BEKA BA334NG, Manual

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In gases that may safely be used with equipment
having a temperature classification of:
T1 450
o
C
T2 300 o C
T3 200 o C
T4 135 o C
T5 100
o
C
At ambient temperatures between -40 and +60 o C.
This allows use with all commonly used industrial
gases except carbon disulphide CS
2
.
3.3 Safety parameters
The certificate specifies input safety parameters in
normal operation i.e. without faults for all the
instrument terminals. Where only a voltage or only
a current is specified, the unspecified parameter will
be defined by components within the instrument.
3.4 Special conditions for safe use
The Ex nA certificate has an ‘X’ suffix indicating that
the certificate defines special conditions for safe
use. These state that the BA334NG Rate Totaliser
should be:
a. Supplied from a limited energy circuit with
output parameters in normal operation equal
to, or less than the instrument’s input
parameters. The certificate states that It is
not necessary to power the instrument from
an intrinsically safe interface, such as a
certified shunt diode safety barrier or a
galvanic isolator to comply with this
requirement.
b. Fitted with cable entry glands or conduit
fittings which maintain the impact and ingress
protection of the enclosure. Certified Ex e or
Ex n components satisfy these requirements.
The BA334NG is supplied fitted with one
certified M20 stopping plug and one
temporary hole plug which should be replaced
with the required gland or conduit fitting.
3.5 Power supply
The input safety parameters for the power supply
terminals 1 and 2 are:
Ui = 30V dc
Ii = 100mA
This allows the BA334NG to be powered from any
dc supply which in normal operation has an output
of less 30V and 100mA. See section 4.1 for power
supply recommendations.
3.6 Pulse input
The BA334NG Rate Totaliser has a single pair of
pulse input terminals 5 and 6 that may be
configured for use with different types of sensor.
For sensors that require energising to determine
their state, such as switch contacts or a 2-wire
proximity detector, an external link between
terminals 3 & 4 of the BA334NG connects an
internal 7V, 6mA supply to the input terminals.
Energising is not required when the Rate Totaliser
input is connected to a voltage pulse source.
Fitting an external link between terminals 3 & 4
changes the Rate Totaliser's pulse input safety
parameters in normal operation as shown below.
This table also shows the types of sensor requiring
energising (link fitting).
Safety parameters
Input Output
Type of input Link 3 & 4 Ui Uo Io
Switch contact Yes 15V 10.5V 9.2mA
Proximity detector Yes 15V 10.5V 9.2mA
Open collector Yes 15V 10.5V 9.2mA
Magnetic pick-off No 30V 1.1V 0.5mA
Voltage input (low) No 30V 1.1V 0.5mA
Voltage input (high) No 30V 1.1V 0.5mA
3.7 Remote reset terminals
The BA334NG total display my be reset to zero by
connecting the external reset terminals RS1 and
RS2 together for more than one second. The two
reset terminals have the following safety
parameters in normal operation:
Ui = 30V
Uo = 3.8V
Io = 1mA
3.8 Certification label information
The Rate Totaliser certification information label is
fitted in a recess on the top outer surface of the
enclosure. It shows the ATEX and IECEx
certification information plus BEKA associates
name, location, year of manufacture and the
instrument serial number.
BA334NG Certification information label