Question for all you boaters out there

[Jonathan Clark]

Hey Guys,

I just purchased some Bilge Pump Cartridge Motors (Johnson Pump 28552) that I'm going to be using as thrusters on a custom built R.O.V..  I have searched high and low trying to any information related to the typical current draw on these things and haven't been able to find any.  I was thinking there might be a small chance some of you guys have tinkered with replacing these cartridges or for some other reason may have some idea what I should expect.  I'll be able to find out for sure once they arrive but I'm trying to also order some motor controllers right away and want to make sure I get ones strong enough to power these motor. If anyone has any advice or input, let's hear it!

[DE 'Tad' Heckaman III]

Hmm... current draw? As in amps? :) Or are you looking for more real-world figures?

Output 0' = 720 GPH, Output 3' = 630 GPH, Output 5' =500 GPH; Hose Size = 3/4", Voltage, Design, = 13.6VDC; Amp Draw = 1.4 Amps; and Fuse Size 2.0. 

On Tue, Jun 19, 2012 at 7:46 AM, Jonathan Clark <jdc...@gmail.com> wrote:

Hey Guys,

I just purchased some Bilge Pump Cartridge Motors (Johnson Pump 28552) that I'm going to be using as thrusters on a custom built R.O.V..  I have searched high and low trying to any information related to the typical current draw on these things and haven't been able to find any.  I was thinking there might be a small chance some of you guys have tinkered with replacing these cartridges or for some other reason may have some idea what I should expect.  I'll be able to find out for sure once they arrive but I'm trying to also order some motor controllers right away and want to make sure I get ones strong enough to power these motor. If anyone has any advice or input, let's hear it!

--
Tad Heckaman

[Ben Hibben]

The page lists 1.4 Amps as its normal draw and a 2 amp fuse so if you go with something around that level you ought to be safe as far as I can tell.  I'm not really an expert on motors though.

Blenster

On Tue, Jun 19, 2012 at 7:46 AM, Jonathan Clark <jdc...@gmail.com> wrote:

[Jonathan Clark]

Well... I tried but I can't come up with any believable excuse for why in the world I didn't see the current draw rating ON THE PAGE THAT I LINKED TO ABOUT NOT BEING ABLE TO FIND THE CURRENT DRAW RATING!  (should have slept a little more last night)

However....

I'm glad that I didn't because I kept searching and found where another person was using these motors for the exact same purpose I am, and he had done a TON of experiments to test the current draw using multiple props and at various water pressure levels.  Although he was using a slightly larger motor (750gph), he was reading somewhere between 4.5 - 7 amps on motors that were spec'd to draw around 2A.  So it looks like adding the props to the motors does require a bit of increased current.  I'm going to shoot for controllers that can handle around 12A continuous as I plan on going up to the 1250gph motors very soon.  

Thanks for pointing out what was right in front of my face! :)

[Joe Pugh]

Awesome, Jon is going to catch motor controls on fire under water!

[Brad Luyster]