DEVICE DESCRIPTION
2
7
H250 M10
www.krohne.com
06/2012 - 4001058901- MA H250/M10-Ex-II2G-AD R02 en
2.6 Protection types
The variable area flowmeter is designed with protection type flameproof enclosure "d", acc. to
EN 60079-1.
The marking is: II 2G Ex d IIC T6
II 2G Ex d IIC T6
II 2G Ex d IIC T6
II 2G Ex d IIC T6
2.7 Ambient temperature / temperature classes
Because of the influence of the temperature of the product, no fixed temperature class is
assigned to variable area flowmeters. In fact, the temperature class of a device is a function of
the temperature of both the product and the environment. Please see the following tables for the
assignments.
The tables take into account the following parameters:
•
Maximum values P
v
•
Ambient temperature T
amb.
•
Product temperature T
m
•
Heat resistance of the connecting cable
For certain device version, lower values apply due to differing boundary conditions (e.g. lining
materials). Here the user should consult the technical data sheet.
The marking contains the following information:
The marking contains the following information:
The marking contains the following information:
The marking contains the following information:
II
IIII
II
Explosion protection Group II
2222
Equipment category 2
G
G
G
G
Gas explosion protection
Ex d
Ex d
Ex d
Ex d
Electronics compartment - protection type flameproof enclosure "d"
IIC
IIC
IIC
IIC
Suitable for gas groups IIC, IIB and IIA
T6
T6
T6
T6
Suitable for temperature classes T6 ... T1
Gb
Gb
Gb
Gb
EPL, suitable for zone 1
INFORMATION!
The maximum permissible product temperatures listed in the tables are valid under
the following conditions:
•
The measuring device is installed and operated in accordance with the installation
instructions in the standard documentation.
•
It must be ensured that the flowmeter is not heated by the effects of additional heat radiation
(sunshine, neighbouring system components) and thus operated above the permissible
ambient temperature range.
•
Insulation must be limited to the piping.
Unobstructed ventilation of the indicator part must be ensured.
AD_H250_M10_II2G_R02_en_058901_PRT.book Page 7 Tuesday, June 26, 2012 7:20 AM