TT-107IU Silicone Keyboard - Technical Documentation
15.05.2012 © E.L.B. Ex-Geraete Bachmann GmbH Page 9
IP6...:
Dust proof, complete contact protection
IP...6:
Tall seas / strong water beam
IP...8:
Total immersion TT-107
I
U: 1 hour at 1 m below water surface
Wall thickness is generally more than 5 mm, but much less around the keys
and above of the lamps (under the keys “Num” and “
“and between the keys
“Esc” and “1”). Even hardly visible damages may decrease the IP protection
here and make the dust protection become invalid. Please watch these areas.
6.4 Extension cables
USB plugs and sockets of USB cables are not allowed in hazardous areas, but
the leads of such cables may be connected in Ex e terminal blocks inside of
Ex e junction boxes (Ex e = kind of protection “increased safety”), if additional
rules for safe connections are watched. So the diameters of the usually thin
cable cores of USB and PS/2 cables e. g. must be increased by sleeves to
achieve the minimum diameters allowed for the terminal blocks. Measures can
be found in the certificates of the terminal blocks or the junction boxes.
The maximum cable length is not predictable, because many USB devices
refuse to install themselves, if the USB cable does not transmit frequencies,
which are much higher than the actual data transmission rate.
If you need especially long cables,
please give us a message.
The lead colours of USB cables are
standardized, see drawing.
For especially long cables
however we presume to use
different colours.
6.5 Connectors in hazardous areas
In hazardous dust environments USB plugs and sockets are not allowed,
because conductive dust could accumulate there
and catch fire by short circuiting contacts.
Inside of hazardous gas environments the
keyboard TT-107IU may be plugged
and unplugged, if it is supplied by
the intrinsically safe USB supply
series W...-Q, which have their
own manual. For these supplies
e. g. the lockable sockets
USock1 and USock2 are
available, see drawing.
Please note that USock1
connects the USB cable
shield with the plug thread.
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USB socket
(PC or intrinsic safe supply)
USB plug
(keyboard)
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Kabellänge zwischen Buchse
und Stecker ca. 50 cm
