Pentair Intellichlor ICXX SWG - Further Reading

IntelliChlor Operation

2023 Pentair Sanitizer Catalog

2023 Pentair Sanitizer Parts Catalog

Do Not use Dry Acid

Pentair specifically says on page 9 in the IntelliChlor SWG Manual[1] - CAUTION: The use of dry acid (sodium bisulfate) to adjust pool pH is discouraged especially in arid regions where pool water is subject to excessive evaporation and is not commonly diluted with fresh water. Dry acid can cause a buildup of by-products that can damage your chlorinator cell.

How to Determine the IntelliChlor Cell Usage

The IntelliChlor SCG has a built-in cell “usage hours” meter that displays how many hours IntelliChlor has been generating. The IntelliChlor SCG is designed to generate chlorine for approximately 10,000 hours before replacement is needed.

To access the system status mode:

  1. Press and hold the MORE button for three (3) seconds until the lights scroll across the unit.
  2. One (1) of the five (5) Sanitizer Output LED indicators (20%, 40%, 60%, 80% and 100%) will be lit,indicating the hours of usage.

The Output LEDs are as follows:

  • 2000 hours (20% LED on)
  • 4000 hours (40% LED on)
  • 6000 hours (60% LED on)
  • 8000 hours (80% LED on)
  • 10,000 hours (100% LED on)
Pentair IntelliChlor Controls.png

What Does the Flow/Temperature Switch do on the IntelliChlor?

The flow switch also contains a thermistor that senses water temperature. The water temperature is used for the salinity calculation. If the thermistor is failing the salinity will be incorrect.

Flow switch has 4 wires on cells manufactured before September 2018:

  • Red/black - flow switch
  • Green/white - temperature sensor

Flow switch has 3 wires on cells manufactured after September 2018:

  • Red - flow switch
  • White - temperature sensor
  • Black - common

The IntelliChlor uses the Harwil Q-12DST-C2 flow switch.[2] It has an integrated 10k thermistor.[3]

With no temperature input, the cell defaults to a temperature of 77 Fahrenheit. The sensors are prone to failure. When the sensor fails and it's obvious to the software that the sensor has failed, it defaults to a standard temperature of 77 f.

A suspected bad flow switch can be confirmed by cutting the black and red wires and connecting them together coming out of the cell. If the cell operates with the wires connected this confirms the flow switch was bad. Do this only for temporary diagnostic purposes.

What Causes the High Salt Light on the IntelliChlor?

High salt error occurs around 4500ppm. The cell will continue generating chlorine with a high salt warning.

What Does the IntelliChlor Low Salt Light Mean?

Always check salt level independent of the cell before adding salt. A failure of the temperature sensor will give incorrect salt warnings.

The red/green flashing light means the unit is trying to run the salt test, but until you have flow it will not pass.

The LOW SALT LED being red has two possible meanings:

  1. Low salt. The water salt level is below 2800 ppm. The IntelliChlor SWG will be producing chlorine at reduced efficiency and is highly recommended to add salt.
  2. Very low salt. The water salt level has fallen below 2600ppm. The IntelliChlor SWG will not produce chlorine until salt is added. The IntelliChlor SCG is OFF as shown by the green CELL LED being OFF..

What Does the IntelliChlor Do in Cold Temperature?

The cell will stop generating chlorine when water temperate is below 52° F, ±3° F (11° C, ±1.67° C) degrees.

If the cell light says cold when the water is warm, the temperature sensor inside the flow switch assembly is likely bad.

If you are going to replace the flow switch anyway, you can just cut the green and white wires going from the flow switch assembly and the cell itself. When you cut the wires, the cell will use a fixed resistor inside the cell. Reboot the system and if the cold-water light is off, you will know for sure that the flow switch needs to be replaced.[4]

How Do You Display IntelliChlor Cell Water Temperature?

