Fuel Pump Blowing Fuses

Discussion in 'The Projects Forum' started by Robinloftus, Feb 29, 2016.

  1. Robinloftus

    Thread Starter New Member

    Feb 29, 2016
    2
    0
    I have made a simple fuel pump trolley. It uses two 12v 42amphr lead sealed batteries wired in series to give 26V (measured). I am powering a small 24VDC diesel fuel pump. The device is for emptying fuel and lube tanks on our engine test rigs. The fuel pump is rated at 7amps current draw with a max current of 10A. When pumping cold lube I think the current inrush is blowing the fuse (10A switch fise).

    Any ideas how to prevent this? Its not the end of the world if the pump is slowed down slightly. I was looking at current limiting thermistors but my electrical experience is a bit below the task....
     
  2. Dodgydave

    Distinguished Member

    Jun 22, 2012
    4,986
    745
    i would put an ammeter on the pump to see what currents are being drawn, then select a fuse slightly higher.
     
  3. Robinloftus

    Thread Starter New Member

    Feb 29, 2016
    2
    0
    I am just concerned about the pump as it came with the 10A fuse as standard. You could be right however, it may just be going slightly over....
     
  4. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,545
    2,370
    If you say pumping cold, maybe the viscosity at that temperature presents too heavy a load on the motor, especially if a gear pump, which it could be.
    Check the current once running and if about normal, you could place a contact on the start PB that by passes the fuse momentarily at start up just to get past the stall current stage. Do not abuse it by holding it more than a couple of seconds though.
    Max.
     
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