BEKA BA458C, Manual

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Section 3.6 describes the use of external
switches in the hazardous area, but they may
also be located in the safe area.
A certified intrinsically safe relay or a galvanic
isolator with a switch contact output is required
to transfer the switch contact from the safe to
the hazardous area. The combined permitted
input safety parameters for batch controller
terminals S1 to S7 are zero, therefore Zener
barriers can not be used.
Fig 8 shows how the external Stop buttons
may be located in the safe and hazardous
areas.
Fig 8 Stop buttons in hazardous & safe areas
4.5 Inhibit link
Linking terminals 18 and 20 together inhibits
the batch controller input. If linked during a
batch, dispensing will continue but it will not be
shown on the batch display. These terminals
may only be connected to a hazardous area
mechanically operated switch having IP20
protection and able to withstand an ac test
voltage of 500V to earth for one minute. See
section 3.7.
4.6 Security link
Access to the configuration menus is only
available when terminals 18 & 19 are linked
together – see section 6.1. These terminals
may only be linked together at the instrument,
or connected to a hazardous area
mechanically operated switch having IP20
protection and able to withstand an ac test
voltage of 500V to earth for one minute. See
section 3.7.
5. INSTALLATION
5.1 Location
The BA458C is housed in a robust aluminium
enclosure with a toughened glass window
mounted in a Noryl bezel. The front of the
instrument provides IP65 protection and a
gasket seals the joint between the instrument
enclosure and the panel. The instrument may
be installed in any panel providing the
environmental limits shown in the specification
are not exceeded.
Fig 9 shows the overall dimensions of the
BA458C and the panel cut-out. To achieve an
IP65 seal between the instrument enclosure
and the panel, the smaller cut-out must be
used and the instrument secured with four
panel mounting clips.
The BA458C liquid crystal display has
maximum contrast when viewed from directly
ahead and slightly below the centre line of the
instrument.
Fig 9 BA458C dimensions