SWCG controllers

[ccbill]

Generally is it safe to say that the controllers (power supply) for swcg's are designed as a constant current source?

 

[ajw22]

No, different SWGs control voltage and current differently.

 

[JamesW]

Generally is it safe to say that the controllers (power supply) for swcg's are designed as a constant current source?

Pentair tries to keep the current constant by changing the voltage.

Jandy might try to keep the current constant by changing the voltage.

Hayward keeps the voltage constant and the current varies based on the water temperature and the salinity.

These models use an On/Off cycle based on a percentage.

Some Australian models vary the power rather than the On/Off times.

 

[ccbill]

How about:
Regardless of whether the current or voltage to the cell is being controlled , the current is being measured and acted upon.

 

[JoyfulNoise]

Not sure I understand the wording of your question but if you are asking if SWGs are electrically safe then the answer is -

Yes, as long as the they are properly installed to code with the appropriate wiring and bonding used.

I have yet to see an article of anyone randomly being electrocuted by an SWG that was properly installed.

 

[markayash]

Not sure I understand the wording of your question but if you are asking if SWGs are electrically safe then the answer is -

Yes, as long as the they are properly installed to code with the appropriate wiring and bonding used.

I have yet to see an article of anyone randomly being electrocuted by an SWG that was properly installed.

Is your first lesson dealing with electricity “ water and voltage don’t mix especially salt water”

It’s been a long time but does “pure clean water” conduct ?

 

[JoyfulNoise]

Pure water has a resistance of approximately 18.9 mega-ohms. That is double distilled, deionized water delivered in non-metallic piping. “City water” that is clean and low mineralization has a resistance of about 0.1 mega-ohm. The stuff in your pool is a lot lower resistance than city water.

The first lesson I learned in EE-101 was -

V = I • R

Which then shortly turned into -

 

[markayash]

Pure water has a resistance of approximately 18.9 mega-ohms. That is double distilled, deionized water delivered in non-metallic piping. “City water” that is clean and low mineralization has a resistance of about 0.1 mega-ohm. The stuff in your pool is a lot lower resistance than city water.

The first lesson I learned in EE-101 was -

V = I • R

Which then shortly turned into -

I bet that guy who does the voltage videos James post would never have a salt pool. Heck he probably has a belt driven pump

 

[Jimrahbe]

Matt,

I can only assume that means there is zero percent chance of a SWCG shocking anyone...

Thanks,

Jim R.

 

[ccbill]

what the S?

Not sure I understand the wording of your question but if you are asking if SWGs are electrically safe then the answer is -

Just wondering how the controller worked.

 

[JamesW]

Regardless of whether the current or voltage to the cell is being controlled , the current is being measured and acted upon.

Pentair and Jandy measure the current and adjust the voltage to try to keep the current within a specific band.

 

[JamesW]

Ultrapure Water without any impurities will still have conductivity due to of the presence of H⁺ and OH^- ions due to the self-ionization of water.

As soon as you introduce positively and negatively charged ions, the conductivity is increased by quite a lot.

Water temperature also has a significant effect on the conductivity or resistivity.

Ultrapure water has a conductivity of 0.055 µSiemens/cm or a resistivity of 18.18 mΩ·cm at 25 °C.