KROHNE H250 M40 Series Wiring diagram

Equipment category II 2G and II 2D, EPL Gb and Db
in protection type intrinsic safety "i"
H250 M40
H250 M40H250 M40
H250 M40 Supplementary instructions
Supplementary instructionsSupplementary instructions
Supplementary instructions
© KROHNE 02/2015 - 4001481102 - MA H250/M40-Exi--II2GD-AD R02 en

CONTENTS
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H250 M40
1 Safety instructions 3
1.1 General notes ................................................................................................................... 3
1.2 EC conformity ................................................................................................................... 3
1.3 Approval according to the IECEx scheme ........................................................................ 3
1.4 Security information......................................................................................................... 4
2 Device description 5
2.1 Device description ............................................................................................................ 5
2.2 Description code............................................................................................................... 5
2.3 Marking............................................................................................................................. 6
2.4 Flammable products ........................................................................................................ 7
2.5 Device category ................................................................................................................ 7
2.6 Protection types................................................................................................................ 8
2.7 Ambient temperature / temperature classes.................................................................. 9
2.8 Surface temperature for equipment category II 2D ...................................................... 15
2.9 Electrical data................................................................................................................. 16
3 Installation 17
3.1 Installation...................................................................................................................... 17
4 Electrical connections 18
4.1 General notes ................................................................................................................. 18
4.2 Power supply .................................................................................................................. 18
4.3 Inputs/outputs ................................................................................................................ 18
4.4 Grounding and equipotential bonding............................................................................ 18
5 Operation 19
5.1 Start-up........................................................................................................................... 19
5.2 Operation ........................................................................................................................ 19
5.3 Electrostatic charge .......................................................................................................19
6 Service 20
6.1 Maintenance ................................................................................................................... 20
6.2 Dismantling .................................................................................................................... 20
7 Notes 21

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 with protection type intrinsic safety "i", equipment category II 2 G and II 2
D, EPL Gb and Db. It completes the installation and operating instructions 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 apply
unchanged unless excluded or superseded by these instructions.
1.2 EC conformity
The manufacturer declares with the EC declaration of conformity, in which the applied standard
is also specified, on his own responsibility conformity with the protection goals of directive
94/9/EC for use in hazardous areas with gas and dust.
The EC declaration of conformity for the equipment category II 2 G and II 2 D is based on the EC
type examination certificate of the Physikalisch Technische Bundesanstalt (PTB):
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 EC type examination certificate can be downloaded from the manufacturer's
website.
1.3 Approval according to the IECEx scheme
Conformity of the variable area flowmeter for use in hazardous areas with gas was tested in
accordance with the IECEx Certification Scheme for Explosive Atmospheres acc. to IEC 60079-0:
2007 and IEC 60079-11: 2006. The number of the IEC 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.
PTB 11 ATEX 2012 X
PTB 11 ATEX 2012 XPTB 11 ATEX 2012 X
PTB 11 ATEX 2012 X
IECEx PTB 11.0069 X
IECEx PTB 11.0069 XIECEx PTB 11.0069 X
IECEx PTB 11.0069 X

1 SAFETY INSTRUCTIONS
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1.4 Security information
Assembly, installation, start-up and maintenance may only be performed by personnel trained in
explosion protection!
CAUTION!
The operator respectively his agent is responsible to follow further standards, directives or laws
if required due to operating conditions or place of installation. This applies particularly for the
use of easy detachable process connections such as SMS or Clamp when measuring flammable
mediums.

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. Depending on the device version, electrical limit switch 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

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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 2-1: Examples of identification plates
1 Meter 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 Manufacturer's website

DEVICE DESCRIPTION 2
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2.4 Flammable products
Atmospheric conditions:
Atmospheric conditions:Atmospheric conditions:
Atmospheric conditions:
An explosive atmosphere is a mixture of air and flammable gases, vapours, mists or dusts under
atmospheric conditions. It is defined by the following values T
atm
= -20...+60°C /
-4...+140°F and P
atm
= 0.8...1.1 bar. Outside of this range, 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 directive 94/9/EC (ATEX) –regardless of the zone assignment
–is fundamentally not applicable due to the lack of key safety data for the interior of the
measuring section.
2.5 Device category
Variable area flowmeters are designed in accordance with EN 60079-0 and EN 60079-11 in
category II 2 G and EPL Gb for use in zone 1.
Depending on the device version, variable area flowmeters are also designed in
category II 2 D and EPL Db for use in zone 21.
The inside of the measuring unit is also permitted 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-liner, nonconductive) the min. conductivity of the medium must be 10
-8
S/m, in order to
avoid the electrostatic charge.
INFORMATION!
Definition of zone 1 acc. 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 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.

