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santosh zingurde
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Join Date: Nov 2011
Posts: 28

Pump Operation

07/28/2012 8:03 AM

dear gurus,

our monoblock does not burn when runs on no load, but submercible pump when runs dry burn out, didnt understand reason?

regards

santosh
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lyn
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#1

Re: pump operation

07/28/2012 10:14 AM

Don't run a submersible pump unless it is covered by water, or fluid. They are not designed to be air cooled.

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Kilowatt0
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#2

Re: pump operation

07/28/2012 10:19 AM

I have no idea what you are calling a "monoblock". Please give a better definition.

As for the submersible pump:

1. A submersible pump will use the fluid being pumped as a cooling medium, to take heat away that the motor is producing.

2. When you run dry, the pump will cavitate. Basically, since it can no longer pump, all of the heat due to friction will be imparted to the fluid remaining in the volute.

3. The above 2 reasons (along with a waste of energy), is why you should have a "low level cutoff" (usually a float switch) in the pump circuit.

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JRaef
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#3

Re: Pump Operation

07/28/2012 12:28 PM

Monoblock fillling machine?

Machines generally don't care if they are loaded or not, but pumps do. A submersible pump should NEVER be run dry. If you need to run the filler/capper in order to set it up or test the timing etc., disable the filling pump first.

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pnaban
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#4

Re: Pump Operation

07/28/2012 11:08 PM

When a centrifugal pump runs without water, shaft,seal/gland packing etc will be overheated but motor may not burn out.Give details (type/model/brand etc)of your mono-block pump/deep-well submersible pump/drainage pumps. In deep well submersible pumps bearings and motor are water cooled,if no water they will get overheated. In sewage/drainage submersible pumps motor may be oil cooled so when you run without water what did you observe?.

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