Float switch wiring to AC Jr.

[Stu]

Last night I came home to a nearly empty sump and the shower pan liner in the bottom of my stand with about 2 inches of standing water. I wasn't really sure how it had happened at first, but soon realized that it was due to the skimmer overflowing.

 

Something made my skimmer go nuts and overflow down the connected tube, into my little waste collector outside the sump. Once this collector was full, it just overflowed out of that into the bottom of the stand (and thankfully stayed there because of the shower pan liner).

 

I have an Aquacontroller Jr. that controls my tank. I would like to wire the float switch to the ACJr. so that it will shut down the skimmer if it overflows again. The AC3, Apex, etc. have a breakout box for float switches, but the ACJr. doesn't accommodate a breakout box. The ACJr. manual says you can wire one float switch to the serial connector point. Has anyone done this or know how to do this?

 

Pages 21-23 of the manual say you CAN do this, but don't show HOW to do it:

 

http://www.neptunesys.com/images/downloads/AquaControllerJr_3_2%2BSerial_web.pdf

[ctenophore]

The manual should have the pinout diagram for the serial port. You basically just need to get the minidin-8 plug (radio shack might have one, I got some online) and solder the float switch wires (red=input, black=common) to the correct minidin head wires. Unfortunately it is somewhat tricky. I have not done it with an ACJr, not sure if it has a minidin port (round w/8 pins) or a wide, flat serial port. In either case, the instructions are the same- one float switch wire to the "input" pin, the other to the common.

[Stu]

It looks like it's a round plug. The diagram gives this description:

 

Pin Number----Description

1-------------External Switch Output

2-------------External Switch Input

3-------------Serial Transmit Data

4-------------Ground

5-------------Serial Receive Data

6-------------Ground

7-------------Reserved

8-------------Ground

 

I am assuming I would solder the red wire to the "External Switch Input" pin (Pin Number 2). Which should the black common wire be soldered to?

Edited March 8, 2010 by Stu

[ctenophore]

I think any of the grounds, 4, 6, or 8 should work.

[Stu]

Someone on RC said he wired his to Pins 1 and 2. Does that sound like it would work? Still wire the black to a ground?

[ctenophore]

Pin 1 would be voltage coming from the AC3. Since nothing is programmed to allow the AC3 to create voltage on that line, yes it would probably work. But I don't think it is correct. Maybe one of the EEs here can chime in.

[hypertech]

If you can find an old PS2 mouse/keyboard, or extension cable, they work. Use a small pliers to bust out the rectangle key fitting in them and then it fits in the Jr. I have mine wired to a switch to kill my skimmer when I want to do a water change.