An algorithm for setting Fleck 5600 SXT parameters

[groston]

There is some great information here related to setting the controls for a Fleck 5600SXT meter, but it seems to me that this information could be presented in algorithmic form, i.e., provide a ‘form’ into which one places certain numbers, followed by a set of equations that yield the appropriate settings. Though my level of expertise is certainly far less than that of the regular contributors, the following is my attempt to create such a form. Please fix the mistakes that I have certainly made. (My intent is to create a simply web form that operationalizes the following once the bugs are worked out.)

For a twin tank system.

Information needed:

• Cubic feet of media (per tank)
• Injector number:
• Brine flow rate (BLFC):
• Drain line flow rate (DLFC):
• Water hardness (H) (grains):
• Water pressure (psi):
• Average daily water consumption (gal):

Step 1: Determine flow rates
Using the chart in the service manual that corresponds to the injector, write down the following numbers:

• Brine draw rate (gpm):
• Rinse rate (gpm):
• Total flow (gpm):

Step 2: Select desired system salt efficiency using the following table (data from http://www.watertreatmentguide.com/achieving_brine_efficiency_in_softening.htm)

lb salt (per ft3 of media) | capacity
6 | 21,700 × Cubic feet of media
7 | 23,800 × Cubic feet of media
8 | 25,200 × Cubic feet of media
9 | 26,700 × Cubic feet of media
10 | 27,500 × Cubic feet of media
12 | 29,200 × Cubic feet of media
15 | 30,800 × Cubic feet of media

Step 3: Determine how much salt is needed per recharge cycle using the following equation
Salt needed = Cubic feet of media × Desired salt efficiency
Salt needed (lb):

Step 4: Calculate the number of gallons of brine needed using the following equation
Gallons of brine = salt needed / 3 (round up or down to integral multiple of BLFC)

Step 5: Calculate actual system capacity
Look up value from table, using Gallons of Brine × 3 as the amount of salt. If the amount of salt is not an integral value, interpolate to get the actual capacity. For programming the controller, divide the capacity by 1000.
C:

Step 6: Calculate brine fill time using the following equation
Brine fill time (BF) = Gallons of brine / Brine flow rate
BF:

Step 7: Calculate the brine draw time using the following equation
Brine draw time = Gallons of brine / Brine draw rate

Step 8: Calculate the brine draw and rinse time using the following equation
Brine draw and rinse time (BD) = minimum (4 × Brine draw time, 60 minutes)

Step 9: Calculate reserve capacity (needed for other tank regeneration)
RC = 1.1 * (Back wash time + Rapid rinse time) × DLFC + (Brine fill time + brine draw time) × Total flow

Step 10: Provide system performance overview:
Days between recharge: (C - RC) / (H × Average daily water consumption)
Pounds of salt per month: (30/Days between recharge) × Gallons of Brine × 3

Example system:

Cubic feet of media (per tank): 1 ft3
Injector number: #1
Brine flow rate: 0.50 gpm
Water hardness (grains): 43
Water pressure (psi): 55
Average daily water consumption (gal): 80

Step 1:
Brine draw rate (gpm): 0.25
Rinse rate (gpm): 0.45
Total flow (gpm): 0.7

Step 2:
Salt efficiency: 8 lb/ft3

Step 3:
Salt needed: 8 lb

Step 4:
Gallons brine: 3.0

Step 5:
C: 27

Step 6:
BF: 6 minutes

Step 7:
Brine draw time: 12 min

Step 8:
BD: 60 min

Step 9:
RC: 98 gal

Step 10:
Days between recharge: 7.8
Pounds of salt per month: 35

 

[Bannerman]

I think you will find that most of that has been done except for the injector, BLFC & DLFC info. Here is one example: http://www.qualitywaterassociates.com/sizing.php

 

[Sponsor]

 

[groston]

Bannerman - Thank you. The site you referenced is one of the ones I had visited. It does not, as you point out, provide the detailed programming information that some people are seeking.

 

[ditttohead]

Detailed programming has way too many variables to set up in a simple algorithm. The 5800LXT does this to a certain degree, but it is also a poor choice for water that falls outside of standard norms. Flow rates, water temperature, iron, manganese, tds, pressure, competing ions, pH, seasonal variances, efficiency, desired water quality, application, peak flow rates, and much more... all can be taken into consideration when programming a softener. For the most part, simple programming is all that is needed, but when recurring problems occur, an extensive knowledge and understanding of how these other parameters can affect the way a system works simply cant be add into an algorithm. Even the calculations of a systems ability to soften at the end of the run need to be considered. Your chart would also have to include all the variances on injector draw rates and their efficiency variables. Longer brine draw times increase efficiency, but the curve is very minimal.

This is why most companies eliminate the vast majority of the variables and problems by simply decreasing the efficiency slightly. Setting a softener to 24,000 grains instead of 25,..... (insert each manufacturers variables here, every resin has a slight variance). Competing ions, are you really going to run a spectrometer water analysis and have it analyzed by an engineer in order to use 8# of salt less per year? t is really not that complex, just set it according to the already established industry standards and the system should work fine and fairly efficiently the majority of the time.

