KROHNE H250 Series Wiring diagram

Variable area flowmeter
Equipment category II 2 G and II 2 D, EPL Gb and Db
in protection type intrinsic safety "i"
DK37/M8 - H250/M8
DK37/M8 - H250/M8DK37/M8 - H250/M8
DK37/M8 - H250/M8 Supplementary Instructions
Supplementary InstructionsSupplementary Instructions
Supplementary Instructions
© KROHNE 05/2018 - 4005351602 - AD DK37/H250/M8 II2GD R02 en

CONTENTS
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DK37/M8 - H250/M8
1 Safety instructions 3
1.1 General notes ................................................................................................................... 3
1.2 EU conformity ................................................................................................................... 3
1.3 Approval according to the IECEx scheme ........................................................................ 3
1.4 Safety instructions............................................................................................................ 4
2 Device description 5
2.1 Device description ............................................................................................................ 5
2.2 Description code............................................................................................................... 6
2.3 Marking............................................................................................................................. 8
2.4 Flammable products ........................................................................................................ 9
2.5 Equipment category .........................................................................................................9
2.6 Types of protection ......................................................................................................... 10
2.7 Ambient temperature / temperature classes / product temperature .......................... 11
2.8 Surface temperature for equipment category II 2 D...................................................... 13
2.9 Electrical data................................................................................................................. 13
3 Installation 14
3.1 Mounting ......................................................................................................................... 14
3.2 Special conditions........................................................................................................... 14
4 Electrical connections 15
4.1 General notes ................................................................................................................. 15
4.2 Power supply .................................................................................................................. 16
4.3 Inputs/Outputs................................................................................................................ 16
4.4 Grounding and equipotential bonding............................................................................ 17
5 Operation 18
5.1 Start-up........................................................................................................................... 18
5.2 Operation ........................................................................................................................ 18
5.3 Electrostatic charge .......................................................................................................18
6 Service 19
6.1 Maintenance ................................................................................................................... 19
6.2 Dismantling .................................................................................................................... 19

SAFETY INSTRUCTIONS 1
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1.1 General notes
This additional instruction applies to explosion-protected versions of variable area flowmeter
with electrical built-ins with protection type intrinsic safety "i", equipment category II 2 G and
II 2 D or EPL Gb and Db.
It completes the standard documentation for the non-explosion protected versions.
The information given in this instruction contains only the data relevant to explosion protection.
The technical details given in the manual for the non-explosion protected versions remain
unchanged unless excluded or superseded by this supplementary instruction.
1.2 EU conformity
The manufacturer declares with the EU declaration of conformity on his own responsibility
conformity with the protection goals of directive 2014/34/EU for use in hazardous areas with gas
and dust.
Conformity with harmonised standards was checked by a notified body in accordance with
EN 60079-0:2012 and EN 60079-11:2012.
The EU declaration of conformity for the equipment category II 2 G and II 2 D is based on the EU
type examination certificate:
The "X" after the certificate number refers to special conditions for safe use of the device, which
have been listed in these instructions.
If necessary, the EU type examination certificate can be downloaded from the manufacturer's
website.
1.3 Approval according to the IECEx scheme
Conformity for use in hazardous areas with gas and dust was tested in accordance with the
"IECEx Certification Scheme for Explosive Atmospheres" according to
IEC 60079-0:2011, IEC 60079-15:2010 and IEC 60079-31:2013.
The number of the IECEx certificate is:
The "X" after the certificate number refers to special conditions for safe use of the device, which
have been listed in these instructions.
If needed, the IEC certificate can be downloaded from the manufacturer's website.
KIWA 15 ATEX 0038 X
KIWA 15 ATEX 0038 XKIWA 15 ATEX 0038 X
KIWA 15 ATEX 0038 X
IECEx KIWA 15.0020 X
IECEx KIWA 15.0020 XIECEx KIWA 15.0020 X
IECEx KIWA 15.0020 X

1 SAFETY INSTRUCTIONS
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1.4 Safety instructions
If these instructions are not followed, there is a risk of explosion.
Assembly, installation, start-up and maintenance may only be performed by personnel trained in
explosion protection!
CAUTION!
The operator or his agent is responsible for observing any additional standards, directives or
laws if required due to operating conditions or place of installation.
This applies in particular to the use of easily detachable process connections when measuring
flammable media.

