How To Set Up an In-Line Salt Chlorine Generator

This guide shows you the steps to take in installing a typical in-line salt chlorine generator. Note: This guide is intended to give you a visual reference to supplement the manufacturer's owner's manual, not replace it. Make sure you read and understand your owner's manual before installing your unit. It will have the most up to date and manufacturer-specific information. An in-line salt chlorine generator generally has two parts: the power unit that supplies DC power for electrolysis, and the in-line electrolytic cell which converts diluted saltwater to chlorine (hypochlorous acid). Some units also have an external flow meter to detect if no water is flowing through the pipe. Although this guide is written with specific references to installing a Compupool Salt Chlorine Generator, most steps can be applied to any in-line salt generator. Also, this guide is written for an inground pool installation. 

1. Your first step is to make sure you have all the items you will need to install your new salt chlorine generator. These will include: items to mount the Control Unit - level, drill, screwdriver; items to wire the Control Unit - voltage meter, screwdriver, wire cutters; items to install the Cell into the piping - hacksaw, file, pvc primer & glue, couplings, cleaning rag.

2. Your next step will be mounting the Control Unit onto the wall close to the pool timer. Make sure that this location is at least 10 feet from the edge of the pool and that the 6 foot DC power cord connected to the Control Unit can reach the section of pipe selected to mount the Cell. The Cell has to be mounted at the end of the return pipe after all other units (i.e. after pump, filter and heater if you have one). In this case we will be replacing an existing Tablet Chlorinator with a Salt Chlorine Generator Cell.

3. Mount the Control Unit bracket at eye level on the wall and, if possible, in an area out of direct weather and sunlight. We are using a level here to line up the bracket.

4. Place the Control Unit onto the bracket and secure temporarily with 2 screws.

5. Your next step is to wire the power cord from the Control Unit to the pool timer. When wiring, be sure to follow local and NEC/CEC electrical codes. CONTACT A PROFESSIONAL ELECTRICIAN IF YOU ARE UNCOMFORTABLE WORKING WITH POWER. Incorrect wiring can cause dangerous shocks and may void your warranty.

6. Before wiring, you will have to check the output power level at the timer going to your pump. It will be either 120VAC or 240VAC. In preparation for measuring your power, TURN OFF THE POWER TO THE TIMER BOX. There should be a circuit breaker before the timer box.

7. WITH POWER OFF, remove the cover over the screw connectors inside the timer box.

8. This picture shows the wiring inside the timer box. Three wires come in from the left of the box. Two are labeled INPUT and one GROUND. Generally, but not always, color of the wire is significant. If the two INPUT wires are red and black, they are both load wires and provide 240VAC. If they are white and black, white is neutral and black provides 120VAC. The green wires provide GROUND. There are 5 terminals in the timer box. The left most, labeled “A”, is NOT USED. The other four are labeled 1 to 4. The INPUT wires are connected to 1 and 3.The GROUND wire SHOULD BE ATTACHED TO THE GROUND SCREW JUST ABOVE TERMINAL "A". IT IS WRONGLY SHOWN IN THE CURRENT PICTURE AS GOING TO "A".The OUTPUT wires are attached to 2 and 4. The OUTPUT wires are currently wired to the pump.

9. To measure your voltage level, TURN ON POWER back on at circuit breaker. Set your digital multimeter to 300 VAC and place the meter's probes on the OUTPUT terminals, 2 and 4. It does not matter which probe is placed on which terminal. Be careful not to let the probes short out between two adjacent terminals. The meter should read close to 240VAC if your power is 240VAC - 120VAC if the timer is using 120VAC.

10. TURN OFF POWER at the breaker and replace the cover.

11. Now you must check how your Control Unit is configured internally. Your Control Unit can be set to operate at either 120VAC or 240VAC to match your voltage at the timer. Control Units are generally shipped from factory in 240VAC configuration. If your timer power is 120VAC you will have to change the VAC power configuration within the Control Unit from 240 to 120. Each manufacturer has their own power configuration. If you are not installing a Compupool Control Unit, see the manufacturer's wiring guide for instructions on internal wiring of the Control Unit

12. To check the configuration of your Control Unit, take the Control Unit off the bracket and take off the Control Unit cover by removing the 6 screws on the base of the unit.

13. If you are installing a Compupool Control Unit and your output timer power is 240VAC, the 240VAC configuration should look like this. The key connections that make this 240VAC are red wire to J12 and orange wire to J8.

14. If you are installing a Compupool Control Unit and your output timer power is 120VAC, the 120VAC configuration should be changed to look like this. For 120VAC the red wire goes to J11 and orange wire goes to J14.

15. Replace and secure the Control Unit cover with the 6 screws. Remount the Control Unit onto its bracket and secure with 4 screws.

16. Your next step is to wire the power cord from the Control Unit to the timer box as show in the picture at left. Red wire to terminal 2, black to terminal 4 and green to GROUND.

17. Attach a minimum 8 AWG copper wire between the bonding lug on the outside of the Control Unit and your pool bonding system. This system should already be in place for your pump. If you are installing a Compupool Control Unit, this bonding lug is shown at the left. Failure to adequately bond your power unit can lead to severe electrical shocks. Note: This bonding wire is installed in addition to your normal grounding process (green wire). You need both per code.