Version 3.1 on adds the ability to determine system temperature. Pressing the “More” button after the display shows 1,000s of hours of usage, will show temperature as follows:[5]

https://www.youtube.com/watch?v=qlL5bZzA1So

Lights Temperature
No LEDs Below 30F
40% 36 to 45F
40% and 60% 46 to 55F
60% 56 to 65F
60% and 80% 66 to 75F
80% 76 to 85F
80 and 100% 86 to 95F
100% 96 to 99F
100% blinking over 99F
All LEDs blinking Sensor bad

Press and hold the More button until the lights scroll and note which % light lights up. Then, immediately press the More button again and see which % lights light up.

How Should the IntelliChlor Be Cleaned?

You should only soak your cell in a MA solution if you cannot clean scale by other less damaging methods.

See other methods of cleaning the cell in SWG How It Works.

Pentair has two cleaning tools:

  • Pentair 520670 IntelliChlor Acid Washing Kit​ which is a cap to hold cleaning solution in the cell
  • INTELLICHLOR AND iCHLOR ELECTROLYTIC CELL ACID CLEANING KIT (P/N 523103) which contains an O ring and a wash stand.

Verifying if the IntelliChlor Cell is Generating

If the CELL light is green then the cell should be generating chlorine.

A simple test is set the cell to 50% and watch the cell for a few minutes. At 50% the Cell light should be on for 2.5 minutes and then off for 2.5 minutes, etc. If the cell light passes this test, then the cell is making chlorine. If the CELL light never comes on during the test, then the cell is not making chlorine.

Some people look for champagne like bubbles coming out of their returns which is from the hydrogen gas byproduct of the generation. However that is not conclusive as the bubbles may come and go with varying pump speed.

To electrically confirm the cell is generating you can use a clamp ammeter to measure the DC current at the red or black wire on the surge board. It should be about 6 to 8 amps DC.


IntelliChlor Surge Board Marked.png

Where is the Manufacturing Date on the Intellichlor?

The manufacturing date should be on the label on the bottom of the cell.

IntelliChlor Cell Dimensions and Placement

The IC15/20/40/60 needs 17 inches to be cut into a PVC pipe. The cell is just under 16" from the end of one union to the end of the other union.

Pentair Intellichlor Specifications.jpg
Pentair IntelliChlor Union Dimensions.jpg

The cell should be placed where it chlorinates both the pool and spa if you have one. If connected to Pentair automation you can set separate output % for the pool and spa.

For best flow sensing, provide at least 12"-18" of straight pipe in front of the cell inlet.

Pentair recommends installing the IntelliChlor SCG cell vertically for best performance. The cell works fine being horizontal.

If the cell is installed vertical the water must flow up as shown in the Installation Manual. Do not install the cell on the downflow leg.

The IntelliChlor SCG should be at least three (3) feet away from the heater outlet.

How to Replace the IntelliChlor Flow/Temperature Switch Assembly

Pentair IntelliChlor Flow Switch 3 wire wiring.png

Pentair has the IntelliChlor Flow-Temperature Switch Replacement Kit (P/N 520736) / iChlor Flow-Temperature Switch Replacement Kit (P/N 523100). It contains:

  • Flow-Temperature Switch Assembly
  • Watertight Pair-at-a-time Connectors (Qty. 2)

Follow the enclosed directions to remove the existing flow/temperature switch.

IntelliChlor cells manufactured before September 2018 use 4 wires (red/black & green/white) for switch connections. Cells manufactured after September 2018 use 3 wires (red/black/white) for switch connections.

You may get either the old four wire flow switch or the new 3 wire flow switch as a replacement. The 3 wire flow switch can be used on older 4 wire cells. The 4 wire flow switch cannot be used on the new cells manufactured after September 2018.

Pentair's 2008 directions for replacing the 4 wire assembly may be more understandable then the 2019 directions for replacing the new 3 wire assembly that includes the iChlor.

Replacing Bad Temperature Sensor in the Flow Switch with a Separate Sensor

Pentair has the temperature sensor integrated with the Flow Switch. If the temperature sensor fails Pentair expects the entire Flow Switch assembly to be replaced. The temperature sensor in the Flow Switch is a standard 10K thermistor temperature sensor which can be used in place of the one in the flow switch.

