Dna-Ex - Dnb-Ex; Lower Mechanical Seals Replacing; Tools; Troubleshooting - dreno Compatta Pro Serie Manual De Uso

A) Unscrew the 3 socket head screws that connect the pump body with the motor casing.
B) Now, extract the pump body from the motor casing.
C) Using a wrench, unscrew the self-locking nut that fastens the impeller.
D) The impeller should now easily remove from the motor shaft.
Before itting a new impeller, pay attention that the end of the shaft is clean and has no imperfections.
12.5 DNA-EX - DNB 80-EX
A) Unscrew the four screws that connect the motor casing to the body pump.
B) Unscrew the four screws that connect body pump to closing plate and remove the closing plate.
C) Keeping the impeller blocked, unscrew the hexagonal head screw or the self locking nut, which connect it
to the motor shaft.
D) Unscrewing this screw or nut, you can easily remove the impeller. Before mounting a new impeller, pay

13. Lower mechanical seals replacing

The following operations should only be carried out by qualified DRENO POMPE engineers.
To replace the mechanical seal, carry out these operations in sequence.
A) Before replacing a mechanical seal, uncouple the impeller as indicated in paragraph 12.
B) Using two cutting screwdrivers, remove the old seal, irst lever the rotating part and then the ixed ring,
paying attention to position the pump so that oil does not seep from the sump. (GM-GT 50/2/110 C.149-
150 and AM-AT 50/2/110 C.225-226 solely)
C) Before itting a new seal, ensure the housings are clean, free from burrs or grooves that could damage the
seal or in any case compromise the sealing to the shaft.
WARNING: It is advisable to avoid jamming, which may prejudice breakage of the ixed ring, after inserting
the ixed ring insert the rotating part of the seal.
D) For GM-GT 50/2/110 C.149-150 insert and ix the impeller ixing the screw UNI 5931 M5x50 A2 using a
clamping torque of 9.5 Nm.
For AM-AT 50/2/110 C.225-226, COMPATTA PRO, ALPHA V PRO, BIC PRO, DNA -EX, DNB -EX insert the
impeller in the shaft paying attention to the key direction, tighten the self-locking nut by a torque of 9.5 Nm.

14. Tools

The tools used exclusively by qualiied DRENO POMPE engineers are:
• Allen keys: 4 - 5 mm
• Phillips screwdriver
• 2 cutting screwdrivers
• Hexagonal wrench: 8-17 mm
D) For GM-GT 50/2/110 C.149-150 insert and ix the impeller ixing the screw UNI 5931 M5x50 A2 using a
clamping torque of 9.5 Nm.
For AM-AT 50/2/110 C.225-226, COMPATTA PRO, ALPHA V PRO, BIC PRO, insert the impeller in the shaft
paying attention to the key direction, tighten the self-locking nut by a torque of 9.5 Nm.

15. Troubleshooting

If the electropump doesn't start, one of the following cases could be happened :
• There is no power supply (Check the fuses to see if they are burnt or if a circuit
protection relay has tripped.);
• The selector is on OFF (select ON.);
• A phase is missing (Check the line connections);
• The impeller is blocked;
• The mechanical seal or ball bearing have seized.
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