Maintenance - Zenit MAI Manual De Uso

In case of installations of EXPLOSION-PROOF pumps, you must install at least 2 float switches with certification ATEX
(start ant stop) and suitable for the room where they have to work.
The electric pumps are suitable for the installation in ATEX room and have this mark:
Make sure the switching from stop to start happens only and exclusively if both float switches are in the position indicated in Fig. 1.
Make sure the switching from start to stop happens only and exclusively if both float switches are in the position indicated in Fig. 2.
Make sure the switching here above happens when the electric pump is totally submerged (Fig. 2).
The electric connections of the float switches must be able to guarantee the stop of the electric pump, in case of bad working of the
float switch.
Fig. 1

5 . MAINTENANCE

Before inspection and maintenance operations, carefully read and apply the safety procedures indicated in paragraphs 1.2 and 1.3.
WARNING: do not tamper the explosion-proof casing and cable clamps of any explosion-proof electric pump.
Furthermore, you are reminded that all maintenance, cleaning, installation or routine checks requiring work to be carried out
on the device, must be performed safely and in compliance with the safe set-up procedure.
The safe set-up procedure provides for the following:
- All the operations must be carried out in a safe place, away from any potentially explosive environments.
- All primary sources of electricity must be removed.
- Wait until all the parts of the equipment have cooled to an acceptable temperature.
To ensure the electric pump a long, constant working life, the user is required to carry out regular checks, cleaning (to prevent the
build up of dust, as prescribed in norm) maintenance and the replacement of any worn parts.
It is advisable to perform inspections on a monthly basis, or every 500-600 working hours.
- check that the power supply voltage corresponds to the values indicated on the data plate;
- check that noise and vibrations are at their original levels;
- for three-phase motors, use amperometric pincers to check the absorbance rates of the three phases are balanced and do not
exceed the specifications stated on the plate.
Fig. 2 - 2/a show the blow-up of the electric pump.
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Fig. 2