Spectra watermaker - salinity probe orientation

[AlfredJ]

We have Catalina 300 mk II, and now after only 24h of operation the MPC 5000 control panel indicates too high salinity (>875ppm) of the product water and stops the operation. Other parameters seem normal: GPH: 13.9, Feed water pressure: 83 PSI, Filter condition: Good. What could be the reason?

I have noticed that the salinity probe was installed horizontally by the French company that did the installation, contrary to the instructions in the manual. What is the rationale behind this requirement, and could the malfunction be caused by the wrong orientation of the salinity probe?

[Tellie]

Originally Posted by AlfredJ

We have Catalina 300 mk II, and now after only 24h of operation the MPC 5000 control panel indicates too high salinity (>875ppm) of the product water and stops the operation. Other parameters seem normal: GPH: 13.9, Feed water pressure: 83 PSI, Filter condition: Good. What could be the reason?

I have noticed that the salinity probe was installed horizontally by the French company that did the installation, contrary to the instructions in the manual. What is the rationale behind this requirement, and could the malfunction be caused by the wrong orientation of the salinity probe?

Not sure what orientation you are talking about as the salinity probe will only go in one way. But regardless, there are two possible problems. Either your membrane is bad or you need to re-set the parameters on the control board itself. But first you would need a hand held TDS meter to get a true reading of the product water being made. If you have any questions you can call me anytime.

Halden Marine Services – Marine Watermakers, Solar Panels, Wind Generators
(954) 515-7077

[Jsta_Rebel]

Before spending money on buying new membranes, I would suggest doing the following.
1. Check if the permeate conductivity alarm is timed on the control panel and increase the time before shut down, or increase the number to 900 temporarily. Membranes "wash down" and it takes time for them to reach the set number and it could be that the system is simply not allowing enough time for this process.
2. The conductivity probe (salinity) will not read properly if installed incorrectly. It should be installed so that the permeate (product) water runs into it using a T connection and not hooked into a water line where the water just passes over it. Air, or not being totally submerged into the water can effect the reading. Considering that you say it is installed incorrectly, I'd try this first.
3. Do buy a hand held conductivity meter as Tellie suggested to check everything (they are cheap) or you can also buy a bottle of "conductivity standard solution" to test that your conductivity monitor is operating correctly or if calibration is needed. Possibly a probe replacement. For a quick check, but a bottle of water, pull the probe and stick it into the bottle to see what it reads. If under 100, it's probably reading correctly.
4. you can also bypass the conductivity alarm inside of the panel if you find the probe bad or even if you wish or need to make water by tracing the conductivity wires in the panel and either jumping the probe connections with a small jumper wire, or disconnecting one of the conductivity wires. this will depend if they are connected using a N/O or N/C connection.

Hope this helps helps.

www.tsgwater.com

[AlfredJ]

Thanks for the suggestions. According to Spectra manual the salinity probe should be installed in vertical position, now the installation is such that it is in horizontal position. However, this is apparently not the problem: Spectra technicians here in Spain found out that the product water is good, resetting of the settings does not help, and the problem remains after changing a new probe. When the water maker is started to run, probably a bug in the software (or a fault in the circuit board) causes the salinity reading to jump abruptly from the initial good value to over 1000.

The problem has now been referred to Spectra in the US, and I am hoping that the solution, whether it is a new software, new circuit board, or both, will be found within the guarantee, as the watermaker is only two years old.

[Tellie]

Originally Posted by AlfredJ

Thanks for the suggestions. According to Spectra manual the salinity probe should be installed in vertical position, now the installation is such that it is in horizontal position. However, this is apparently not the problem: Spectra technicians here in Spain found out that the product water is good, resetting of the settings does not help, and the problem remains after changing a new probe. When the water maker is started to run, probably a bug in the software (or a fault in the circuit board) causes the salinity reading to jump abruptly from the initial good value to over 1000.

The problem has now been referred to Spectra in the US, and I am hoping that the solution, whether it is a new software, new circuit board, or both, will be found within the guarantee, as the watermaker is only two years old.

Again, the orientation of the salinity probe won't make any difference. You can tell anyone at Spectra J.T. said so. Before you go too far, make sure you have the correct Salinity probe that matches your version of the MPC board. There are several ones and they do not all work on all the boards.


Halden Marine Services – Marine Watermakers, Solar Panels, Wind Generators

[AlfredJ]

Apparently it is a glitch in A37 software that I have in my watermaker. Unfortunately updating the software to the more recent version A39 requires the change of the circuit board which is an expensive business. The good news is that Spectra has agreed to replace the circuit board within the warranty.