Integrative notes to the operating manual for magnetic coupling centrifugal pumps conforming to the ATEX 94/9/CE directive TCK... - TBK... – TBAK…
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5.2.1 - Pumps in bare-shaft version
The connection to the grounding must be carried out on one of the fixing screws of the pump to the base which are fitted
to the appropriate round holes or long holes on the pump feet
(Fig. 4)
. In order to enable the electric continuity between
the grounding cable and the pump, the paint in the contact area between the lug for the grounding cable and the pump
foot must be scraped off. The point of preparation is put into evidence by a triangle (yellow), which shows the symbol
(black) of grounding
(Fig. 7)
. If the pump has been correctly installed on the base or the fixed metal frame, the
connection to grounding can also be carried out by fastening the grounding cable to the base or to the frame. However,
the electric continuity between the pump and the grounding cable must be ensured.
5.2.2 - Pumps in close-coupled version
The connection to the grounding must be carried out on one of the linking screws between the pump lantern and the
electric motor
(Fig. 5)
. In order to enable the electric continuity between the grounding cable and the pump, the paint in
the contact area between the lug for the grounding cable and the pump body must be scraped off. The point of
preparation is put into evidence by a triangle (yellow), which shows the symbol (black) of grounding
(Fig. 7)
.
For the pumps of the TCHM series, the connection to grounding is carried out by using the same grounding connection
used for the electric motor, as this specific execution ensures the electric continuity between all parts of the pump.
Fig. 6 – COUPLED PUMP
Fig. 7 – SYMBOL FOR GROUNDING
PLATE
DIRECTION
OF ROTATION
5.2.3 - Pumps coupled to the baseplate
The connection to the grounding must be carried out on the appropriate plate at one side of the base
(Fig. 6)
. In order to
enable the electric continuity between the grounding cable and the pump, the paint in the contact area between the plug
for the grounding cable and the base plate must be scraped off. The point of preparation is put into evidence by a
triangle (yellow), which shows the symbol (black) of grounding
(Fig. 7).
After the connection, use an appropriate
instrument to check the electric continuity between at least three spots of different pump components of conducting
material away from the connection point and the grounding cable. If there is any discontinuity, make sure that all
connections are correctly fixed and have not been tampered with. If the continuity is still insufficient, please contact
POMPETRAVAINI. For cleaning the pump, do not use rags or wool brushes or any other material which facilitates the
generation and accumulation of electrostatic charges which might be the source of sparking.
RESIDUAL RISK: Any incorrect execution of grounding may cause the accumulation of
electrostatic charges on the pump, which may cause sparks and represent an ignition source
due to the potentially explosive atmospheres.
5.2.4 – Carry out of the baseplate
The baseplate where the magnetic coupling pump will be installed must be insulated from possible external sources of
vibrations due to other machine present nearby or vibrations coming from the plant’s pipes connecting the pump. If it is
foreseen that the pump will suffer
from
vibrations induced by external sources must be installed on anti-
vibrations baseplate. The vibrations are dangerous for the magnetic coupling integrity. For further information
look at the paragraph 6.2.
RESIDUAL RISK: if the pump suffer
s from
vibrations
, it
could
cause
impact or
cracking
due to
brittleness of the magnetic coupling components, with consequent
possible development of sparks, high temperatures or seizing of the pump.
This leading to really higher temperature
than the
class Tx for which the pump has been
classified.