DEVICE DESCRIPTION 2
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2.1 Device description
Variable area flowmeters measure and display the volume flow of flammable and non-
flammable gases and liquids.
Figure 2-1: Available indicators
1 Indicator M8E.: one signal output 4...20 mA with a bargraph indicator
2 Indicator M8M.: up to two separately adjustable electrical limit switches

2 DEVICE DESCRIPTION
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2.2 Description code
Type series H250
Type series H250Type series H250
Type series H250
The safety description code consists of the following elements*:
Figure 2-2: Safety description code
1 Type series of measuring unit H250
Type series of measuring unit H250Type series of measuring unit H250
Type series of measuring unit H250
2 Materials / versions
Materials / versionsMaterials / versions
Materials / versions
RR - stainless steel
C - PTFE or PTFE with ceramic liner
HC - Hastelloy
®
Ti - Titanium
F - Food
3 Type series of indicators
Type series of indicatorsType series of indicators
Type series of indicators
M8 - Indicator M8
4 Design of indicator M8
Design of indicator M8Design of indicator M8
Design of indicator M8
MG - mechanical indicator
EG - electronic indicator with signal output 4...20 mA
5 Design of indicator housing
Design of indicator housingDesign of indicator housing
Design of indicator housing
without - indicator housing in PPS
R - indicator housing in stainless steel
6 Limit switch (M8MG version)
Limit switch (M8MG version)Limit switch (M8MG version)
Limit switch (M8MG version)
K1 - one limit switch
K2 - two limit switches
7 Version
VersionVersion
Version
Ex - explosion-protected version

DEVICE DESCRIPTION 2
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Type series DK37
Type series DK37Type series DK37
Type series DK37
The safety description code consists of the following elements*:
* positions which are not needed are omitted (no blank positions)
Figure 2-3: Safety description code
1 Type series of measuring unit DK
Type series of measuring unit DKType series of measuring unit DK
Type series of measuring unit DK
2 Type series of signal converter 37
Type series of signal converter 37Type series of signal converter 37
Type series of signal converter 37
3 Type series of indicators
Type series of indicatorsType series of indicators
Type series of indicators
M8M - mechanical indicator
M8E - electronic indicator
4 Design of indicator housing
Design of indicator housingDesign of indicator housing
Design of indicator housing
without - indicator housing in PPS
R - indicator housing in stainless steel
5 Optional differential pressure regulator
Optional differential pressure regulatorOptional differential pressure regulator
Optional differential pressure regulator
RE - inlet pressure regulator
RA - outlet pressure regulator
6 Limit switch (M8M version)
Limit switch (M8M version)Limit switch (M8M version)
Limit switch (M8M version)
K1 - one limit switch
K2 - two limit switches

2 DEVICE DESCRIPTION
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2.3 Marking
The marking of the entire device is clearly visible on the indication unit, in accordance with the
designation code.
Additional markings on the housing cover:
•SN - serial number
•SO - sales order / item
•PA - order
•Vxxx - product configurator code
•AC - article code
Additional plate
The association of the housing cover to the device is confirmed by an additional plate with the
serial number on the interior of the indicator part.
Figure 2-4: Example of a nameplate
1 Device type
2 Manufacturer
3 Identification number of the notified body ATEX & PED
4 Rating data: temperature & pressure rating
5 PED data
6 Ex data
7 Electrical connection data
8 QR code
9 Note to observe the documentation and for disposal

