Intelliflo Pump Needs Two Brains

[JamesW]

Solar uses a 10k thermistor mounted on the roof and measures the temperature available on the roof.

The solar temperature sensor connects to the solar temperature input terminal in the automation box.

A 10k thermistor changes resistance based on the temperature. See chart.

https://www.aetsolar.com/literature/Manuals/TempVsResistChart.pdf

If the solar temperature is above the water temperature and the water temperature is below the set point, the solar circuit should be activated.

So, you can use a resistor to trick the sensor into reading a specific temperature.

Use the resistors to trigger the temperature by putting the resistors in parallel.

The 15k ohm resistor would always be in the circuit and you would use a single pole single throw relay and add a 7.5k ohm resistor in parallel.

The relay coil will be activated by the external 24 VAC control signal.

A 15k ohm resistor and a 7.5k ohm resistor in parallel will read as 5k ohm.

You would get a relay that's activated by the available 24 volt power signal.

When not powered, the reading is 15k ohms, which corresponds to 60 degrees Fahrenheit.

When 24 volts is applied to the coil of the relay, the relay switches the 7.5k ohm resistor to be in parallel with the 15k ohm resistor, which is read as 5k, which is interpreted as 106 degrees Fahrenheit.

So, you're just using the resistors in place of the temperature sensor.

This activates the solar mode and the pump changes to the speed set for the solar circuit.

You can even use a three way valve and valve actuator to bypass the fph if you want by connecting the valve actuator to the solar valve controller.

When the solar circuit is triggered, the valve opens to send flow to the fph.

 

[drglanton]

Solar uses a 10k thermistor mounted on the roof and measures the temperature available on the roof.

The solar temperature sensor connects to the solar temperature input terminal in the automation box.

A 10k thermistor changes resistance based on the temperature. See chart.

https://www.aetsolar.com/literature/Manuals/TempVsResistChart.pdf

If the solar temperature is above the water temperature and the water temperature is below the set point, the solar circuit should be activated.

So, you can use a resistor to trick the sensor into reading a specific temperature.

Use the resistors to trigger the temperature by putting the resistors in parallel.

The 15k ohm resistor would always be in the circuit and you would use a single pole single throw relay and add a 7.5k ohm resistor in parallel.

The relay coil will be activated by the external 24 VAC control signal.

A 15k ohm resistor and a 7.5k ohm resistor in parallel will read as 5k ohm.

You would get a relay that's activated by the available 24 volt power signal.

When not powered, the reading is 15k ohms, which corresponds to 60 degrees Fahrenheit.

When 24 volts is applied to the coil of the relay, the relay switches the 7.5k ohm resistor to be in parallel with the 15k ohm resistor, which is read as 5k, which is interpreted as 106 degrees Fahrenheit.

So, you're just using the resistors in place of the temperature sensor.

This activates the solar mode and the pump changes to the speed set for the solar circuit.

You can even use a three way valve and valve actuator to bypass the fph if you want by connecting the valve actuator to the solar valve controller.

When the solar circuit is triggered, the valve opens to send flow to the fph.

This makes a lot of sense. As I am working with my electrician, just where and how will this resistor sequence be connected. Is there a photo of where it will be connected ?

Does it go here with the solar>?

 

[JamesW]

There are three places to connect temperature sensors.

One for air temperature, one for water temperature and one for solar temperature.

It's a two wire sensor.

To the solar temperature sensor input terminal, you will connect both ends of a wire that contains a 15k ohm resistor inline.

You will also connect both ends of a wire that contains a 7.5k ohm resistor.

You will use a simple, cheap relay to open and close the 7.5k ohm wire.

The relay will be activated by the external signal 24 volts.

When the 7.5k ohm resistor wire is open, the solar temperature sensor sees 15k ohms of resistance, which it interprets as 60 degrees.

When the 7.5k ohm resistor wire is closed, the temperature sensor sees 5k ohms of resistance and interprets it as 106 degrees.

At 106 degrees, the solar temperature circuit is activated.

The resistors are cheap and available online.

You can get a simple relay at digikey.com.

In the search feature, you can specify things like coil voltage and spst (single pole, single throw).

 

[drglanton]

It's a two wire sensor.