18. You can test the Control Unit now before installing the Cell. Do this test WITHOUT connecting the DC power line to the Cell. Turn POWER ON to the Control Box at the timer box - pump will go on also. The Control Unit lights will go on momentarily then off. Push the ON/OFF button on the Control Unit to turn the Control Unit ON.

19. Your next step is to install the in-line cell. The Cell has to be mounted horizontally and should be placed as the last element in the return line after the pump, filter and heater, if you have one.

20. The Cell should be mounted with the inlet and outlet ports facing down. These ports are marked. Water should flow into the "INLET" port and out though the "OUTLET" port.

21. Make sure the barrel unions are screwed tightly to the cell. Hand Tighten.

22. Cut two sections of pipe about 10". You can buy a large PVC pipe cutter that make a clean straight cut or you can use a regular hacksaw. Just remember to make as square a cut as possible.

23. Debur and clean the outside and inside edges of the two pipes. A file with one side flat and one side round works well.

24. Glue the 10" pipes to the barrel unions. Make sure the pipe and inside of the union are clean. Gluing is a two step process. First apply a thin but even coat of purple primer on each surface to be joined: the outside of the pipe and the inside of the union. After the primer has dried, apply a THIN EVEN coat of glue to both surfaces. Immediately push the pipe all the way into the union and twist 1/4 turn to spread the glue. Hold the pipe in place for 30 seconds until the glue sets. Repeat for the other union.

25. Place 90-degree elbows onto the ends of the two 10" pipes as shown. Do not glue them on. These are placed on to determine how much of a space to cut out of your return line.

26. Measure the distance between the ends of the elbows. It should be 9". Remember that your return pipe will slide inside each elbow 1 3/8" so subtract 2 3/4" off your space measurement. This leaves 6 1/4" for the space to be cut out of the return line. This Cell is part of the larger CPSC36 unit. If you are installing the CPSC24 unit, the space may be shorter.

27. TURN OFF POWER to the Control Unit and pump at the breaker box. Relieve water pressure in the line at the relief valve on the filter.

28. Assuming that you are replacing an existing chlorinator with the salt chlorine generation cell, cut out the existing chlorinator so that there is a 6 1/4" space between the ends of the return line. Depending on your current configuration. you may have to cut out more pipe and then rebuild the piping so that a gap of 6 1/4" is left to install the new Cell.

29. Now comes the tricky part. You have to glue two elbows on the ends of the return piping and place the pipes coming out of the Cell into the elbows before they dry. By steps - prep each elbow and return pipe end with primer and glue.

30. Place the elbows on the return pipes and push them on all the way.

31. Quickly place the pipes from the Cell into the other end of the elbows to make sure the elbows are aligned and spaced correctly with the Cell pipe. The Cell pipes don't have to go on all the way - about 1/2" to 3/4" is sufficient. Just far enough to ensure that the fittings are aligned. Hold them there for another minute to let the glue set.

32. Now take the Cell pipes out of the elbows and apply primer and glue to the Cell pipes and the unglued sides of the elbows. Push the Cell pipes onto the elbows all the way in and hold a couple of minutes until they dry.

33. Wait two hours to let the glue joints fully cure before running water through the piping.

34. Attach the cell plug. Make sure it is pushed on completely as shown at left.

35. Your salt generator cell is ready for operation. Make sure the pump is primed and TURN POWER ON at the breaker box to the pump and Control Unit . If the Control Unit isn't On, turn it ON at the Control Unit.

36. Next you want to add salt to your pool for the Salt Chlorine Generator to act on. The Compupool CPSC/CPA Series is recommended to run at a salt concentration of 3500 ppm. If you are not installing a Compupool unit, check your manufacturer's instructions for their recommended level of concentration . Use a salt that is at least 99.8% pure NaCl. The preferred salt is an evaporated, granulated, food quality, NON-iodized salt. Avoid using salt with anti-caking agents like sodium ferrocyanide, also known as yellow YPS (prussiate of soda. These cause some discoloration of fittings and pool surface finishes. DO NOT use calcium chloride.

37. Using a saltwater test strip, measure the current salt level of your pool. For the Compupool generators, the ideal is 3500 ppm. If the level is low, determine the number of gallons in your pool and add salt according to the Salt Table. For example, if your pool has 15,000 gals of water and your current salt level is 2500, you need to add 125 lbs of salt.

38. Before adding salt to your pool, be sure to TURN OFF the salt chlorine generator at the Control Unit. The generator should not be turned on until the salt is completely dissolved. Leave the PUMP ON to circulate the water and help dissolve the salt.

39. When you add salt, DO NOT pour it directly into the skimmer. For best results empty the required salt into the shallow end of the pool and let it dissolve and circulate through the main drain. The salt may take about 24 hours to dissolve completely. Finer grades of salt will dissolve faster.

40. After the salt has dissolved, turn on the salt chlorinator. Check to see that the salt level is around 3500 ppm. Your pool should be maintained at around this level. A low salt level below 3000 ppm reduces the efficiency of the salt generator which results in low chlorine production. A high salt level above 4500 ppm can rapidly reduce the longevity of the cell.

If you have any other questions about pool and spa products please do let us know - we are here to help! 

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