Intellichlor Sensor Hack - 3 Wire Flow Switch

[poolkid]

My (just cleaned) IC-40 cell is reading ~2000 ppm even though my LaMotte (same as Taylor K-1766) test kit is showing ~3200ppm. After reading through the sensor hack threads, I thought clipping the white and green wires should (temporarily) confirm that the thermister in the flow switch had failed. After stripping back the insulation I discovered that there's only 3 wires in the flow switch cable. I clipped only the white (sensor) wire and now the screen logic is showing 0 ppm of salt and the cell "low salt" light is red.

What's the wiring hack for a new temp sensor if I've only got 3 wire, ie: no green wire?

 

[mknauss]

One of the wires is now common. I think it is the black one -- but searching for that information.

 

[Jimrahbe]

kid,

Marty is correct, the black wire is the common wire for one side of the flow switch and one side of the thermistor.

After you cut the white wire, did you re-boot the system? The cell only reads the salt level at start up and then every 12 hours.

Thanks,

Jim R.

 

[ajw22]

Or see page 5 in https://www.pentair.com/content/dam...low-switch-replacement-kit-manual-english.pdf

 

[poolkid]

kid,

Marty is correct, the black wire is the common wire for one side of the flow switch and one side of the thermistor.

After you cut the white wire, did you re-boot the system? The cell only reads the salt level at start up and then every 12 hours.

Thanks,

Jim R.

Yes, I did reboot the system by virtue of turning off the breaker prior to cutting the white wire. I never play with wiring of any voltage, even data only wires, with the power on.

So I'll assume that I've got to splice one of the thermister wires into the black wire, and connect the other to the white wire. I'm wondering why cutting the white wire didn't revert the cell to the default 72° temp setting?


Thanks Jim, Marty, and AJ for the help!

Steve

 

[ajw22]

• Black to black
• Red to red
• White to white
• Cap off green which does not get connected to a wire.

 

[Jimrahbe]

Kid,

I am not sure what is going on..

I know the flow switch can cause the cell to report zero salt, but when then happens, the cell will often works fine, it is just a reporting problem. The cell still knows what the salt level is.

That does not seem to be the case for you. I would have assumed that when you removed the flow switch thermistor from the circuit, the cell would have started using its internal resister and the salt level at the cell would have been ok.

I guess you could add a 10K resistor between the black and white wires and see what happens.

When the cell fired back up did you get a green flow light and the "Railroad Crossing" flashing lights?

Thanks,

Jim R.

 

[poolkid]

• Black to black
• Red to red
• White to white
• Cap off green which does not get connected to a wire.

Shopping for a replacement flow switch, I found this diagram. I'll try a thermister (I might have a used one somewhere) or a resistor before springing for the whole switch.

Steve

 

[poolkid]

Kid,

I am not sure what is going on..

I know the flow switch can cause the cell to report zero salt, but when then happens, the cell will often works fine, it is just a reporting problem. The cell still knows what the salt level is.

That does not seem to be the case for you. I would have assumed that when you removed the flow switch thermistor from the circuit, the cell would have started using its internal resister and the salt level at the cell would have been ok.

I guess you could add a 10K resistor between the black and white wires and see what happens.

When the cell fired back up did you get a green flow light and the "Railroad Crossing" flashing lights?

Thanks,

Jim R.

Yes... I've got flow and lights flash as normal on initial power up while it tries to sense salt level - even with the white wire clipped.

Steve

 

[ajw22]

Shopping for a replacement flow switch, I found this diagram. I'll try a thermister (I might have a used one somewhere) or a resistor before springing for the whole switch.

Steve

That is from a 3rd party flow switch and does not agree with the Pentair instructions.

Green wire should not be connected to black.

From experiences here 3rd party parts do not always work properly. I recommend Pentair parts be used inspite of the cost. If you have a non-Pentair flow switch it may be your problem.

 

[poolkid]

That is from a 3rd party flow switch and does not agree with the Pentair instructions.

Green wire should not be connected to black.

From experiences here 3rd party parts do not always work properly. I recommend Pentair parts be used ins pit of the cost. If you have a non-Pentair flow switch it may be your problem.

The cell was mfg in May of 2020 and the flow switch is the OE part.

I sweet talked Pentair warranty into sending me a free replacement flow switch.

I appreciate your input.


Steve

 

[GK's pool]

The cell was mfg in May of 2020 and the flow switch is the OE part.

I sweet talked Pentair warranty into sending me a free replacement flow switch.

I appreciate your input.


Steve

Hello,
I was wondering if the new flow switch solved your problem. I have the exact same issue and have had no resolve in the low salt light after cutting the white wire. Actually salinity is 3400.

Thanks,
Gary

 

[poolkid]

Hello,
I was wondering if the new flow switch solved your problem. I have the exact same issue and have had no resolve in the low salt light after cutting the white wire. Actually salinity is 3400.

Thanks,
Gary

Hi Gary,

Unfortunately the flow switch didn't solve the problem. I ended up having to replace the entire cell. As a retired pool contractor and Pentair dealer I was able to talk the warranty rep into sending one to me under warranty even though it was 2 1/2 years old.