5
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
Open
collector
2k
Ω
10k
Ω
10kHz
5 & 6
Magnetic
pick-off
0mV
40mV
10kHz
3 & 4
Voltage
pulse
1.0V
3.0V
10kHz
3 & 4
3.3 Remote reset
The BA544D 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 BA544D 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 5.13
Note:
Each time the total display is reset to
zero, the grand total is stored in permanent
memory.
4. INSTALLATION
4.1 Location
The BA544D 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 installations. Please consult
BEKA associates if high vibration is
anticipated.
The BA544D enclosure is surface mounting.
Accessory kits described in sections 8.4 & 8.5
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 BA544D 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 BA544D 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 8.4 &
8.5
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 BA544D enclosure.
d. Connect the field wiring to the terminals
as shown in Fig 4.
Summary of Contents for BA544D
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