Install the thermistor in the plumbing near the cell using a water temperature probe, like the one that comes with an EasyTouch. Drill a hole in the pipe, stick in the probe, and use a hose clamp to hold it in place.[6]

Temp probe hack.jpg

Then cut the green and white wires in the flow switch. Attach the two wires from the thermistor to the green and white wires going into the cell using Scotchlok UR2 connectors so you don't have to strip the wires. Just crush the button and the wires are connected. The two green and white wires coming from the switch will be left disconnected.

Newer Cells (after 2018)have a 3 wire system. The black wire is common. Just cut the white wire, attach one wire from the thermistor to the white wire, and one to the common black wire.

3 wire external thermistor.jpg

Now the cell sees the water temp from the new probe and not the thermistor in the flow switch.

How Does the IntelliChlor Calculate Salinity?

The salinity is calculated based on the conductivity of the water and the water temperature.

The conductivity sensor is a separate device in the cell which can be seen if you look in the cell.[7]

The IntelliChlor manual states that measurements will vary between measuring devices (salt test strips, electronic testers, andtitration). The salt sensor reading is within +/- 500 ppm accuracy.[8]

What is the Recommended IntelliChlor Salt Level?

  • 3600 ppm of salt is recommended for optimum water condition.[9]
  • Low salt concentration below 2600 ppm will cause the unit to turn off
  • High salt concentration above 4500 ppm may cause excessive corrosion or deterioration to pool equipment and surrounding surfaces in and around the pool.
  • The cell tests the salt level every 12 hours. So it may take 12 hours for the salt level on the cell to change after adding salt.

What is the IntelliChlor Cycle Time?

The Intellichlor cycles the % generation in 5 minute intervals. If the % generation is set to 50% the cell will generate chlorine for 2.5 minutes and be idle for 2.5 minutes.

Should the IntelliChlor Cell be Acid Cleaned?

We discourage routine acid cleaning of SWG cells unless other less damaging methods fail to remove scale. SWG How It Works discusses alternate ways to clean a cell before you should use acid.

Pentair sells the ACID CLEANING KIT (P/N 523103) that is an acid washing stand and an O ring to cap one side of the cell. The Acid Cleaning Kit Instructions direct you to create an acid solution by mixing one quart of muriatic acid with one gallon of tap water in a plastic five (5) gallon bucket.

ALWAYS add acid to the water, NEVER add water to the acid. Always wear eye protection and use rubber gloves. Always work in a well-ventilated area.

Pentair Intellichlor Acid Cleaning Stand.png

What to Do If Easy Touch/ScreenLogic Reports Salt Level as Zero

For some reason, unknown to Pentair, minor changes to the system will cause the salt level in the EasyTouch and ScreenLogic to read zero.[10] This is just an error in reporting and the cell should still be working as long as the actual salt level is ok and the cell does not show a "red low salt" light on the cell. I believe that there is a timing issue in the circuitry that reports the salt reading to the EasyTouch. It is obvious that the cell knows what the real salt level is. This has been "Fixed" by the following actions:

  • Just shutting off and rebooting the ET
  • Replacing the flow switch
  • Replacing the ET's surge card (power supply for the cell)
  • Replacing the ET's main board
  • Replacing the salt cell itself.

Connecting IntelliChlor to an IntelliConnect System

The Intellichlor Power Center connects to the IntelliConnect using the RS-485 yellow and green data link.

The IntelliConnect will only allow the IntelliChor to generate when the pump is running.

For the Intelliconnect to control your Intellichlor settings, you must also have a separate temperature sensor installed. It is surprising to learn this, since the Intellichlor has its own temp sensor,[11]

What Does the Intellichlor Power Center Do?

IntelliChlor Power Center old style.jpg

The ICXX cells are powered by either a stand-alone Power Center box or a transformer that is integrated with an Easy Touch or IntelliCenter Load Center.

Output: 22-39 VDC @ 6 AMPS maximum from the Power Center. [12]

The AC power goes into the power center and through the fuse and then goes into a step down transformer The output of the transformer should be about 28 Volts AC. You should check the you have either 120 VAC or 240 VAC going into the transformer and that you have about 28 VAC going to the board.