To the solar temperature sensor input terminal, you will connect both ends of a wire that contains a 15k ohm resistor inline.

Thanks - - Its this a hypothesis or are you aware of other users using this method? It seems solid in it's science.

 

[JamesW]

The other thread that I referenced said that it worked for them.

This will activate the solar circuit, which will change the pump speed to whatever you want and it can also change a valve if you want.

You have to leave the pump on continuously so that the system can get a pool water temperature.

The system won't read the pool water temperature with the pump off because the pool water temperature sensor is in the plumbing and the water temperature in the plumbing is only accurate when the water is moving.

Running at low speed 24/7 costs about $20 per month. So, that's not a problem.

 

[drglanton]

The other thread that I referenced said that it worked for them.

This will activate the solar circuit, which will change the pump speed to whatever you want and it can also change a valve if you want.

You have to leave the pump on continuously so that the system can get a pool water temperature.

The system won't read the pool water temperature with the pump off because the pool water temperature sensor is in the plumbing and the water temperature in the plumbing is only accurate when the water is moving.

Running at low speed 24/7 costs about $20 per month. So, that's not a problem.

Got You . . So this will basically change the speed of the pump but will not stop and start the pump. It has to stay running all the time. And I can still control the pump via the intellicenter! . Sounds like a WINNER@!

 

[drglanton]

The resistors are cheap and available online.

You can get a simple relay at digikey.com.

In the search feature, you can specify things like coil voltage and spst (single pole, single throw).

Great. Do you mind showing me what the relay and resisters look like ? I just want to make sure we are speaking the same language.

 

[JamesW]

Do you want to limit how much heat the fph sends to the pool or do you want to use as much as possible?

If you want to limit the amount of heat the fph sends to the pool, you just set the water temperature maximum in the automation and the automation will ignore any request to activate the solar.

 

[drglanton]

The 15k ohm resistor would always be in the circuit and you would use a single pole single throw relay and add a 7.5k ohm resistor in parallel.

The relay coil will be activated by the external 24 VAC control signal.

A 15k ohm resistor and a 7.5k ohm resistor in parallel will read as 5k ohm.

You would get a relay that's activated by the available 24 volt power signal.

When not powered, the reading is 15k ohms, which corresponds to 60 degrees Fahrenheit.

When 24 volts is applied to the coil of the relay, the relay switches the 7.5k ohm resistor to be in parallel with the 15k ohm resistor, which is read as 5k, which is interpreted as 106 degrees Fahrenheit.

So, do I need the 15k resistor and the 7.5k resistor? I just want to be clear.

 

[drglanton]

The 15k ohm resistor would always be in the circuit and you would use a single pole single throw relay and add a 7.5k ohm resistor in parallel?

 

[JamesW]

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[JamesW]

So, do I need the 15k resistor and the 7.5k resistor? I just want to be clear.

Correct. You need both. When only the 15k ohm resistor is connected, the automation reads the solar temperature as 60 degrees.

When the relay closes, the7.5k ohm resistor will be connected in parallel, which will read as 5k ohm to the system which is interpreted as 106 degrees.

If the pool water temperature reaches the set point, the system won't respond to solar circuit activation.

Does the fhp have a safety protection built in if there is no flow?

Do you want to limit the water temperature to some maximum?

If you have water flowing through the fph continuously, it's going to take up whatever heat the fph puts out.

 

[drglanton]

Correct. You need both. When only the 15k ohm resistor is connected, the automation reads the solar temperature as 60 degrees.

When the relay closes, the7.5k ohm resistor will be connected in parallel, which will read as 5k ohm to the system which is interpreted as 106 degrees.

If the pool water temperature reaches the set point, the system won't respond to solar circuit activation.

Does the fhp have a safety protection built in if there is no flow?

Do you want to limit the water temperature to some maximum?

If you have water flowing through the fph continuously, it's going to take up whatever heat the fph puts out.

There is an over pressure limit switch built-in on all standard compressors. This is the normal way, for example, in a normal unit if the condenser fan were to fail, pressure would rise and it would stop the unit for protection. A condenser fan failing is exactly the same situation as if pump fails on a geo/recovery condenser.

