7
6. INSTALLATION
BEKA Application Guide AG310 provides
comprehensive information on the installation of
[Extra low voltage dc] Ex nA instrumentation. The
guide may be downloaded from the BEKA website.
6.1 Location
The BA474ND Indicating Temperature Transmitter 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 offshore and wastewater treatment
installations. Please consult BEKA associates if high
vibration is anticipated.
The BA474ND enclosure is surface mounting.
Accessory kits described in sections 10 of this
manual enable the instrument to be mounted onto a
vertical or horizontal pipe.
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 BA474ND earth terminal is connected to the
carbon loaded GRP enclosure. If this enclosure is not
bolted to an earthed post or structure, the earth
terminal should be connected to a local earth.
The BA474ND enclosure is supplied with a bonding
plate to ensure electrical continuity between the three
conduit / cable entries.
The BA474ND liquid crystal display has maximum
contrast when viewed from directly ahead and slightly
below the centre line of the instrument. Without a
backlight there is very little degradation of contrast
when viewed from above the centre line, but slight
degradation may be noticeable when the instrument
is fitted with a backlight.
6.2 Installation Procedure
Fig 4 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 10.3
c. Remove the temporary hole plug and install
an appropriate IP rated Ex n or Ex e cable
gland or conduit fitting. If more than one
entry is required, one or both of the IP66
Ex e stopping plugs may be replaced with
an appropriate IP rated Ex n or Ex e cable
gland or conduit fitting.
d. Connect the field wiring to the terminals as
shown in Fig 5.
e. Replace the instrument terminal cover and
evenly tighten the two 'A' screws.
Fig 4 BA474ND installation procedure