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2.6 Protection types
The variable area flowmeter is designed with protection type intrinsic safety "i" acc. to EN 60079-
11.
The identification for equipment category II 2 G and EPL Gb is:
II 2G Ex ia IIC T6...T2 Gb or II 2G Ex ia IIB T6...T2 Gb
II 2G Ex ia IIC T6...T2 Gb or II 2G Ex ia IIB T6...T2 GbII 2G Ex ia IIC T6...T2 Gb or II 2G Ex ia IIB T6...T2 Gb
II 2G Ex ia IIC T6...T2 Gb or II 2G Ex ia IIB T6...T2 Gb
The additional identification of the version for the equipment category II 2 D and EPL Db is:
II 2D Ex ia IIIC T85
II 2D Ex ia IIIC T85II 2D Ex ia IIIC T85
II 2D Ex ia IIIC T85°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
IIB
IIBIIB
IIB Gas group, suitable for gas groups IIB and IIA
T6...T2
T6...T2T6...T2
T6...T2 Temperature class range, suitable for temperature classes T6 ... T1
Gb
GbGb
Gb EPL, suitable for zone 1
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 explosion 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
T85
T85T85
T85°C
CC
CMaximum surface temperature at 65°C ambient temperature
Db
DbDb
Db EPL, suitable for zone 21
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.

DEVICE DESCRIPTION 2
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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. The temperature
class of these devices is rather a function of the product temperature and ambient temperature
that is present and the specific device version. The classification is outlined in the following
tables.
The tables take into account the following parameters:
•installed equipment
•Maximum values I
i
and P
i
for K1, K2
•Ambient temperature T
amb
•Product temperature T
m
•Nominal DN
•Standard or high temperature version (HT)
•Standard or heating jacket version
•Heat resistance of the connecting cable
When using more than one installed equipment, the data of the most unfavourable equipment
should be used.
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.
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.

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Using a heat resistant connecting cable
1Maximum value of the product temperature for the use of a standard connecting cable. For
higher product temperatures a connecting cable with a temperature resistance of 90°C / 194°F is
required.
HT version - high-temperature version with projecting indicator
The permitted ambient temperature range is indicated on the nameplate; depending on the
device version it is Tamb = -40...+65°C / -40...+149°F or Tamb = -25...+65°C / -13...+149°F.
The minimum product temperature is -40°C / -40°F.
Temperature table in °C
Heating jacket T
m
1
without with HT-version T
amb
≤40 T
amb
≤60 T
amb
≤65
DN15, DN25, DN50 DN15, DN25 220 105 75
x - 175 95
DN80, DN100 DN50, DN80 165 90 75
x - 155 90
Temperature table in °F
Heating jacket T
m
1
without with HT-version T
amb
≤104 T
amb
≤140 T
amb
≤149
DN15, DN25, DN50 DN15, DN25 428 221 167
x - 347 203
DN80, DN100 DN50, DN80 329 194 167
x - 311 194