The board changes the 28 VAC into about 40 volts DC. If you have 28 VAC going into the board and do not have 40 VDC coming out, the board is bad.

The voltage between the red and black wire on the connector (J7) going to the cell is about 40 volts DC.[13]

How is the IntelliChlor Power Center Wired?

The stand-alone Power Center box can run with 120V or 240V ac power. You have to wire the transformer for 240 volts or 120 volts.

When using 240 volts (often called 220) you connect L1 to the Yellow wire and L2 to the White wire and connect the Blue/Violet to the Black wire with a wire nut.

When using the 120 volts, you connect the hot wire to the Yellow and Black wires and the Neutral to the Blue/Violet and White wires.

The power supply for ichlor and intellichlor contains a 4 wire communication cable that has a 22-39 volt DC output at 6 AMPS maximum (red and black as shown in the manual).[14]

Power Center Glass Fuse

These power supplies are known for having faulty fuse holders. So lack of power could be the fuse or the fuse holder itself. You can temporarily jumper across the fuse holder and see if things fire up. If they do replace the fuse and fuse holder.[15]

Some Power Centers have a glass 10 amp slow blow fuse. The specifications are:

  • AG3, slow blow, 10 amp, 250vac (. 25 inch x 1.25 inch or 6.35mm x 31.75mm)

They have been found on Amazon and the old fashioned hardware store in town.[16]

Power Center Green Light Off

There is a green LED on the power center PCB board indicating power is on. If the green LED is off first check the fuse.

There have been some problems with the fuse holder, where the fuse was good but the AC volts did not pass through the fuse holder itself.[17]

If the fuse tests good then jumper the fuse and see if you get the green light. If you do then replace the fuse holder.

Power Center PCB

IntelliChlor SWCG PCB.jpg

The IntelliChlor power center PCB is either in the automation load center or in the separate Power Center box.

To the right is an IntelliChlor power supply board in an Easy Touch system. You can see the green power LED glowing in the upper right. Yours will be different, but similar. You can see the two red wires coming into the board that bring in the AC volts and the DC volts go out at the connector on the left hand side.

When the bridge rectifier is bad, the breaker should pop without the cell connected.

The PCB is Pentair Kit Surge Board PC100 521034Z.

IntelliChlor Cell Connector

See Corroded power connector on Pentair IC40

Surge Board Repair

There are two functions for the surge board:

  1. Protect the communication lines between the controller and chlorinator from electrical surges. This is done using clamping diodes and is normally non-destructive, but sometimes the diodes are overloaded and fail. (Some pictures in this forum of this kind of failure).
  1. Rectify the 24VAC from the transformer through a full-wave bridge rectifier to get ~32VDC for the IC40.

The IntelliChlor Power Center and the Pentair IntelliCenter, EasyTouch, IntelliTouch with integrated Intellichlor power have different surge board designs. The automation surge boards are more prone to requiring replacement then the Power Center surge board.

The IntelliChlor Power Center Surge Board looks more robust with a large heat sink...

Pentair IntelliChlor Power Center Surge Board.jpg

then the suge board used in the automation systems...

Pentair Intellicenter Surge Board.jpg

The rectifier failed with a direct short from one AC leg to the Positive voltage terminal on one members surge board in his EasyTouch.[18] At the time a new surge board costs around $250 while the rectifier is a $4 part.

Pentair Surge Board Fail.jpg

The specs for the original rectifier are 25A max, 100v reverse, and 125C operating temp. The replacement is a 35A, 200V, 150C device. He suspects the failure of the original came from overtemp operation over a prolonged time. As part of installing the new device thermal transfer paste was applied to the heatsink of the rectifier, and scraped off the paint in the cabinet where it contacts for a better thermal seal so the entire cabinet can act as a heat spreader.

The original rectifier is a MB251W and the replacement rectifier is a GBPC3502W. They can be found at Mouser.com or Digikey.com.

