Ground Connection; Thermal Protection; Leakage Detector; Electrical Connection (Standard Version) - Zenit Grey Serie Manual De Primera Instalación

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3.3 Ground connection

• Make sure that the ground system and differential security breaker are present and in good working order.
• Check that the ground conductor is about 150 mm longer than the other conductors so that it will be the last to become disconnected from the
panel in the event of accidental tugs.
The predisposition for the connection of the external earth conductor accepts cables with a cross-sectional area of at least 4 mm².
On -Ex pumps, make sure that an external earth conductor (yellow and green, with cross section at least of 4 mm2) is connected
to the external earth terminal on the pump using a secure cable clamp. Clean the surface of the externa earth connection and
mount the cable clamp.

3.4 Thermal protection

The equipment is equipped with thermal protectors inside the stator windings to shut down the power supply in case of motor overheating.
The standard thermal protection consists of bimetal thermal protectors with nominal switching temperature NST=150°C; as option, bimetallic
protectors can be replaced by PTC thermistors or PT100 sensors.
The thermal protection cables are marked with a label stating "TP" = THERMAL PROTECTION and must be connected to the corresponding
terminals of the control panel.
The connection of the thermal protectors to a control panel is mandatory. The electric panel must be predisposed to guarantee
the shutdown of the motor when the thermal protection intervenes and to avoid the automatic start-up of the pump which must
only be started manually with the intervention of a technician after having fixed the causes of the anomaly.

3.5 Leakage detector

The electric pump can be equipped with a single-electrode leakage detector as an accessory to detect and signal the infiltration of water into the
oil chamber of the mechanical seals (the equipment grounding conductor is used as the return path for the conductive level limit detection).
In the case of detection, take out of service the pump and proceed with maintenance.
The signal cable is marked with a label with the letter S.
For installations with -Ex certified models, the connection to the electric control panel must be carried out by inserting in safe
area an Intrinsic Safety barrier with galvanic isolation.
Electrical safety data for intrinsically safe circuit:
Leakage detector Ui: 30V; Ii: 120mA; Pi: 1.3W
Ci: 0.3nF; Li: ~ 0mH
Cable Cc: 200pF/m; Lc: 1µH/m; Lc/Rc= 30µH/Ω

3.6 Electrical connection (standard version)

To set up the electrical connection of the electric pump, do the following:
1. Check which type of electrical connection is required on the identification plate (direct starting or Y/D).
2. Firstly, connect the earth wire to the relative terminal in the electrical panel, according to the connection diagram illustrated.
3. Connect the power wires to the relative terminals in the electrical panel, according to the followings connection diagrams (please refer to the
specific documentation supplied with the unit for electrical connections of non-standard sensors and protective devices).
4. Connect the wires of the control devices to the terminals on the relative panel.
WIRING DIAGRAMS PAGE 78

4. COMMISSIONING

4.1 General safety precautions

• All operations must be carried out by skilled technical staff.
• The pump must always be used with the safety devices installed and in good working order.
• Keep objects and people at a safe distance from the machines installed and do not allow people or animals to come into contact with the liquid
in which they are immersed.
• Before carrying out any operation, make sure that the pump and electrical panel are disconnected from the electrical mains and cannot be
accidentally powered up.
• Before connecting the pump to the power supply panel, check that the impeller can turn freely.
• Check the level and the condition of the oil in oil chamber.
• Check that the impeller turns in the correct direction using the procedure described in point 2.4 "Checking the impeller rotation direction".

4.2 Starting the electric pump

The pumps must not be started if the atmosphere in the tank is potentially explosive.
Once installation is complete, the system should be tested to ensure that it is fully operational.
The pump must always be used with the safety devices installed and in good working order; make sure that all protective equipment has been
connected correctly.
The pump must not run dry; check that the liquid level is above the motor.
Check that the required gate valves (where fitted) fuction are open.
Switch on the power supply and let the pump run briefly and:
• check that the input current is within the limit stated on the nameplate;
• check whether the monitoring units are operating satisfactorily (no alarms or warnings);
• check the setting of the level control system (minimum and maximum levels).
First installation manual – Translation of original instructions
EN
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