DEVICE DESCRIPTION 2
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Maximum permitted product temperature in °C
Maximum permissible product temperature T
m
[°C]
Heating
jacket
TK T6 T5 T4 T3 T2, T1
withou
t
with HT
version
T
amb
[°C] 
≤40 ≤60 ≤65 ≤60 ≤65 ≤40 ≤60 ≤65 ≤40 ≤60 ≤65
ESK4
ESK4ESK4
ESK4
DN15
DN25
DN50
DN15
DN25 85 100 90 135 135 200 160 140 235 160 140
x85 100 100 135 135 200 200 200 300 300 270
DN80
DN100 DN50 DN80 85 100 85 135 130 200 150 130 220 150 130
x85 100 100 135 135 200 200 200 300 300 255
ESK4-T
ESK4-TESK4-T
ESK4-T
DN15
DN25
DN50
DN15
DN25 85 90 70 135 120 200 140 120 220 140 120
x85 100 85 135 135 200 200 200 300 290 225
DN80
DN100 DN50 DN80 85 85 70 130 115 200 130 115 200 130 115
x85 100 80 135 135 200 200 200 300 270 215
ESK4-FF / ESK4-PA
ESK4-FF / ESK4-PAESK4-FF / ESK4-PA
ESK4-FF / ESK4-PA
DN15
DN25
DN50
DN15
DN25 70 60 not admissi
ble
135 125 200 150 125 235 150 125
x85 60 135 135 200 200 200 300 300 240
DN80
DN100 DN50 DN80 65 60 135 120 200 140 120 220 140 120
x85 60 135 135 200 200 200 300 300 225
K1/K2 - 64 mW
K1/K2 - 64 mWK1/K2 - 64 mW
K1/K2 - 64 mW
DN15
DN25
DN50
DN15
DN25 85 100 100 135 135 200 200 180 290 205 180
x85 100 100 135 135 200 200 200 300 300 300
DN80
DN100 DN50 DN80 85 100 100 135 135 200 185 170 260 185 170
x85 100 100 135 135 200 200 200 300 300 300
K1/K2 (I7S23,5-N / SC3,5-N0-Y) - 169 mW
K1/K2 (I7S23,5-N / SC3,5-N0-Y) - 169 mWK1/K2 (I7S23,5-N / SC3,5-N0-Y) - 169 mW
K1/K2 (I7S23,5-N / SC3,5-N0-Y) - 169 mW
DN15
DN25
DN50
DN15
DN25 not admissible 105 80 200 105 80 210 105 80
x135 115 200 200 115 300 200 115
DN80
DN100 DN50 DN80 105 80 195 105 80 195 105 80
x135 110 200 190 110 300 190 110
K1/K2 (SJ3,5-SN or SJ3,5-S1N) - 169 mW
K1/K2 (SJ3,5-SN or SJ3,5-S1N) - 169 mWK1/K2 (SJ3,5-SN or SJ3,5-S1N) - 169 mW
K1/K2 (SJ3,5-SN or SJ3,5-S1N) - 169 mW
DN15
DN25
DN50
DN15
DN25 not admissible 135 135 200 195 170 295 195 170
x135 135 200 200 200 300 300 300
DN80
DN100 DN50 DN80 135 135 200 180 160 275 180 160
x135 135 200 200 200 300 300 300
R1/R2 (Reed SPST)
R1/R2 (Reed SPST)R1/R2 (Reed SPST)
R1/R2 (Reed SPST)
DN15
DN25
DN50
DN15
DN25 x85 100 100 135 135 200 200 150 300 235 150
DN80
DN100 DN50 DN80 x85 100 100 135 135 200 200 145 300 220 145

