BEKA BA405C, Manual

Page: 4 / 16

4
3.3 Safety parameters
The BA405C EC-Type Examination Certificate
specifies the maximum input safety parameters for
the two 4/20mA terminals 1 and 3, and the
equivalent internal capacitance and inductance
that appears between the terminals. Using the
entity concept and these safety parameters,
suitable Zener barriers or galvanic isolators may
be selected and the maximum permissable cable
parameters calculated.
The following figures are reproduced from the
ATEX certificate ITS03ATEX21103
Terminals 1 and 3:
(4/20mA output terminals)
Basic BA405C set point station without
optional loop powered display backlight.
Maximum input safety parameters
Ui = 30V dc
Ii = 200mA dc
Pi = 0.85W
Equivalent capacitance and inductance
Ci = 40nF
Li = 0.01mH
With loop powered display backlight
Terminals 1 and 13
(3 and 12 connected in series)
Maximum input safety parameters
Ui = 30V dc
Ii = 200mA dc
Pi = 0.85W
Equivalent capacitance and inductance
Ci = 40nF
Li = 0.03mH
Separately powered display backlight
Terminals 12 and 13
Maximum input safety parameters
Ui = 28V dc
Ii = 159mA dc
Pi = 0.8W
Equivalent capacitance and inductance
Ci = 30nF
Li = 0.01mH
3.4 Zones, Gas Groups and T rating
The BA405C and both the optional display
backlights have been certified as Group II category
1G apparatus, EEx ia IIC T5. When powered via
a compatable Zener barrier or galvanic isolator the
BA405C manual set point station may be installed
in:
Zone 0 explosive gas air mixture
continuously present.
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
Having a temperature classification of:
T1 450°C
T2 300°C
T3 200°C
T4 135°C
T5 100°C
WARNING installation in Zone 0
When installed in a Zone 0 potentially
explosive atmosphere requiring apparatus
of Category 1G, the set point station shall be
installed such that even in the event of rare
incidents, an ignition source due to impact
or friction between the aluminium enclosure
at the rear of the instrument mounting panel
and iron/steel is excluded.
3.5 Certification label information
The ATEX certification information is shown on a
label fitted in a recess on the top outer surface of
the enclosure.
BA405C ATEX certification label