Jandy Temp sensors

[kd9917]

Does anyone know if the Jandy temp sensors are NTC Thermistor Probe. I wanted to use this probe (Probe_tech_sheet) to replace a Jandy 7785 sensor.

Has anyone used this sensor to replace a Jandy sensor?

Thanks for any info

Ken

 

[ajw22]

As long as it is a 10K thermistor, which it looks like that one is, it should work.

How long is the wire? If you splice wire into it be sure it does not add resistance to the circuit.

 

[kd9917]

Yes its a 10K thermistor, I just wasn't sure if the Jandy sensor was also a "NTC". Jandy seems quite intentional in not sharing technical info on their products. The wire is only 24" so I was planning to properly solder on an extension to reach automation box.

 

[ajw22]

Nah, NTC is way too sophisticated and expensive for the pool industry to use.

 

[kd9917]

I think NTC are the most common/standard temp sensors, the one I am looking to use is NTC. Better phrasing of the question would have been, "Does Jandy not use a NTC?"

 

[ajw22]

Looking into it more it looks like NTC is the standard 10K temperature sensor used. Although I have never seen any pool company use NTC in their specs.

 

[MSchutzer]

There are dozens of listings on Amazon for cheap knock-off sensors that work just fine and are under $15 dollars.

Just search for “temperature sensor for pool”, these are all the same form factor as the Jandy, Pentair, or Hayward temp sensors as they all use the same 10k ohm NTC sensor.

These are much cheaper than from any of the ones from the vendors and you can get several for spares and still save money.

I‘m using one of these for the solar temp sensor on my Jandy system as the system bundle only came with 2 genuine Jandy 7790 sensors.

 

[MSchutzer]

And NTC just means negative temperature coefficient. This means the resistance goes down as the temperature goes up. All the automation systems use the same sensor and if you look at the resistance verses temperature chart (a the one that gets posted here every time someone has a problem with their heater‘s temp control) you will see that at 25 degrees C the sensor value is 10k ohms and the resistance drops with increasing temperature.

 

[kd9917]

Thanks for your responses.