KROHNE H250 M40 Series Wiring diagram

Equipment category II 2 G / II 2D , EPL Gb / Db
in equipment protection by flameproof enclosures Ex-d and
in equipment dust ignition protection by enclosure Ex-t
H250 M40
H250 M40H250 M40
H250 M40 Supplementary Instructions
Supplementary InstructionsSupplementary Instructions
Supplementary Instructions
© KROHNE 04/2016 - 4002069603 - AD H250-M40-ExII2GD-R03 en

CONTENTS
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H250 M40
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............................................................................................................ 3
2 Device description 4
2.1 Description of device ........................................................................................................ 4
2.2 Description code............................................................................................................... 4
2.3 Marking............................................................................................................................. 5
2.4 Flammable products ........................................................................................................ 6
2.5 Device category ................................................................................................................ 6
2.6 Protection types................................................................................................................ 7
2.7 Ambient temperature / temperature classes.................................................................. 8
2.8 Surface temperature for equipment category II 2 D...................................................... 11
2.9 Electrical data................................................................................................................. 11
3 Installation 12
3.1 Installation...................................................................................................................... 12
3.2 Special conditions........................................................................................................... 13
4 Electrical connections 14
4.1 General notes ................................................................................................................. 14
4.2 Power supply .................................................................................................................. 15
4.3 Inputs/outputs ................................................................................................................ 15
4.4 Grounding and equipotential bonding............................................................................ 16
5 Operation 17
5.1 Start-up........................................................................................................................... 17
5.2 Operation ........................................................................................................................ 17
5.3 Electrostatic charge .......................................................................................................17
6 Service 18
6.1 Maintenance ................................................................................................................... 18
6.2 Dismantling .................................................................................................................... 18

SAFETY INSTRUCTIONS 1
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1.1 General notes
These additional instructions apply to explosion-protected versions of variable area flowmeters
with electrical built-ins and the marking II 2 G or II 2 D. They complete the standard manual for
the non-explosion protected versions.
The information given in this instruction contains only the data relevant to explosion protection
of category 2. The technical details given in the standard manual for the non-explosion protected
versions apply unchanged unless excluded or superseded by these supplementary instructions.
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.
The EU declaration of conformity is based on the EC type examination certificate of the
Physikalisch Technische Bundesanstalt (PTB):
1.3 Approval according to the IECEx scheme
Conformity with IECEx standards was tested in accordance with the IECEx Certification Scheme
for Explosive Atmospheres acc. to IEC 60079-0, IEC 60079-1 and IEC 60079-31. The number of
the IEC certificate is:
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!
PTB 12 ATEX 1025
PTB 12 ATEX 1025PTB 12 ATEX 1025
PTB 12 ATEX 1025
IECEx PTB 12.0034
IECEx PTB 12.0034IECEx PTB 12.0034
IECEx PTB 12.0034
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.

2 DEVICE DESCRIPTION
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2.1 Description of device
Variable area flowmeters measure and display the volume flow of flammable and non-
flammable gases and liquids. Depending on the device version, electrical limit switch contacts
with counter module, reed contacts, a 4...20 mA signal output with HART
®
communication, a
Foundation Fieldbus interface or a Profibus PA interface can be installed in the indication unit.
2.2 Description code
The safety description code * consists of the following elements:
* positions which are not needed are omitted (no blank positions)
1 Type series measuring unit H250
H250 - standard version, vertical upwards
H250H - horizontal orientation
H250U - vertical downwards
2 Measuring unit materials / versions
RR - Stainless steel
C - PTFE or PTFE/ceramics
HC - Hastelloy C
Ti - Titanium
F - Food
3 Heating jacket version
blanc - without heating jacket
B - with heating jacket
4 Signal converter version
M40 - Aluminium housing, painted (standard)
M40S - Aluminium housing with increased corrosion protection
M40R - Stainless steel housing
5 High temperature version
blanc - without HT extension
HT - with HT extension
6 Electrical signal output
blanc - without transmitter
ESK - Electrical signal output 4...20mA (ESK4)
. . . - optionally available with counter, I/O module and display (ESK4-T) or
. . . - Foundation Fieldbus (ESK4-FF) or
. . . - Profibus PA (ESK4-PA)
7 Limit switches
blanc - without limit switches
K1 - One limit switch
K2 - Two limit switches
R1 - 1 reed switch
R2 - 2 reed switches
8 Version
Ex - Explosion-protected version
9 SIL Version
SE - SIL compliant electronic signal output
SK - SIL compliant limit switch

