Index revision : A
8
7116
WARNING : The use of very high voltage increases the risk of sparks. SAMES Technologies
atomizers and high-voltage electrostatic generators are designed to minimise this risk. Although
the HV electrode is the only accessible part, a safety distance of X mm (see table below) must
be observed between the HV parts of the atomizer and all grounded parts.
Authorised spraying distance
The unloading time of the atomizer to reach an energy lower than 350 mJ with a 13m-length high
voltage cable and a 10m-length product hose is 3,3 seconds and 11,3 seconds for an energy lower
than 0,24mJ.
Any installation by isolated system (conductive products) must be equipped with a short-circuiter which
acts in less than two seconds (E < 350mJ in less than two seconds).
In addition, a careful check must be made to ensure that any conducting or semi-conducting part closer
than 2.5 m to the atomizer is correctly grounded.
If it is not, electrical charges capable of causing sparks could build up on it. Operating personnel must
wear anti-static shoes and gloves to avoid this risk.
Each substrate must have a ground resistance of less than or equal to 1 M
Ω
(measurement voltage of
at least 500V). This must be checked regularly.
All conducting enclosures of electrical equipment and conducting components in explosive atmospheres
must be grounded by connecting them to the grounding terminal.
Finally, for the same reasons, the spraying area must have an anti-static floor, such as concrete, metal
duckboard, etc.
It is essential to provide sufficient ventilation in the spraying booths to avoid the build up of inflammable
vapors.
The correct operation of the overcurrent protection (di/dt) must be verified daily. This verification must
be carried out
in a non-explosive atmosphere
, by placing a ground wire near the atomizer electrode
with the atomizer switched on (the operator must be grounded): the control module must switch to the
fault state.
The associated equipment must be located outside hazardous areas, and its operation must be inter-
locked with that of the booth extraction fan. The correct operation of the servocontrol system must be
verified once a week.
Voltage
(kV)
Distance
(mm)
0
100
50
110
60
120
70
135
0
50
100
135
0
50
60
70
D
E
S
006458
Dista
nce (m
m)
Voltage (kV)
Safety distance ”X” as a function of voltage
Non-authorized spraying area
