5
3.2 Zones, gas groups and T rating
Both
models
have
been
certified
Ex eb ib mb IIC T5 Gb -40ºC ≤ Ta ≤ +60º. Types
of explosion protection are listed in alphanumeric
order. When connected in series with a 4/20mA
loop the indicators may be installed in:
Zone 1
explosive gas air mixture likely
to occur in normal operation.
Zone 2
explosive gas air mixture not
likely to occur, and if it does
will only exist for a short time.
Be used with gases in groups:
Group
A
propane
Group
B
ethylene
Group
C
hydrogen
In gases that may be used with equipment having
a temperature classification of:
T1
450°C
T2
300°C
T3
200°C
T4
135°C
T5
100°C
Rated voltage U
N
U
N
30V dc.
At ambient temperatures between -40 and +60°C.
This allows both indicators to be used with most
common industrial gases except carbon disulphide
and ethyl nitrite which have an ignition temperature
of 95°C.
3.3
Specific conditions of use
The IECEx and ATEX certificate numbers have an
'X' suffix indicating that specific conditions apply.
Both certificates state that the indicators should be
powered from a SELV (
separated or safety extra
low voltage
) or PELV (
protected extra-low voltage)
supply}
, or from an adequately approved supply
providing double or reinforced insulation as
specified in IEC 60079-14.
This requirement also applies to flameproof
equipment and does not usually cause any
difficulties because the power supply is required to
be safe for personnel contact. In European terms,
compliance with the Low Voltage Directive ensures
that this requirement is met.
Like most flameproof indicators, the BA304SG and
BA324SG
Ex eb ib mb
indicators
have no
maximum i n p u t current rating, only a maximum
voltage rating U
N
of 30V. The BA304SG and
BA324SG indicators may therefore be used in
exactly the same way as a certified flameproof
indicator, providing the loop supply voltage is
isolated and equal to or less than 30V.
3.4
Certification label information
The certification information label is fitted on the
top surface of the instrument assembly. It shows
the ATEX and IECEx certification information and
BEKA associates name and location.
Non
European certification information may also be
shown. The instrument serial number and date of
manufacture are recorded on a separate label
inside the instrument enclosure.
BA304SG certification label
