BEKA BA534D, Manual

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5
3.3 Pulse input
As shown in Fig 2, the BA534D will count pulses
from a wide variety of transducers enabling it to
display the output from almost any flowmeter.
The instrument has one pulse input, but two sets
of input terminals enable it to accommodate
different types of transducers. Terminals 5 and 6
are for pulse sources that need powering and
terminals 3 and 4 are for voltage pulse inputs.
Note: Only one pair of input terminals may be
used at a time. i.e pulses can not be counted
from terminals 3 & 4 and from terminals 5 & 6 at
the same time.
The following table shows the switching
thresholds for the various transducers, plus the
maximum operating frequency and the input
terminal numbers. For reliable counting the input
signal must fall below the lower threshold and rise
above the upper threshold.
Switching
thresholds
Freq
max
Input
terminals
Switch
100
Ω
1000
Ω
100Hz 5 & 6
Proximity
detector
1.2mA 2.1mA 5 kHz 5 & 6
Open
collector
2k
Ω
10k
Ω
5kHz 5 & 6
Magnetic
pick-off
0mV 20mV
peak
5kHz 3 & 4
Voltage
pulse
1.0V 3.0V 5kHz 3 & 4
3.4 Remote reset
The BA534D total display is reset to zero when
terminals 7 & 8 are connected together for more
than one second. Permanent interconnection of
these terminals will stop totalisation and may be
used as an inhibit function. There is no practical
limit on the distance that the reset switch may be
from the totaliser.
Alternatively, the BA534D may be programmed so
that the total display is reset to zero when the
Up
and Down push-buttons are operated
simultaneously for more than two seconds. – see
5.12
4. INSTALLATION
4.1 Location
The BA534D rate totaliser is housed in a robust
IP66 glass reinforced polyester (GRP) enclosure
incorporating an armoured glass window and
stainless steel fittings. It is suitable for exterior
mounting in most industrial environments,
including off-shore and waste water treatment.
Please consult BEKA associates if high vibration
is anticipated.
The BA534D enclosure is surface mounting.
Accessory kits described in sections 8.7 & 8.8 of
this manual enable the instrument to be mounted
onto a vertical or horizontal pipe, or directly onto a
flowmeter conduit entry.
The field terminals and the two mounting holes
are located in a separate compartment with a
sealed cover allowing the instrument to be
installed without exposing the display assembly.
The BA534D earth terminal is connected to the
internal EMC filters. For maximum radio frequency
interference rejection this terminal should be
connected to a local earth, or to an earthed cable
screen.
The BA534D enclosure is supplied with a bonding
plate to ensure electrical continuity between the
three conduit / cable entries.
4.2 Installation Procedure
Fig 3 illustrates the instrument installation
procedure.
a. Remove the instrument terminal cover by
unscrewing the two captive 'A' screws.
b. Mount the instrument on a flat surface and
secure with two M6 screws through the 'B'
holes. Alternatively use one of the mounting
kits described in section 8.7 and 8.8
c. Remove the temporary dust seals from the
three cable entries and install the required
glands, conduit fittings or blanking plugs.
Note: The temporary dust seals fitted for
transit do not maintain the IP66 protection of
the BA534D enclosure.
d. Connect the field wiring to the terminals as
shown in Fig 4.
e. Replace the instrument terminal cover and
evenly tighten the two 'A' screws.