Instruction and Operation Manual
for ATEX Approved Load Cells
Table of contents
0. |
Valid for Load Cells |
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1 . Preamble |
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2 . Equipment Function |
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2.1 |
Details |
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2.2 |
Connection of the Standard Version |
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2.2.1 Examples of suitable circuits with approved safety barriers : |
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2.3 |
Connections of the 6-wire Version |
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2.4 |
Advice for Interconnections |
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2.5 |
Coding of the Load Cells |
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2.6 |
Reference notes concerning electrostatics |
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2.7 |
Special notes to the relative inductance and capacities of cables within intrinsically safe circuits |
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3. |
Designation |
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3.1 |
Standard Label |
3.2 Categorie - Designation |
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Commissioning and Installation |
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5. |
Usage |
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6. |
Maintenance |
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7. |
Repair |
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8. |
Waste Disposal |
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9. |
EC-Declaration of Conformity |
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10. ECType Examination Certificate |
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issued |
checked |
released |
Date |
30.06.2004 |
11.11.2010 |
11.11.2010 |
Signatures |
Greulich |
Kämper |
Dr. Achenbach |
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Last revision: 24.10.2014 |
Revision: 9.5 |
Page 1 / 12 |
Date of 1st issue: 03.06.2002 |
Instruction and Operation Manual
for ATEX Approved Load Cells
0. Valid for Load Cells
BK2, PC1, PC2, PC2H, PC6, PC12, PC22, PC42, PC46, PC60, PCB, SB2, SB4, SB5, SB6, SB8, SB14, SLB, ZLB, RC1, RC2, RC3, UB1, UB5, UB6, ULB
1 . Preamble
This manual covers only the “Ex” relevant aspects.
2 . Equipment Function
Flintec load cells are designed to be used in various kinds of industrial scales and meet the most stringent accuracy requirements. Certifications have been obtained from Weights & Measures Authorities worldwide. These load cells are available with different maximum capacities and include accuracy classifications according to OIML R 60 and / or NTEP.
They offer stainless steel or aluminium construction sealed by welding or improved potting.
This makes them suitable for use in tough industrial environments – they are designed to withstand shock and fatigue loading.
The load cells can be used in all hazardous areas. The basic structure is always the same.
All standard equipment is provided with a 4-wire shielded conductor cable; equipment with the coding extension –6w is provided with a 6-wire shielded conductor cable.
(See Chapter 2.5 Coding of Load Cells)
2.1 Details
The following table shows the relationship between maximum total power Pi and maximum ambient temperature.
Temperature class / coding |
Ui = 30 V, Pi = 4 W |
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T6 (gas) |
-40°C ≤ Ta ≤ 45°C |
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T5 (gas) |
-40°C ≤ Ta ≤ 60°C |
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T100°C (dust) |
-40°C ≤ Ta ≤ 60°C |
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2.2 Connection of the Standard Version
Supply circuit: |
green (+) and black (-) |
Signal circuit: |
white (+) and red (-) |
Shield |
yellow and / or metallic |
The intrinsically safe circuit including the load cells must be built up with approved safety barriers or switch amplifiers, matching the connected weighing indicator.
Last revision: 24.10.2014 |
Revision: 9.5 |
Page 2 / 12 |
Date of 1st issue: 03.06.2002 |
Instruction and Operation Manual
for ATEX Approved Load Cells
2.2.1 Examples of suitable circuits with approved safety barriers :
Warning: The displayed examples are verified for ignition protection.
The specialist who installs the equipment must take responsibility
for proper operation in combination with various measuring equipment .
Example : With safety barriers for single-ended supply
Wiring diagrams of different circuit examples are available on request
2.3 Connections of the 6-wire Version
Supply circuit: |
green (+) and black (-) |
Signal circuit: |
white (+) and red (-) |
Sense circuit: |
blue (+) and brown (-) |
Shield: |
yellow and / or metallic |
The intrinsically safe circuit including the load cells must be built up with approved safety barriers or switch amplifiers, matching the connected weighing indicator.
Last revision: 24.10.2014 |
Revision: 9.5 |
Page 3 / 12 |
Date of 1st issue: 03.06.2002 |
Instruction and Operation Manual
for ATEX Approved Load Cells
2.4 Advice for Interconnections
a)Follow and respect the formation-regulations of the application-country. E.g. in Germany follow the regulations EN 60079-14 and EN 61241-14.
b)It is ONLY permitted to use approved safety barriers or switch amplifiers for explosive-areas. In Europe, it is a requirement to have an EC-Type Examination Certificate from a nominated certifying body for the Zones 0 / 1 / 20 / 21.
c)The rated power, Po ,of all excitation devices must be equal to or less than the power, Pi, of one load cell.
d)The excitation voltage Uo must be equal to or less than the voltage Ui of one load cell.
e)The current, Io ,of all excitation devices must be equal to or less than the current, Ii ,of one load cell.
f)To ensure a potential equalisation with -6w versions, a ground connection between the load cell housing and the safety barrier’s ground connector is required. In these installations, the shield of the connection cable is connected to ground potential at both ends.
g)On usual deliveries up to 10 meters, the inductance and capacitance per unit length of the connection cables is negligible.
2.5 Coding of the Load Cells
The load cells have to be marked according to the following scheme:
AAA-BBB-CCC-DDEF-ZZ, e.g. SB8-100kg-C3-6wsc-12
AAA= Load cell type
BBB= Load cell maximum capacity
CCC= Accuracy class
DD |
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without marking = 4-wire; 6w = 6-wire |
E= without marking = screen of cable not connected to load cell body, s = screen of cable connected to load cell body
F= without marking = not coated, c = coated
ZZ |
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Cable length in plain text (in meter) if the load cell cable at delivery is longer than 10m |
2.6 Reference notes concerning electrostatics
The load cells can be covered with a non-conductive protective coating as corrosion prevention. In the type designation code the load cells are marked as "c" in the last position (F).
The free projected surface must not be larger than indicated in the following table after mounting the load cells (types ***-*** ***-** *c) and propagating brush discharges must be avoided.
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Max. free projected surface |
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Used in: |
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IIA |
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IIB |
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IIC |
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Zone 0 |
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50 cm² |
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25 cm² |
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4 cm² |
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Zone 1 / |
2 |
100 cm² |
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100 cm² |
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20 cm² |
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Zone 20 |
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No limitation of size, |
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but exclusion of |
propagating brush discharges |
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Zone 21 / |
22 |
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If the limiting values of the at maximum tolerable free projected surface cannot be maintained, then mounting can be done by the user (if propagating brush discharges can be eliminated) and he can point to this risk on an ESDwarning label (Clean wet only !) on site and in his explosion protection document. In Zone 2 the installation contractor may permit larger free surfaces on his own responsibility, in accordance with the EX regulations
Last revision: 24.10.2014 |
Revision: 9.5 |
Page 4 / 12 |
Date of 1st issue: 03.06.2002 |
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