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Maximum permitted product temperature in °F
Maximum permitted product temperature T
m
[°F]
Heating
jacket
TK T6 T5 T4 T3 T2, T1
withou
t
with HT
version
T
amb
[°F] 
≤104 ≤140 ≤149 ≤140 ≤149 ≤104 ≤140 ≤149 ≤104 ≤140 ≤149
ESK4
ESK4ESK4
ESK4
DN15
DN25
DN50
DN15
DN25 185 212 194 275 275 392 320 284 455 320 284
x185 212 212 275 275 392 392 392 572 572 518
DN80
DN100 DN50 DN80 185 212 185 275 266 392 302 266 428 302 266
x185 212 212 275 275 392 392 392 572 572 491
ESK4-T
ESK4-TESK4-T
ESK4-T
DN15
DN25
DN50
DN15
DN25 185 194 158 275 248 392 284 248 428 284 248
x185 212 185 275 275 392 392 392 572 554 437
DN80
DN100 DN50 DN80 185 185 158 266 239 392 266 239 392 266 239
x185 212 176 275 275 392 392 392 572 518 419
ESK4-FF / ESK4-PA
ESK4-FF / ESK4-PAESK4-FF / ESK4-PA
ESK4-FF / ESK4-PA
DN15
DN25
DN50
DN15
DN25 158 140 not admissi
ble
275 257 392 302 257 455 302 257
x185 140 275 275 392 392 392 572 572 464
DN80
DN100 DN50 DN80 149 140 275 248 392 284 248 428 284 248
x185 140 275 275 392 392 392 572 572 437
K1/K2 - 64 mW
K1/K2 - 64 mWK1/K2 - 64 mW
K1/K2 - 64 mW
DN15
DN25
DN50
DN15
DN25 185 212 212 275 275 392 392 356 554 401 356
x185 212 212 275 275 392 392 392 572 572 572
DN80
DN100 DN50 DN80 185 212 212 275 275 392 365 338 500 365 338
x185 212 212 275 275 392 392 392 572 572 572
K1/K2 (I7S23,5-N / SC3,5-N0-Y) - 169 mW
K1/K2 (I7S23,5-N / SC3,5-N0-Y) - 169 mWK1/K2 (I7S23,5-N / SC3,5-N0-Y) - 169 mW
K1/K2 (I7S23,5-N / SC3,5-N0-Y) - 169 mW
DN15
DN25
DN50
DN15
DN25 not admissible 221 176 392 221 176 410 221 176
x275 239 392 392 239 572 392 239
DN80
DN100 DN50 DN80 221 176 383 221 176 383 221 176
x275 230 392 374 230 572 374 230
K1/K2 (SJ3,5-SN or SJ3,5-S1N) - 169 mW
K1/K2 (SJ3,5-SN or SJ3,5-S1N) - 169 mWK1/K2 (SJ3,5-SN or SJ3,5-S1N) - 169 mW
K1/K2 (SJ3,5-SN or SJ3,5-S1N) - 169 mW
DN15
DN25
DN50
DN15
DN25 not admissible 275 275 392 383 338 563 383 338
x275 275 392 392 392 572 572 572
DN80
DN100 DN50 DN80 275 275 392 356 320 527 356 320
x275 275 392 392 392 572 572 572
R1/R2 (Reed SPST)
R1/R2 (Reed SPST)R1/R2 (Reed SPST)
R1/R2 (Reed SPST)
DN15
DN25
DN50
DN15
DN25 x185 212 212 275 275 392 392 305 572 460 305
DN80
DN100 DN50 DN80 x185 212 212 275 275 392 392 295 572 435 295

DEVICE DESCRIPTION 2
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Maximum permitted product temperatures for painted measuring units in °C
Maximum permitted product temperatures for painted measuring units in °F
Maximum permissible product temperature T
m
[°C]
Heating jacket TK T6 T5 T4 ... T1
without with HT version T
amb
[°C] ≤40 ≤60 ≤65 ≤60 ≤65
DN15...
DN100
DN15...
DN80
With / none
ESK4 / ESK4-T 40 65 65 65 65
ESK4-FF / ESK4-PA 40 60 not
admissible 65 65
K1/K2 - 64 mW / R1/R2 40 65 65 65 65
K1/K2 (I7S23,5-N / SC3,5-N0-Y) - 169 mW not
admissible not admissible 65 65
K1/K2 (SJ3,5-SN bzw. SJ3,5-S1N) - 169 mW not
admissible not admissible 65 65
Maximum permitted product temperature T
m
[°F]
Heating jacket TK T6 T5 T4 ... T1
without with HT version T
amb
[°F] ≤104 ≤140 ≤149 ≤140 ≤149
DN15...
DN100
DN15...
DN80
With / none
ESK4 / ESK4-T 104 149 149 149 149
ESK4-FF / ESK4-PA 104 140 not
admissible 149 149
K1/K2 - 64 mW / R1/R2 104 149 149 149 149
K1/K2 (I7S23,5-N / SC3,5-N0-Y) - 169 mW not
admissible not admissible 149 149
K1/K2 (SJ3,5-SN bzw. SJ3,5-S1N) - 169 mW not
admissible not admissible 149 149

