Question about Tsurumi Pump s Submersible Water Pump 3810 GPH 12 HP 2in Model LB48

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May tsurumi submersible pump is i need to oil on the plug of the of the pump? Is it ok if increase the discharge diameter? What will be effect of it? Hope u could enligthen me on this problem tnx. From arthur

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This is a single phase induction motor. You mentioned it is overheating. You did not mention whether or not you had easily turned the pump by hand. Pumps overheat for several reasons but these are the top 4:
1. The head pressure is too high as in the pump is being used to pump water higher than the head level of the pump. (Lift distance to high)
2. Low utility or generator voltage. Lower than the pump rated input power requirements.
3. Bearing Friction or motor / bearing mis-alignment ( 3. Pump is sitting in debris while pumping and the pump inlet is being blocked by debris. Also... if it sat in clay and the clay dried inside the pump it can restrict water passages to the point that the pump just can not pump enough water to stay cool.

Does it overheat when pumping at 15 feet or less? I note that this is actually a 1/2 Hp pump. The max LIFT distance for most 1/2 Hp Pumps is 23 feet or less using a 1 1/2 in discharge. The lift will be even less with a 2 inch discharge outlet. As for oiling the pump... Most submersibles always have oil above the impeller and it usually does NOT leak out unless the seal between the impeller and the motor stator / aramture has failed letting water into the winding. That plug you mentioned is for checking to see if water is in the winding area. If you pull the plug and get water the seal is bad. Hopefully you can save the winding.

You asked what the effect would be if you went to a larger discharge diameter. This will give you more volume but less head / lift distance.

Thanks for choosing FixYa.

Posted on Apr 06, 2011

  • Maxime Desmeules Apr 16, 2011

    Great answer!!!

    Arthur how long have you been using this pump? if its less then a month the piping might be an issue, more then that mean its not the issue,

    Maybe its just block with debris, tell us more and we will help you more,

    Dont put oil,there is no need for it everywhere else then,
    There is an hex nut on the side of it and this is the oil chamber that need aprox 170 ml of oil (anykind) wich is use to lubricate the mecanical seal,to help her pumping forever,it is also use to check the condition of the oil,
    If there is water with the oil you need to do maintenace on it, i suggest you to check this only once a year tho or when the impeller(wheel) will need to be replace due to work,

    Have a great day,


  • Phillip Allegretti
    Phillip Allegretti Jun 01, 2014

    My Tsurumi pump still pumps but it is making a loud noise. Is this something I can fix or do I need to buy a new pump ?



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