6
5. INSTALLATION
5.1 Location
The BA304C indicator can be supplied in either a
glass reinforced polyester (GRP), or an epoxy
painted aluminium enclosure. Both provide IP66
protection and have a toughened glass window
and stainless steel fittings. The GRP enclosure is
suitable for most industrial installations including
off-shore and waste water treatment applications.
For installations where solvents may be present,
the aluminium enclosure provides maximum
protection, but it is not recommended for offshore
applications.
Both enclosures are surface mounting, but may be
pipe or panel mounted using the accessory kits
described in section 8 of this manual.
To simplify installation, the enclosure can be
installed and the field wiring terminated prior to the
indicator assembly being fitted. The enclosure
contains diodes to maintain continuity of the
4/20mA loop when the indicator assembly is not
present. Terminals 2 and 4 are internally joined
and may be used for linking the return 4/20mA wire
- see Fig 2. Similarly, terminals 5 and 6 are
internally joined and may be used for linking the
cable screens. Terminal 7 is internally connected
to an insulated radio frequency screen in the GRP
enclosure, and to the case in the aluminium
enclosure.
5.2 Installation Procedure
Fig 4 illustrates the instrument installation
procedure.
a. Remove the enclosure cover by unscrewing
the four captive 'A' screws.
b. Remove the indicator assembly from the
enclosure by unscrewing the three captive
'B' screws.
c. Mount the enclosure on a flat surface and
secure with screws or bolts through the four
corner 'C' holes. Alternatively use one of the
pipe or panel mounting kits described in
sections 8.5 and 8.6
d. Remove the temporary hole plug and install
a gland or conduit fitting with the required
ingress protection. If two entries are
required, replace the supplied IP66 stopping
plug with a gland or conduit fitting having the
required ingress protection.
e. Connect the field wiring to the terminals as
shown in Fig 5.
f. Replace the indicator assembly and evenly
tighten the three 'B' screws.
g. Replace the enclosure cover and evenly
tighten the four 'A' screws.
Fig 4 BA304C installation procedure
5.3 EMC
The BA304C complies with the requirements of the
European EMC Directive 2004/108/EC. For
specified immunity all 4/20mA wiring should be in
screened twisted pairs, with the screen earthed
within the safe area. Terminal 7 should be
connected to a local earth or to a cable screen
which is earthed in the safe area.
Fig 5 Dimensions and terminal connections