Multi Tank ATO: Adding Float Switches to Jebao DP-4

tkeracer619

New member
I am not normally one who cheaps out on dosing pumps. I have about $10k retail value of masterflex hardware in my setup but I ran into a situation that required I have 6 ATO setups. My typical setup is an AutoTopOff.com float switch and a masterflex peristaltic but that was going to be cost prohibitive for this particular project. I decided to modify a pair of Jebao DP-4 dosing pumps to accept float switches. This thread should give you the info you need to do this yourself. I am linking the items I bought but have no monetary or incentives from the sellers to do so. They simply have the specs we need and are cheep.

I'm sure there are other ways to do this but I feel like this is a cheap and reliable way to create a bunch of Auto Top Off systems for those folks who need several setups or for someone who needs an ATO and has a spare channel on their dosing pump, Modifying only one channel would allow you to use it as an ATO.

Hope this is helpful to someone :D. Enjoy!

Supplies needed...
Jebao DP-4 Dosing Pump (others hobbby pumps will probably work in a similar manner)
Float Switches
Connectors - Plugs and Sockets
Relay Board
Marine Grade Heat Shrink Tubing
Various size heat shrink tubing.
6-32 Button Head Screws 2" Long and an extra pack of nuts.
Wire ~22ga
Screwdrivers
Wire Strippers
Soldering Iron - Use a good one

In case you aren't sure, this is the one we are talking about. It's a 4 head pump. I purchased mine via international snail mail for about $55ea. Make sure it functions before taking it apart!

First step is to open up the case. The silver tabs on the front slide up towards you if you are looking at the screen, this gives you access to the clips. Prod in here with a slotted screwdriver. Take care not to drop the pump assembly when taking the case apart. It is best to do this with the screen facing the ground and removing the back of the case from the front.

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Once open with the screen facing a bench, this is what we have. Go ahead and unplug all of the cables and remove the pump assembly, set it aside. Remove the 4 Phillips screws that hold the logic board, we will mod it in the next step (pictured at the top)
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We need to tap into the 12v power supply to drive our relay board. On the back of the logic board solder two wires to the shown solder joints. Take care not to overheat the board. Use 12" wires here, they will be cut to length at a later time. Note polarity and be sure you can identify which is positive and negative once the board is in place.
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With the logic board out remove the backplate. Use a O size bit (or whatever you have that fits the sockets snugly) to drill the back plate as shown for the float switch input sockets.
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Cut the plugs off of the motors. Cut the black wire as short as you can but leave about 2.5" of the red wire intact.
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Strip back a small amount of insulation, slip some heat shrink tubing over the wire, and solder this wire to the shortest tab on the socket. Note the orientation of the socket in the image...
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Solder an additional wire (black) to the middle (medium) pin on the connector. Apply heat shrink tubing to this pin as well.
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Re-install the back plate, the logic board, and install the female connector. Plug the red wire back into the logic board as shown. Go ahead and mark the outside of the back plate with the corresponding number on the logic board so you don't get confused later on (LED1,2,3,or 4).

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Repeat this step for the other 3 Female connectors as shown.
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Multi Tank ATO: Adding Float Switches to Jebao DP-4 (cont)

Multi Tank ATO: Adding Float Switches to Jebao DP-4 (cont)

Drill out 3 of the mounting holes in the relay board. Don't drill the one with the purple x as it is too close to a trace. We'll only be using 3 mounting holes. If you can find a 2" long #4 button head you probably won't need to drill.

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Drill and mount one screw at a time using the board as a guide. Our goal here is to get the board over the screen board and closer to the back of the unit without covering the plugs you did in the previous step. Secure each screw with a nut to fasten it to the case. Use a nut as a standoff and one one to secure the board. I use a small piece of vinyl tubing (same I use to plumb the pump) as insulators on both sides of the board.

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Take the other wire you connected to the female connectors (black) and connect it to the corresponding trigger input on the relay board. **At this point make sure the jumpers on the relay board are set to LOW trigger.** If you use a different relay board know that due to the way this pump is wired the board must be able to trigger on a low input.
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Please take note of the step, it is a little confusing!
-Re-install the pump module
-Connect the black wires off each motor (4), a 12" long red wire, and the to the positive wire (RED) you attached to the logic board together.
-Connect 4 wires, a 12" long black wire, and the negative wire (black) you attached to the logic board together.
-Connect the red wires off each motor (4) to the NO connection on the relay board that corresponds to the input number. Ex... float 1 - led 1- trigger 1 - pump 1
-Connect the 4 12" long black wires to the COM connection on the relay board to the 4 relays that are now in use.

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Assemble the float valve setup using two floats soldered in series. Use the marine heat shrink tubing here. Use a two wire conductor as an extension. Solder the male connectors and secure all of the wiring. You want to ensure none of this stuff will move or be damaged easily.
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Re-Assemble and test the modification by operating the pumps and float switches manually.
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Install, calibrate, and program the pumps to provide enough water to use the bottom float switch. My program has the pump coming on 10x a day, every day, 100ml each time, at 2am, 4am, 6am, 8am, 10am, 12pm, 2pm, 4pm, 6pm, 8pm, 10pm. There are plenty of videos on how to program so I won't go into that. Bottom line is my demand is 900ml/day so I set the dosing pump to dose 1000ml/day.

I'm using two of these setups on a BTA propagation system.
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If you have any questions or comments please don't hesitate :)
 
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