BEKA BA314NG, Manual

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1. DESCRIPTION
The BA314NG is an Ex nA and Ex tc certified, field
mounting Tachometer primarily intended for
measuring rotational speed within a Zone 2 or 22
hazardous area. To assist with routine maintenance,
the Tachometer includes a run-time clock that records
the number of hours that the monitored machinery has
been operating. The BA314NG is controlled and
configured via the four front panel push buttons, a
user defined four digit code may be entered to prevent
accidental access to the instrument's configuration
menu.
This instruction manual supplements the abbreviated
instruction sheet supplied with each instrument.
The BA314NG has been issued with a Type
Examination Certificate ITS16ATEX48409X by
Notified Body Intertek Testing and Certification Ltd.
This confirms compliance with the type of protection
requirements for non-sparking Ex nA apparatus, and
for dust ignition protection by enclosure Ex tc. This
certificate has been used to confirm compliance with
the European ATEX Directive 2014/34/EU.
For international applications the BA314NG also has
IECEx certification which is described in Appendix 2.
For applications in the USA and Canada the
BA314NG has ETL and cETL approval, see
Appendix 3.
2. OPERATION
Fig 1 shows a simplified block diagram of the
BA314NG Tachometer. The instrument can accept
pulses from most types of sensor and display speed
per second, minute or per hour, plus run-time in
hours on a separate display.
The BA314NG has a single pair of input terminals for
connection to all types of sensor. When connected to
a sensor requiring energising, such as a switch
contact, open collector or a two wire proximity
detector, an external link between terminals 3 and 4
connects power to the sensor input terminals. An
isolated pulse output can be configured to
synchronously retransmit the pulse input, or a
frequency divided frequency output with a defined
pulse width.
Factory fitted accessories include an internally
powered display backlight, dual alarms and an
isolated 4/20mA output which may be configured to
retransmit any part of the speed display.
Fig 1 BA314NG block diagram
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