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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. 2K.
•Measuring conditions and results are to be permanently recorded in a suitable format.
•The measuring unit should be insulated properly.
•At temperatures above 70°C / 158°F, a heat-resistant cable must be used.
Maximum permitted temperatures at reference point of indicator in °C
Design of
indicator
Component Limit switch P
i
[mW]
Permitted temperature range at reference point
T [°C] according to temperature class
TK T6 T5 T4 ... T1
M40./../K. SC3,5-NO-Y 64 -20 ... +65 -20 ... +80 -20 ... +90
169 -20 ... +37 -20 ... +52 -20 ... +72
SJ3,5-SN 64 -40 ... +66 -40 ... +81 -40 ... +90
169 -40 ... +42 -40 ... +57 -40 ... +86
SJ3,5-S1N 64 -20 ... +66 -20 ... +81 -20 ... +90
169 -20 ... +42 -20 ... +57 -20 ... +86
I7S23,5-N 64 -40 ... +70 -40 ... +85 -40 ... +90
169 -40 ... +52 -40 ... +67 -40 ... +90
M40./../R. Reed SPST 1000 -40 ... +65 -40 ... +65 -40 ... +65
M40./../ESK4/K. SC3,5-NO-Y 64 -20 ... +55 -20 ... +70 -20 ... +80
169 -20 ... +33 -20 ... +48 -20 ... +68
SJ3,5-SN 64 -40 ... +55 -40 ... +70 -40 ... +80
169 -40 ... +38 -40 ... +53 -40 ... +80
SJ3,5-S1N 64 -20 ... +55 -20 ... +70 -20 ... +80
169 -20 ... +38 -20 ... +53 -20 ... +80
I7S23,5-N 64 -40 ... +55 -40 ... +70 -40 ... +80
169 -40 ... +48 -40 ... +63 -40 ... +80
M40./../ESK4/R. Reed SPST 1000 -40 ... +55 -40 ... +65 -40 ... +65
M40./../ESK4 ESK4 --- -40 ... +55 -40 ... +70 -40 ... +80
M40./../ESK4-T ESK4 and I/O modul --- -40 ... +52 -40 ... +67 -40 ... +77
M40./../ESK4-FF ESK4 and ESK4-FF --- -40 ... +36 -40 ... +51 -40 ... +76
M40./../ESK4-PA ESK4 and ESK4-PA ---

DEVICE DESCRIPTION 2
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Maximum permitted temperatures at reference point of indicator in °F
2.8 Surface temperature for equipment category II 2D
For use in areas with flammable dust it should be noted that the indicated maximum surface
temperature of T85°C at an ambient temperature of 65°C / 149°F and a product temperature of
85°C / 185°F is valid without a dust coating. For higher product temperatures the maximum
surface temperature is defined by the product.
Design of
indicator
Component Limit switch P
i
[mW]
Permitted temperature range at reference point
T [°F] according to temperature class
TK T6 T5 T4 ... T1
M40./../K. SC3,5-NO-Y 64 -4 ... +149 -4 ... +176 -4 ... +194
169 -4 ... +99 -4 ... +126 -4 ... +162
SJ3,5-SN 64 -40 ... +151 -40 ... +178 -40 ... +194
169 -40 ... +108 -40 ... +135 -40 ... +187
SJ3,5-S1N 64 -4 ... +151 -4 ... +178 -4 ... +194
169 -4 ... +108 -4 ... +135 -4 ... +187
I7S23,5-N 64 -40 ... +158 -40 ... +185 -40 ... +194
169 -40 ... +126 -40 ... +153 -40 ... +194
M40./../R. Reed SPST 1000 -40 ... +149 -40 ... +149 -40 ... +149
M40./../ESK4/K. SC3,5-NO-Y 64 -4 ... +131 -4 ... +158 -4 ... +176
169 -4 ... +91 -4 ... +118 -4 ... +154
SJ3,5-SN 64 -40 ... +131 -40 ... +158 -40 ... +176
169 -40 ... +100 -40 ... +127 -40 ... +176
SJ3,5-S1N 64 -4 ... +131 -4 ... +158 -4 ... +176
169 -4 ... +100 -4 ... +127 -4 ... +176
I7S23,5-N 64 -40 ... +131 -40 ... +158 -40 ... +176
169 -40 ... +118 -40 ... +145 -40 ... +176
M40./../ESK4/K. Reed SPST 1000 -40 ... +131 -40 ... +149 -40 ... +149
M40./../ESK4 ESK4 --- -40 ... +131 -40 ... +158 -40 ... +176
M40./../ESK4-T ESK4 and I/O modul --- -40 ... +126 -40 ... +153 -40 ... +171
M40./../ESK4-FF ESK4 and ESK4-FF --- -40 ... +97 -40 ... +124 -40 ... +169
M40./../ESK4-PA ESK4 and ESK4-PA ---