The FPH will make the call for the pump to activate based on a temperature sensor on the FPH

When the AC (or heat pump) unit comes on (based on your indoor thermostat) there is a sensor that lets the system controller know it is on. The controller then starts your pump by communicating with an automation relay on your pump or if you use a mechanical timer, by using a contactor to override the timer, or interface with a variable speed pump. This action starts the pump if it is off, or if it is on, it keeps it on. The pump runs for ~25 seconds to flush the pipe and cure any dry pipe condition, then by using a sensor the controller samples the water temperature. If the water temperature is below the set point that you have selected in the controller, heat recovery is activated. If the pool is warm enough based on your temperature target, the pump is released back to its normal control and the controller resets.

When heat recovery is activated, the heat recovery valve is activated and the AC unit switches from using the normal air-cooled condenser and begins using the FPH titanium heat exchanger/water cooled condenser. At this point all of heat goes into the pool, and the condenser unit fan is deactivated by a relay. Also in this process, any refrigerant that was left behind in the air cooled condenser at the time of switchover is pumped out to the suction line through a meter valve that prevents liquid from entering the compressor. The pump-out procedure keeps all of the refrigerant on the active side of the system. When heat recovery is disengaged, the condenser fan operation is restored and the heat recovery valve(s) switches back to using the air cooled condenser. At this time the FPH water cooled condenser is pumped out to suction in the same manner explained before.

 

[drglanton]

I just need to make sure when the signal is sent from the FPH the pump kicks on at atleast 30 gpm if it is not on. . . .which It will probably already be on if I am running it 24/7.

This may very well be a mute issue if the pump is always running.

 

[drglanton]

Correct. You need both. When only the 15k ohm resistor is connected, the automation reads the solar temperature as 60 degrees.

When the relay closes, the7.5k ohm resistor will be connected in parallel, which will read as 5k ohm to the system which is interpreted as 106 degrees.

If the pool water temperature reaches the set point, the system won't respond to solar circuit activation.

Does the fhp have a safety protection built in if there is no flow?

Do you want to limit the water temperature to some maximum?

If you have water flowing through the fph continuously, it's going to take up whatever heat the fph puts out.

the FPH controller will supply 2 wires (+/-) at 24vac

 

[JamesW]

the FPH controller will supply 2 wires (+/-) at 24vac

Ok, the relay coil takes 24 VAC. When 24 VAC is applied to the coil, the contacts close and complete the circuit with the 7.5 k ohm resistor.

Maybe go with a 20k ohm resistor and a 6k ohm resistor instead of the 15k ohm and the 7.5k ohm.

20k ohms reads as about 50 degrees Fahrenheit. That will give you more control if the water ever gets colder than 60.

A 6k ohm resistor in parallel with a 20k ohm resistor will read as 4615 ohms, which is about 109 degrees.

 

[drglanton]

Ok. But since the FPH is the system taking the temp of the water and activating the 24vac based on those readings, I’m not sure why it matters which resistors it uses. Won’t it simply be controlled by the switch ?

 

[JamesW]

The solar is activated when the pool water is less than the set point and the solar temperature is higher than the water temperature.

By using a 20k ohm resistor and a 6k ohm resistor, we can make the system think that the solar temperature is 50 or 109 degrees to make it turn on or off.

If the system thinks that the solar temperature is 50 degrees it will remain off. When we put the 6k ohm resistor in parallel, the system thinks that the solar temperature is 109 degrees and turns on.

Activating the solar can change the pump speed and rotate a valve if you want.

You can run the pump continuously at 15 to 20 gpm and then have it increase to 30 gpm when solar is activated.

You can also use a bypass so that the water doesn't have to continuously run through the fph.

When solar is off, the bypass is open so that the water doesn't have to go through the fph.

When solar is activated, the bypass valve will close and send water to the fph.

If you want to just run 30 gpm through the fph continuously, that's going to use a lot more power.

Do you have a head loss curve for the fph?

How far will the fph be from the pump?

 

[drglanton]

The FPh will be about 125 feet from the pool.

 

[JamesW]

That's 250 feet round trip. Just use 2" pvc and the distance is not a problem.

I would do a bypass valve that closes when the solar circuit is activated so that the water doesn't need to make the round trip when the fph is off.

Basically, you're just setting up the fph as if it were solar.