FE VKN Serie Manual De Instrucciones página 7

3. Construction
1) Coolant pump is a centrifugal pump. The amount of flow can be adjusted as desired by
opening and closing the outlet valve. The motor is free from overload even when the valve is
closed. However, if the valve is left closed for many hours, the fluid in the pump increases in
temperature. In such a case, allow a little flow (more than 100 cc/min) or stop the motor if it is
not used.
When the fluid temperature is too high, it reduces the life of the motor or damages the shaft
seal (VKN series).
2) When the fluid level is too low, air may be sucked into VKP, VKR and VKS type pumps, making
pumping impossible. Therefore, the recommend marginal and minimum fluid levels are
marked on the outline drawing on the left and on all immersion type pumps.
(Pump VKP113A, 115A, and VKS are an exception to the above statements, because its
delivery inlet faces downward, while the inlets of other pumps face upwards.)
★ Marginal fluid level: The level at which the quantity of fluid is almost equal to the rated value,
assuming that no air is being sucked into the delivery inlet.
★ Minimum fluid level: The level at which the quantity of fluid is about 1/2 the rated value,
assuming that air is being sucked into the delivery inlet, but not in a quantity large enough
to affect pump operations.
★ Maximum fluid level: The level 10 mm to 20 mm below the oil thrower, which is attached to
the shaft between the pump and motor to prevent oil from flowing into the motor.
The above fluid levels were obtained with cutting oil that had a viscosity of about 32R".
Such levels vary according to the viscosity of the fluid used. They have to be raised when fluid
viscosity is higher than the viscosity of water, or 32R".
A fluid with a viscosity lower than the maximum value should be used, since a highly viscous
fluid requires a large force to circulate it.
And, the use of large forces to circulate fluids can cause motors to overheat.
In winter, special attention should be given to fluid viscosity. For safety reasons, the oil in the oil
tank should be at as high a level as possible.
In case of power failure during operation, be sure to turn OFF the power switch.
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