2 DEVICE DESCRIPTION
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2.9 Electrical data
Built-in equipment for the variable area flowmeter may only be connected to separate
intrinsically safe circuits with the following maximum values:
Electrical equipment Nominal voltage Nominal current
Limit switch K1 / K2 8VDC ≤1 / ≥3mA
reed switches R1 / R2 3 ... 30 VDC 0,1 ... 100 mA
Signal output ESK4 14 ... 30 VDC 4...20mA with HART
®
communication
Switching output ESK4-T OC Output 8 ... 30 VDC 1...100 mA
Switching output ESK4-T NAMUR Output 8VDC ≤1 / ≥3mA
Signal input ESK4-T input 8 ... 30 VDC ≤2 mA
ESK4-FF Foundation Fieldbus
transmitter 1
9 ... 24 VDC 16 mA
ESK4-PA Profibus transmitter 2 9 ... 24 VDC 16 mA
1Further information and instructions for operation of the ESK4-FF transmitter are provided in separate supplementary
instructions.
2Further information and instructions for operation of the ESK4-PA Profibus transmitter are provided in separate sup-
plementary instructions.
Maximum values
Installed equipment U
i
[V] Ii[mA] P
i
[mW] C
i
[nF] L
i
[μH]
ESK4 30 130 1000 ~ 0 10
ESK4-T (I/O-modul) 30 130 1000 10 ~ 0
ESK4-PA / ESK4 FF 1 24 380 5320 ~ 0 ~ 0
I7S23,5-N / SC3,5-N0 16 25 64 150 150
16 52 169 150 150
SJ3,5-SN / SJ3,5-S1N 16 25 64 30 100
16 52 169 30 100
Reed SPST 30 100 1000 ~ 0 ~ 0
1FISCO field device
WARNING!
Also, when operating the variable area flowmeter outside of the hazardous area, the connection
must be made to an intrinsically safe circuit. When connecting to non-intrinsically safe circuits,
there is a risk of damage to the safety-defining components.

INSTALLATION 3
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3.1 Installation
Installation and setup must be carried out according to the applicable installation installation
standards (e.g. EN 60079-14) by qualified personnel trained in explosion protection. The
information given in the Installation and Operation Instructions and the Supplementary
Installation and Operation Instructions must always be observed.
Variable area flowmeters must be installed in such a way that
•There is no danger from mechanical impact effects.
•There are no external forces affecting the indicator part.
•The device is accessible for any visual inspections that are necessary, and can be viewed from
all sides.
•The nameplate is clearly visible.
•It can be operated from a location with secure footing.
Take special note of the installation position for the H250/H/... with horizontal flow
direction:
In order to comply with thermal parameters and measuring accuracy, flowmeters for horizontal
installation are to be installed in the pipeline so that the display is located on the side of the
measuring tube. The maximum product and ambient temperatures indicated as well as the
measuring accuracy are based on lateral installation of the display.
CAUTION!
The manufacturer is not liable for any damage resulting from improper use or use other than the
intended purpose. This applies in particular to hazards due to insufficient corrosion resistance
and suitability of the materials in contact with product.

