BEKA BA334NG, Manual

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4.2.3 Open collector input
Flowmeters with an open collector output located in
Zone 2 or in the safe area may be directly
connected to input terminals 5 & 6 providing the
flowmeter and associated wiring can withstand a
500V rms insulation test to earth.
The BA334NG contains a configurable debounce
circuit to prevent false triggering. See section 6.7.
4.2.4 2-wire proximity detector input
Most Zone 2 certified flowmeters incorporating a
NAMUR 2-wire proximity detector may be directly
connected to a BA334NG input terminals 5 & 6
providing minimum operating voltage is greater than
7.5V. The flowmeter and the associated wiring
should be able to withstand a 500V rms insulation
test to earth.
The BA334NG contains a configurable debounce
circuit to prevent false triggering. See section 6.7.
4.2.5 Magnetic pick-off input
Flowmeters incorporating a magnetic pick-off to
sense flow will usually have a low level ac voltage
output which a BA334NG Rate Totaliser can sense
when configured for a
CoiL
input. The Rate
Totaliser input terminals 5 and 6 may be connected
to any Zone 2 certified magnetic pick-off output
flowmeter, providing the output in normal operation
is equal to or less than 30V the Rate Totaliser's Ui.
The flowmeter and associated wiring should be able
to withstand a 500V rms insulation test to earth.
The BA334NG contains a configurable debounce
circuit to prevent false triggering. See section 6.7.
4.2.6 Voltage pulse input
Two voltage pulse input ranges are selectable in the
BA334NG Rate Totaliser configuration menu,
VoLt5 L
and
VoLt5 H
. The Rate Totaliser input
terminals 5 and 6 may be connected to any Zone 2
certified voltage pulse output flowmeter, providing
the output in normal operation is equal to or less
than 30V the Rate Totaliser's Ui. The flowmeter and
associated wiring should be able to withstand a
500V rms insulation test to earth.
The BA334NG contains a configurable debounce
circuit to prevent false triggering. See section 6.7.
4.3 Remote reset
The BA334NG Rate Totaliser's total display may
be remotely reset to zero by connecting terminals
RS1 and RS2 together. Permanent
interconnection inhibits totalisation. Remote
resetting may be accomplished by any
mechanically operated switch located in Zone 2 as
the Rate Totaliser's reset circuit is non incendive.
The reset switch and the associated wiring should
be able to withstand a 500V rms insulation test to
earth.
A BA334NG may also be remotely reset from the
safe area. Any switch may be used. Fig 4
illustrates how a BA334NG may be reset from both
the safe and the hazardous area.
The BA334NG total display may also be reset
when the
&
and
*
push buttons are operated
simultaneously in the totalising mode i.e. when the
instrument is displaying flow. See 6.19