Flintec ATEX - Manual (Page 4)

Instruction and Operation Manual
for ATEX Approved Load Cells
Last revision: 24.10.2014 Revision: 9.5 Page 4 / 12 Date of 1st issue: 03.06.2002
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, P
o
,of all excitation devices must be equal to or less than the power, P
i,
of one load cell.
d) The excitation voltage U
o
must be equal to or less than the voltage U
i
of one load cell.
e) The current, I
o
,of all excitation devices must be equal to or less than the current, I
i
,of one load cell.
f) To ensure a potential equalisation with -6w versions, a ground connection between the load cell
housing and the safet y 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 = 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 = 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.
Used in:
Max. free projected surface
IIA IIB IIC
Zone 0 50 cm² 25 cm² 4 cm²
Zone 1 / 2 100 cm² 100 cm² 20 cm²
Zone 20
No limitation of size,
but exclusion of propagating brush discharges
Zone 21 / 22
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 ESD- warning 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