4 ELECTRICAL CONNECTIONS
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4.1 General notes
The built-in equipment is connected electrically in the indication unit. The circuits are designed
in protection type "intrinsically safe" and galvanically isolated from ground (test voltage ≥
500 V
eff
).
The connecting cables should be selected according to the applicable installation standards (e.g.
EN 60079-14) and the maximum operating temperature. Ensure that no residual current can
form between separate intrinsically safe signal circuits.
•The connecting cables must be fixed and laid so they are sufficiently protected against
damage.
•All cores that are not used must be securely connected to the ground potential of the
hazardous area or carefully insulated against each other and against ground (test voltage ≥
500 V
eff
).
•Lay cables so as to ensure that there is sufficient distance between surfaces of the
measuring unit and the connecting cable.
•Supplied blind plugs / cable entries guarantee protection against foreign objects and water
(protection category) IP66 / 67 according to EN 60529 in the temperature range of
T
amb
= -40...+100°C / -40...+212°F.
•The outer diameter of the connecting cable must be within the sealing range of the cable
entry (8...13 mm / 0.31...0.51").
•Unused cable entries are to be closed (>IP66 / 67).
Ensure that the seals and cut seals are tight.
4.2 Power supply
The variable area flowmeter does not require a separate power supply. The required supply for
the built-in electronics is provided via the 4...20mA current output and the bus connection.
4.3 Inputs/outputs
The terminal assignment of the built-in electrical equipment is described in the Standard
Installation and Operation Instructions. The variable area flowmeter signal circuits may only be
connected to certified intrinsically safe slave units or circuits. For more information see chapter
"Electrical data"
4.4 Grounding and equipotential bonding
If the device is not sufficiently electrostatically grounded via the process cables, an additional
earth connection must be established using the ground terminal. The ground terminal on the
gate of the cable entry of the display guarantees an electrostatic connection of the device and
complies with the requirements of an equipotential bonding connection.
Any existing cable shields should be connected to earth according to applicable installation
regulations (EN 60079-14). A terminal connection in the terminal compartment permits a short
way earthing of the cable shields.

OPERATION 5
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5.1 Start-up
Start-up is only permitted when the variable-area flowmeter:
•is correctly installed in the system and connected.
•has been checked for the proper state with regard to its installation and connection
requirements.
The user of the system must be have it checked before start-up in compliance with the national
regulations for checks before start-up.
5.2 Operation
Variable area flowmeters must be operated in such a way that they remain within the maximum
and minimum permissible temperatures and pressures and the electrical limit values.
Variable area flowmeters may only be operated if the equipment parts necessary for safety are
effective in the long run, and are not rendered inoperable during operation.
Adjusting the limit switch and operating the display during operation is permitted. To do so,
remove the housing cover. Close the housing cover immediately after the limit switches have
been set or the display operated.
For more information see chapter "Dismantling"
5.3 Electrostatic charge
In order to avoid ignition hazards due to electrostatic charge, variable area flowmeters
may not be used in areas with:
•processes that generate strong charges,
•mechanical friction and cutting processes,
•spraying of electrons (e.g. in the vicinity of electrostatic painting systems).
WARNING!
Ignition risks caused by pressure surges, impact or friction must particularly be avoided when
titanium measuring units are used.
WARNING!
Electrostatic charging of the housing surface by friction must be avoided.
Variable area flowmeters must not be dry cleaned.

6 SERVICE
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6.1 Maintenance
Maintenance work of a safety-relevant nature within the meaning of explosion protection may
only be carried out by the manufacturer, his authorised representative or under the supervision
of authorised inspectors.
To maintain proper condition, regular inspections are required for systems in hazardous areas.
The following checks are recommended:
•Checking the housing, the cable entries and the feed lines for corrosion and/or damage.
•Checking the measuring unit and the piping connections for leakage.
•Checking the measuring unit and the indicator for dust deposits.
•Including the flowmeter in the regular pressure test of the process line.
6.2 Dismantling
Exchanging the built-in equipment
Due to the modular structure of the variable area flowmeters, from a safety point of view it is
possible to exchange the electrical equipment built into the indicator for identical spare parts.
Remove the housing cover to this purpose. The housing cover must be closed immediately after
the spare parts are exchanged. Make sure that the cover seal is properly seated.
Exchanging the entire device
Removal and installation are the responsibility of the operator.
Before disconnecting the electric connecting cable of the device, make sure that all cables
leading to the indication unit are isolated from the ground of the hazardous area. This also
applies to functional earthing conductors (FE) and equipotential bonding conductors (PA).
CAUTION!
There may be a loss of measuring accuracy!
WARNING!
• Pressurized pipes have to be depressurized before removing the measuring unit.
• In the case of environmentally critical or hazardous products, appropriate safety precautions
must be taken with regard to residual liquids in the measuring unit.
• New gaskets have to be used when re-installing the device in the piping.