 

[Bannerman]

An algorithm for setting Fleck 5600 SXT parameters

For a twin tank system.

If what you mean by 'Twin Tank' is a separate resin and brine tank, that is not considered a twin tank system.
The Fleck 5600 is a single tank valve whereas a Fleck 9000 is a twin tank valve as it controls 2 identical resin tanks which are alternated to provide softening when the other tank's capacity has been consumed and regeneration has been triggered.

Step 9: Calculate reserve capacity (needed for other tank regeneration)

I think you may have misunderstood the purpose of 'reserve capacity'.
Its purpose is a means to ensure that not more capacity is utilized than will be restored.

For example: a 1 cuft softener is installed which has 30K grains total capacity. For salt efficiency, a 6lb setting is chosen which will restore 20K grains of the total capacity so C would be programmed as 20. The family's requirements are 2K grains/day.
With a single tank system, regeneration is typically programmed to occur at 2am after regeneration has been triggered as soft water cannot be delivered while regeneration is occuring.

It would be great if regeneration was always triggered when the last person is preparing for bed at 11pm as no further water would normally be utilized before the 2 am regeneration and therefore, no reserve would be required. In reality, regeneration maybe triggered at any time of day but the softener will continue to provide soft water until regeneration actually occurs at 2am the following morning.

If regeneration is triggered at 1 minute into the first person's shower in the morning, but if no reserve has been programmed, then 22K of capacity will be actually utilized before regeneration occurs, but only 20K capacity will be restored with the 6lb salt setting.

As the restored capacity is 20K grains and the requirements are 2K/day, then regeneration should be triggered when 18K capacity has been utilized (2K reserve) as that should ensure that no more than 20K is utilized, thereby assuring the softener's full capacity is always 'topped up' after every regeneration cycle.

Although a twin tank system is typically programmed as 2 single tank systems, it does not usually require a reserve allowance as the 'stand-by' tank will be immediately alternated to be the 'primary' when the other tank's capacity has been consumed. As the new 'primary' tank will be supplying the soft water requirements without interruption, regeneration of the expended tank does not need to be delayed.

 

[ditttohead]

Very few people seem to get an important point you just brought up. Regenerating slightly ahead of schedule will give the softener slightly more capacity than it's rating for the next cycle. That's why double regenerating "with no water In between" makes little sense if the system has been accidentally depleted of capacity. A simple single regeneration with a little extra water in the brine tank is usually more than adequate to bring a resin bed back into full capacity. Like a battery, a softener can only hold so much of a charge. Any extra is pure waste.

 

[ditttohead]

Very few people seem to get an important point you just brought up. Regenerating slightly ahead of schedule will give the softener slightly more capacity than it's rating for the next cycle. That's why double regenerating "with no water In between" makes little sense if the system has been accidentally depleted of capacity. A simple single regeneration with a little extra water in the brine tank is usually more than adequate to bring a resin bed back into full capacity. Like a battery, a softener can only hold so much of a charge. Any extra is pure waste.

 

[Bannerman]

That's why double regenerating "with no water In between" makes little sense if the system has been accidentally depleted of capacity.

I earlier had questioned that myself.
Even as 15 lbs/salt will restore 30K capacity, I've seen mfg specifications indicate an 18 lb setting to restore full capacity (32K) as most resin when new is specified as 32K/cuft. While some capacity will be lost over time due to bead fracturing and flushing to drain, a double regeneration cycle maybe a method to ensure that any potential capacity beyond 30K is restored, although it would appear an 18 lb salt setting would achieve similar.

Another possible reason for a double regen cycle could pertain to softeners that have remained on-line although they had long run out of salt. As the softener will eventually no longer soften the water flowing through it, it seems that minerals could then potentially build-up within the unit. Upon reactivation of the softener, a double regen cycle would then seem to provide additional cleaning and agitation to initiate the removal of any build-up including calcium and iron deposits.

 

[Gary Slusser]

That's why double regenerating "with no water In between" makes little sense if the system has been accidentally depleted of capacity.

I don't know how a person accidentally does that. There are a few causes of "depleted capacity" but they aren't caused by accident.

A simple single regeneration with a little extra water in the brine tank is usually more than adequate to bring a resin bed back into full capacity. Like a battery, a softener can only hold so much of a charge. Any extra is pure waste.

with a little extra water..... "usually" and what if the extra water isn't enough or is stopped by a safety float system? What if the softener has been sitting there on well water for days/weeks with no salt or.... the metering has been stopped for whatever reason and there has been no backwash of the resin bed since the metering stopped? What about the 'unusual' occurrences where a little extra water isn't sufficient to bring the resin back to full capacity? What then, do you think regenerating without sufficient brine doesn't waste much more water than one additional regeneration? And how will the person know their "little extra water" was too little, and what does the person due that doesn't "waste" water when that happens?