DEVICE DESCRIPTION 2
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2.4 Flammable products
Atmospheric conditions:
Atmospheric conditions:Atmospheric conditions:
Atmospheric conditions:
The ATEX directive does not stipulate values for atmospheric conditions. However, for
determining the explosion characteristic parameters of temperature and pressure range, the
following is assumed as a basis:
T
atm
= -20...+60°C / -4...+140°F and P
atm
= 0.8...1.1 bar / 11.6...15.9 psi
Outside of these ranges, for most mixtures no key figures are available for the ignition
behaviour.
Operating conditions:
Operating conditions:Operating conditions:
Operating conditions:
Variable area flowmeters operate outside of atmospheric conditions, which means that
explosion protection, regardless of the zone assignment, is fundamentally not applicable due to
the lack of key safety data for the interior of the measuring unit.
2.5 Equipment category
Variable area flowmeters are designed in accordance with EN 60079-0 and EN 60079-11 in
category II 2 G or EPL Gb for use in zone 1.
Depending on the device version, variable area flowmeters are also designed in
category II 2 D or EPL Db for use in zone 21.
The inside of the measuring unit is also approved for zone 1.
WARNING!
Operation with flammable products is only permitted as long as no explosive fuel/air mixture
builds up on the inside of the flowmeter under operating conditions. The operator is responsible
to ensure that the flowmeter is operated safely in terms of the temperature and pressure of the
products used. In case of operation with flammable products the measuring units must be
included in the periodic pressure tests of the system. When using the device version H250/C...
(PTFE version, non-conductive) the minimum conductivity of the media must be 10
-8
S/m, in
order to avoid danger from electrostatic charge.
INFORMATION!
Definition of zone 1 according to EN 1127-1, Appendix B:
An area in which an explosive atmosphere, as a result of the mixture of flammable substances in
the form of gas, steam or mist with air, under normal operation may occasionally occur.
Definition of zone 21 according to EN 1127-1, Appendix B:
An area in which an explosive atmosphere may occasionally occur in the form of a cloud of
flammable dust in the air under normal operation.

2 DEVICE DESCRIPTION
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2.6 Types of protection
The variable area flowmeter is designed with protection type intrinsic safety "i" according to
EN 60079-11.
The identification for equipment category II 2 G or EPL Gb is:
II 2 G Ex ia IIC T6...T3 Gb
II 2 G Ex ia IIC T6...T3 GbII 2 G Ex ia IIC T6...T3 Gb
II 2 G Ex ia IIC T6...T3 Gb
The additional identification of the version for the equipment category II 2 D and EPL Db is:
II 2 D Ex ia IIIC T75
II 2 D Ex ia IIIC T75II 2 D Ex ia IIIC T75
II 2 D Ex ia IIIC T75°C ... T200
C ... T200C ... T200
C ... T200°C Db
C DbC Db
C Db
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
2
22
2Equipment category 2
G
GG
GGas explosion protection
Ex ia
Ex iaEx ia
Ex ia Explosion protection through intrinsic safety, protection level "ia"
IIC
IICIIC
IIC Gas group, suitable for gas groups IIC, IIB and IIA
T6...T3
T6...T3T6...T3
T6...T3 Temperature class range, suitable for temperature classes T6...T1
Gb
GbGb
Gb EPL, suitable for zone 1 and zone 2
INFORMATION!
For the equipment category II 2 G and EPL Gb, connection to an intrinsically safe circuit with
protection level "ib" is required.
When connecting the variable area flowmeter to an intrinsically safe circuit with protection level
"ia", a higher protection level is given.
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
2
22
2Equipment category 2
D
DD
DDust ignition protection
Ex ia
Ex iaEx ia
Ex ia Explosion protection through intrinsic safety, protection level "ia"
IIIC
IIICIIIC
IIIC Dust group, suitable for groups IIIC, IIIB and IIIA
T75
T75T75
T75°C ... T200
C ... T200C ... T200
C ... T200°C
CC
CMaximum surface temperature at +65°C / +149°F ambient temperature
Db
DbDb
Db EPL, suitable for zone 21 and zone 22
INFORMATION!
For the equipment category II 2 D and EPL Db, connection to an intrinsically safe circuit with
protection level "ib" is required.
When connecting the variable area flowmeter to an intrinsically safe circuit with protection level
"ia", a higher protection level is given.