Even if you have to buy a higher power soldering iron and "solder sucker" to do the repair, you'll still come out way ahead.

IntelliChlor Cell Should Not be Powered When Pump is Off

The flow switch is a secondary safety mechanism. There should be a primary means for the cell not to be powered when the pump is off and there is no water flow. This can be with pool automation equipment or a mechanical timer.

Pentair Manuals say:

The IntelliChlor Salt Chlorinator Power Centers must be interconnected with the pool pump motor power source. This ensures the IntelliChlor Salt Chlorinator and pool pump will switch on and off together. [19]

and

WARNING:CHLORINE GAS BUILDUP CAN OCCUR WITH IMPROPER WIRING: To reduce the risk of personal injury the IntelliChlor® Salt Chlorine Generator (SCG) Power Center must be installed on and wired to the load side of the time clock, electronically controlled switch, or relay load side, so that it will receive power only when the pool pump is on. Otherwise, dangerous chlorine gas buildup can occur. The IECG should never be energized when the pool pump is OFF and water is not flowing through the unit. [20]

Intellichlor Cell Explosions do Happen

Here is one report - Explosion near the SWG

And another - Help,, my pipe exploded !!!

https://www.troublefreepool.com/threads/exploding-pool.53538/

  1. https://www.pentair.com/content/dam/extranet/nam/product-related/product-manuals/pool-and-spa-equipment/intellichlor/IntelliChlor_Owners_Manual_Version_3_units_after_Nov_2011_English.pdf
  2. https://harwil.com/product/flow-switch-model-q-12/
  3. https://www.troublefreepool.com/threads/salt-question.192625/post-1697763
  4. https://www.troublefreepool.com/threads/intellichlor-ic40-cold-water-shutoff-issue-please-help.248448/post-2176416
  5. https://www.troublefreepool.com/threads/intellichlor-system-status-mode.134913/
  6. https://www.troublefreepool.com/threads/pentair-flow-switch-vs-generic.196347/post-1731458
  7. https://www.troublefreepool.com/threads/intellichlor-zero-salt-reading.189465/#post-1669161
  8. https://www.pentair.com/content/dam/extranet/nam/product-related/product-manuals/pool-and-spa-equipment/intellichlor/IntelliChlor_Owners_Manual_Version_3_units_after_Nov_2011_English.pdf
  9. https://www.pentair.com/content/dam/extranet/nam/product-related/product-manuals/pool-and-spa-equipment/intellichlor/IntelliChlor_Owners_Manual_Version_3_units_after_Nov_2011_English.pdf
  10. https://www.troublefreepool.com/threads/screenlogic-reports-salt-level-as-zero.180867/#post-1598882
  11. https://www.troublefreepool.com/threads/need-a-little-bit-of-pumps-swcg-and-everything-else-help.248009/post-2174063
  12. https://www.troublefreepool.com/threads/intellichlor-power-center-transformer-specs.34669/
  13. https://www.troublefreepool.com/threads/pentair-ic40-with-no-power.148051/post-1307509
  14. https://lesl.a.bigcontent.io/v1/static/pentairintellichloric20saltchlorinator-manual
  15. https://www.amazon.com/Pentair-521248Z-Replacement-IntelliChlor-Chlorinator/dp/B008HLR3H2
  16. https://www.troublefreepool.com/threads/need-a-few-ic40-glass-fuses.198987/post-1758580
  17. https://www.troublefreepool.com/threads/pentair-intellichlor-power-generator.201109/post-1774481
  18. https://www.troublefreepool.com/threads/easytouch-surge-board-repair-ic40.260741/post-2280146
  19. https://www.pentair.com/content/dam/extranet/nam/product-related/product-manuals/pool-and-spa-equipment/intellichlor/IntelliChlor_Owners_Manual_Version_3_units_after_Nov_2011_English.pdf
  20. https://www.pentair.com/content/dam/extranet/nam/product-related/product-manuals/pool-and-spa-equipment/intellichlor/IntelliChlor_Owners_Manual_Version_3_units_after_Nov_2011_English.pdf