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NT 1004-C00 03 18 SLC12 i - SLC18 i - SLC12 i HT - SLC18 i HT e
14. TROUBLESHOOTING (continued)
ABNORMAL HEATING OF BEARINGS
4
This heating can be caused by :
4-1
- excessive tension in the transmission (belt or chain) on the pump shaft.
4-2
- excessive pulling on the pump flanges by the piping (in this case, it must have been necessary to force
the piping into position to connect it to the pump).
4-3
- poor alignment of the pump - due for example to 4-2 (the pump is partially or totally uncoupled, the
pump shaft and drive shaft are not aligned with each other).
4-4
- inadequate anchoring of the pump unit leading to deformation of the chassis (make sure that the chas-
sis is clear of the ground except for the 3 anchoring points).
ABNORMAL NOISES
These noises can be caused by hydraulic and mechanical sources. They can be distinguished by the fact
that only the former disappear (or at least lessen) when air is allowed into the inlet pipe.
5
HYDRAULIC NOISES
These noises can come from insufficient product being supplied to the pump, or :
5-1
- the rotation speed is too high for the installation conditions (increase of viscosity due to a change of
product or a reduction of temperature, etc.).
5-2
- that the suction head is too high or has become too high due to excessive head losses following clog-
ging of the piping or filter, a change of viscosity of the liquid, etc.,
5-3
- an increase of the vapour pressure with a rise of temperature.
6
MECHANICAL NOISES
These can stem from :
6-1
- abnormal stress on the pump : the transmission is pulling on the shaft, pulling on the flanges by the
piping.
6-2
- a broken part or foreign body has entered the pump.
EXCESS POWER CONSUMPTION
7
The most spectacular event occurs when the power to an electric motor is shut off.
7-1
If this incident occurs when closing the discharge line, the cause may be the motor protection is adjusted
too low or wrong circuit breaker have been fitted.
7-2
If the incident occurs during operation, the cause could be :
a. an inadequate motor (in this case, the discharge pressure complies with what was expected).
b. head losses higher than expected - following higher viscosity or specific gravity than planned initially
(in this case, the discharge pressure is higher than that planned. The pressure can be reduced by
loosening the relief valve adjustment screw - the flow is decreased).
c. excessive speed of rotation.
d. a fault of the equipment (faulty alignment, deformation of the chassis, stress exerted by the piping on
the flanges, seizing, etc.).
Excessive consumption of electricity can also be due to a poor motor connection (e.g. a 3 phase motor
operating on 2 phases).
