What Should You Look for When Selecting a Salt Chlorine Generator?
Regardless of the brand, all salt chlorine generator (SCG) systems consists of three main components: power supply, cell, and flow protection. The differences between brands lie in how you operate, maintain, and troubleshoot your system. Let's take a closer look at those components and see what differences you need to consider when purchasing a new unit.
The power supply takes high voltage from the mains and changes it to low voltage, which energizes the cell and allows it to generate chlorine. A control board lets you control how much chlorine the cell is generating. Using either a rotary dial or push buttons, you can set the chlorine output level anywhere from 0- 100%. Some systems allow you to adjust the level in 1% increments, while others allow adjustments in 20% increments. Naturally, the 1% incremental control will allow a much finer tuning of the salt system to match the pool equipment’s normal operation. The higher increments may require some adjustments of the pump run times to ensure that you maintain the proper chlorine level.
Power supplies also provide warning lights or other indicators to let the pool operator know of improper operating conditions or damaged components. The ease with which you can interpret a power supply's indicators varies from brand to brand. Whether the supply uses flashing lights, error codes, or digital displays will determine how easily you can identify such problems as high salt levels, cold temperature limits being exceeded, or problems with the power supply itself.
All cell designs are similar and usually consist of a PVC housing and titanium blades with ruthenium oxide coatings. The PVC housing may be either translucent or non-translucent. The translucent housings allow for a visual inspection of the cell’s cleanliness. The blades will vary in size and quantities within the housing. The number of blades and the amount of power going to the cell determines how much chlorine the cell generates. The amount of ruthenium oxide on the blade determines how long the cell will last. Most residential cells are rated for approximately 7,000 hours of life. Commercial cells are rated approximately 15,000 hrs.
Calcium scale formation on the blades is detrimental to cell life and should be prevented. Allowing calcium scale build up on the blades will shorten cell life and reduce chlorine output and efficiency.
Power Supplies are designed with a self-cleaning mode for the cells to help prevent calcium scale buildup. However, if water chemistry conditions are not maintained properly, according to the Saturation Index, calcium scale will build up and will require manual acid washing to rid the cell of calcium.
Two methods of flow protection are available: mechanical flow switch and electrical gas trap. The mechanical flow switch is a device that senses water flow prior to the cell, and pushes a flow paddle towards a magnetic switch. When water flow is correct, the switch sends a signal to the power supply to let it know there is sufficient flow.
The gas trap design requires there to be sufficient flow to evacuate any air or gases that can accumulate within the cell body. Gas traps typically require an initial high flow rate to rid the gases, and then it can operate at lower RPMs. However, the gas trap may still require a higher flow rate than that of a flow switch.
Flow switch designs allow for flexibility in the cell orientation, whereas the gas trap requires the cell to be mounted horizontally. Flow switch designs will work better with variable speed pumps by allowing a lower RPM, and lower flow rate, to activate the flow device.
Finally, it is important to understand the differences between salt systems when making your selection. If you are in an area of high calcium levels (Phoenix for instance), you should consider a system that performs self-cleaning more frequently, or at least allows you to program the self-cleaning mode to run more frequently.
If you do not reside near a pool store, so that you can replenish salt on short notice, you may consider a system that displays the salt level. These systems use a salt sensor and calculate how much salt is needed to maintain proper levels. By observing the display, you can have an idea of how soon you will need to add salt.
Yet at the same time, if you accidentally add too much salt, a system that does not have a high salt limitation will allow you a wider range of operation. Likewise, if you experience unseasonably cold water temperatures, a system that will continue to operate under such conditions will prevent low chlorine conditions, which can allow algae to grow—even with cold water conditions, algae can grow. This will eliminate the need to have to switch to regular chlorine products until temperatures increase. This may be more applicable to pool owners outside of Florida.
Since you are considering a salt chlorine generator for its improved feel of the water, ease of operation, and convenience in maintaining your pool, understanding the differences we have discussed can help you select the perfect unit for your needs.