DEVICE DESCRIPTION 2
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2.3 Marking
The marking of the entire device is on the indication unit, where the following identification plate
can be found (see also designation code).
Additional markings on the housing cover:
•SN - serial number
•SO - sales order / item
•PA - order
•Vxxx / Sxxx - 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 2-1: 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 Note to observe the documentation
9 Internet site of the manufacturer

2 DEVICE DESCRIPTION
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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 according to the ATEX directive, 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 Device category
Variable area flowmeters are designed in accordance with EN 60079-0, EN 60079-1 and
EN 60079-31 in category II 2 G / II 2 D or EPL Gb and EPL Db for use in zone 1 or 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 acc. to EN 1127-1, Appendix B:
An area in which an explosive atmosphere may occasionally occur as a result of the mixture of
flammable substances in the form of gas, steam or mist with air under normal operation.
Definition of zone 21 acc. 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.

DEVICE DESCRIPTION 2
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2.6 Protection types
The variable area flowmeter is designed for equipment protection "flameproof enclosure",
protection level "Gb" acc. to EN 60079-1 and "Equipment - dust ignition protection through
enclosure", protection level "Db" acc. to EN 60079-31.
The marking is:
II 2G Ex d IIC T6...T1 Gb or II 2G Ex d IIB T6...T1 Gb or II 2D Ex t IIIC T70
II 2G Ex d IIC T6...T1 Gb or II 2G Ex d IIB T6...T1 Gb or II 2D Ex t IIIC T70II 2G Ex d IIC T6...T1 Gb or II 2G Ex d IIB T6...T1 Gb or II 2D Ex t IIIC T70
II 2G Ex d IIC T6...T1 Gb or II 2G Ex d IIB T6...T1 Gb or II 2D Ex t IIIC T70 °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
D
DD
DDust ignition protection
Ex d
Ex dEx d
Ex d Protection type flameproof enclosure
Ex t
Ex tEx t
Ex t Protection type "Equipment - dust ignition protection through enclosure"
IIC
IICIIC
IIC Gas group, suitable for gas groups IIC, IIB and IIA
IIB
IIBIIB
IIB Gas group, suitable for gas groups IIB and IIA
IIIC
IIICIIIC
IIIC Dust areas, suitable for Group IIIC, IIIB and IIIA
T6...T1
T6...T1T6...T1
T6...T1 Temperature class, suitable for temperature classes T6...T1
T70
T70T70
T70°C
CC
CMaximum surface temperature of the signal converter housing without dust coating at
ambient temperature 65°C / 149°F and product temperature 65°C / 149°F
Gb
GbGb
Gb EPL, suitable for zone 1
Db
DbDb
Db EPL, suitable for zone 21

2 DEVICE DESCRIPTION
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2.7 Ambient temperature / temperature classes
Due to the influence of the product temperature, variable area flowmeters with built-in electrical
equipment (electric variants) are not assigned to any fixed temperature class.
In fact, the temperature class of a device is a function of the temperature of both the product and
the environment. The classification is outlined in the following tables.
The tables take into account the following parameters:
•Maximum value P
i
•Ambient temperature T
amb
•Product temperature T
m
•Nominal size DN
•Standard or high temperature version (HT)
•Standard or heating jacket version
•Heat resistance of the connecting cable
The permitted ambient temperature range is indicated on the nameplate; depending on the
device version it is T
amb
= -40...+60°C / -40...+140°F or T
amb
= -20...+60°C / -4...+140°F.
The minimum product temperature is -40°C/-40°F.
For certain device versions, lower values apply due to differing boundary conditions (e.g. liner
materials). Here the user should consult the technical data sheet. The maximum values stated in
the handbook for non-explosion protected device versions must also not be exceeded for
explosion-protected versions.
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 manufacturer's
installation instructions.
• 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.
For this purpose, the variant with a projecting indicator (HT version) is preferable.
• For device versions with a heating jacket the temperature of the heating medium does not
exceed the maximum permissible product temperature.
INFORMATION!
The following conditions must be met for all versions:
• Standard connecting cable, temperature resistance min. 70 ° C / 158 ° F.
• Heat-resistant connecting cable, temperature resistance min. 90 ° C / 194 ° F.

