share the same problems as the radio terminals,
since due to frequent plugging and unplugging it cannot be ruled out that dis-
connected handheld terminal’s with ineffective stop buttons may be left lying
or hanging temporarily in a machine shop or factory in the neighbourhood of
working machines and may be mistaken for functional units in an emergency
situation.
This special case is not clearly treated in the corresponding Standards. How-
ever, in the Product Standards for presses (EN 692:2004, EN 693:2001,
EN 12622:2001, EN 13736:2003) one finds the following clear statement:
"Any disconnectable control station shall not incorporate an emergency
stop button if the press can be operated while this controls station is
disconnected."
Further Product Standards are currently under review.
In several discussions with external notified bodies and technical committees
it was also determined that temporary, plug-in handheld terminals should be
treated as radio handheld terminal’s.
The approach to constructively eliminate hazards by using clear colour coding,
in preference to any organisational measures, also corresponds to the “Prin-
ciples for the Integration of Safety” of the Machinery Directive and is therefore
legally binding.
For this reason, temporary plug-in handheld terminals may likewise only be
equipped with a grey stop button.
Since handheld terminals made by several other manufacturers are on the
market with a grey stop button and have been certified by nominated test cen-
tres, the state of the art requirement is also met.
14.2.10 Information about Enabling Devices
Many machines have both a normal and special operating modes.
CE Conformity, Directives and Standards KeTop T50VGA
© KEBA 2009
User's Manual V1.50 140