KROHNE BM 70A EEx EN - Manual (Page 7)

7 www.krohne.com 07/2010 - 4000662402 MA BM70x-Ex-AD-R02-en
3.1.4. I/O functions
The following limit values need to be taken into account when connecting the I/O interfaces of the
BM 70..-Ex level gauges:
BM 70./.-Ex with non-intrinsically safe I/O functions
I/O function
(1)
Nominal values of the non-
certified receiver instrument
Additional restriction
Acc. to standard Installation &
Operating Instructions
Acc. to standard Installation &
Operating Instructions
Power for receiver instruments,
max. 250 V
(1)
Only for connection to circuits with “functional extra-low voltage with safety separation (PELV)“
BM 70A/.i-Ex and BM 70Pi/.-Ex with intrinsically safe I/O functions
I/O function Identifying marking Maximum safety values
Passive current output
Ex ia IIC or
Ex ib IIC Ui = 30V Ii = 250mA Pi = 1,0W
Ci = 5nF Li = negligible
Passive switching output
Ex ia IIC or
Ex ib IIC Ui = 30V Ii = 250mA Pi = 1,0W
Ci = 5nF Li = negligible
Interface
PROFIBUS-PA
(1)
Ex ia IIC or
Ex ib IIC/IIB Ui = 30V Ii = 380mA Pi = 5,32W
Ci = 5nF Li = negligible
Interface
Fieldbus FF Ex ia IIC or
Ex ib IIC/IIB Ui = 30V Ii = 380mA Pi = 5,32W
Ci = 5nF Li = negligible
(1)
Suitable for connection to intrinsically safe fieldbus systems based on the FISCO Model
The intrinsically safe circuits of the I/O functions are galvanically isolated both from ground and also
from each other (test voltage > 500 VAC).
Furthermore, all intrinsicaly safe circuits are safety-separated from the non-intrinsically safe power
circuits up to a peak voltage of 375 V.
BM 702-Ex / BM 702 A-Ex with intrinsically safe I/O functions
I/O functions Identifying marking Maximum safety values
Passive current output
Ex ia IIC or
Ex ib IIC Ui = 30V Ii = 250mA Pi = 1,0W
Ci = 11nF Li = negligible
The intrinsically safe circuit is galvanically isolated from ground (test voltage > 500 VAC).