DEVICE DESCRIPTION 2
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Maximum permissible temperatures when using a heat resistant connecting cable
Maximum permissible temperatures when using a standard connecting cable
Maximum permissible product temperature T
m
[°C]
Heating jacket TK T6 T5 T4 T3 T2, T1
without with HT
version
T
amb
[°C] 
≤60 ≤65 ≤65 ≤60 ≤65 ≤60 ≤65
DN15
DN25
DN50
DN15
DN25 85 100 135 200 175 200 175
x85 100 135 200 200 300 300
DN80
DN100 DN50 DN80 85 100 130 185 165 185 165
x85 100 135 200 200 300 300
Maximum permissible product temperature T
m
[°F]
Heating jacket TK T6 T5 T4 T3 T2, T1
without with HT
version
T
amb
[°F] 
≤140 ≤149 ≤149 ≤140 ≤149 ≤140 ≤149
DN15
DN25
DN50
DN15
DN25 185 212 275 392 347 392 347
x185 212 275 392 392 572 572
DN80
DN100 DN50 DN80 185 212 275 365 329 365 329
x185 212 275 392 392 572 572
Maximum permissible product temperature T
m
[°C]
Heating jacket TK T6 T5 T4 T3 T2, T1
without with HT
version
T
amb
[°C] 
≤60 ≤60 ≤65 ≤60 ≤65 ≤60 ≤65 ≤60 ≤65
DN15
DN25
DN50
DN15
DN25 85 100 75 105 75 105 75 105 75
x85 100 95 135 95 175 95 175 95
DN80
DN100 DN50 DN80 85 90 75 90 75 90 75 90 75
x85 100 90 135 90 155 90 155 90
Maximum permissible product temperature T
m
[°F]
Heating jacket TK T6 T5 T4 T3 T2, T1
without with HT
version
T
amb
[°F] 
≤140 ≤140 ≤149 ≤140 ≤149 ≤140 ≤149 ≤140 ≤149
DN15
DN25
DN50
DN15
DN25 185 212 167 221 167 221 167 221 167
x185 212 203 275 203 347 203 347 203
DN80
DN100 DN50 DN80 185 194 167 194 167 194 167 194 167
x185 212 194 275 194 311 194 311 194

2 DEVICE DESCRIPTION
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Reference point observation
Reference point observationReference point observation
Reference point observation
The permissible product and ambient temperatures may be exceeded or undershot as long as
the permissible temperature range of the reference point of the display is not exceeded. The
following table contains the permissible maximum values at the reference point. Note:
•Reference point is the connection of the equipotential bonding conductor of the M40 indicator.
•The temperatures at the reference point are to be determined in the most unfavourable
operating situation.
•The required measuring uncertainty is max. 2 K.
•Measuring conditions and results are to be permanently recorded in a suitable format.
•The measuring unit should be insulated properly.
Maximum permissible temperatures at reference point
The permissible ambient temperature range is indicated on the nameplate; depending on the
device version it is T
amb
= -40...+60°C / -40...+140°F or T
amb
= -20...+60°C / -4...+140°F.
Maximum permissible temperature at the reference
point T
Ref
[°C]
Heating jacket TK T6...T1 T6 T5...T1
without with T
Connecting cable
[°C] standard (70°C) heat-resistant (90°C)
DN15
DN25
DN50
DN80
DN100
DN15
DN25
DN50
DN80
64 74 84
Maximum permissible temperature at the reference
point T
Ref
[°F]
Heating jacket TK T6...T1 T6 T5...T1
without with T
Connecting cable
[°F] standard (158°F) heat-resistant (194°F)
DN15
DN25
DN50
DN80
DN100
DN15
DN25
DN50
DN80
147 165 183
WARNING!
The permissible lowest temperature at the reference point must not fall below the lowest limit
value of the ambient temperature.