Solved: AquaCal heat pump causes IntelliFlo pump to shut off

[pjt]

Just got a new AquaCal SQ150VS and everything works fine in stand-alone configuration. However, when I attempted to control the heat pump with automation (IntelliCenter), when the compressor started up, the IntelliFlo pump shut down. The IntelliFlo started again by itself around 30 seconds later, and then the process repeats itself endlessly. As far as I can tell, the control cable is connected correctly and things are setup correctly in IntelliCenter. Any ideas?

 

[Jimrahbe]

pjt,

I can't think of how the heat pump can shut down the pump...

What happens to the pump's display when the pump stops..?

Where does the the heat pump get its AC power?

How is the heat pump being controlled by the IntelliCenter?

Thanks,

Jim R.

 

[pjt]

What happens to the pump's display when the pump stops..?

Shows the normal message "Display Not Active!".

Where does the the heat pump get its AC power?

It has it's own dedicated 240V supply.

How is the heat pump being controlled by the IntelliCenter?

There is a 2-wire control cable connecting the two. Within IntelliCenter, the heat pump is setup as "UltraTemp" (to enable heat and cool modes). Seems to be good communication between IntelliCenter and the heat pump since I can turn the heat pump on via IntelliCenter.

 

[pjt]

I called AquaCal and they said it was a problem with Pentair.

I called Pentair and they said it was a problem with AquaCal.

 

[Jimrahbe]

pjt,

What kind of control cable between the IntelliCenter and the AquaCal? I assume it is just connected to the Gas heat connection and not an RS-485 cable.

I did look up the manual for the AquaCal and it does seem to have an RS-485 bus, but that means that both Pentair and AquaCal can speak the same "code"... I find that doubtful, but don't really know if they can talk to each other or not...

One of the major reasons they we don't recommend mixing brands, when the units need to communicate, is the "It's always the other guys problem" syndrome..

Thanks,

Jim R.

 

[pjt]

What kind of control cable between the IntelliCenter and the AquaCal?

It's a 4-wire cable, but only two of the wires are used. It's the thin yellow and green wires in the photo. Is that considered RS-485?

 

[Jimrahbe]

pjt,

You have it connected via an RS-485 cable.. The problem is.. Does it speak the same code that Pentair does??.. On the surface, since the heater manual talks about Pentair, you would assume it does.. But.. Does it work with the IntelliCenter??? Or does it work with the older Pentair equipment.

I don't think that the RS-485 connection gives you any real advantage.. Maybe you can get Pentair or AquaCal to figure out the problem, but in the mean-time, I'd use the two wire "fireman's" loop that almost every other heater/automation uses.

Did you go through the AauaCal manual and set it up using their instructions? (I assume yes, but have to ask..)

Thanks,

Jim R.

 

[pjt]

Did you go through the AauaCal manual and set it up using their instructions? (I assume yes, but have to ask..)

Yes.

I'll make some calls next week. Thanks for your help!

 

[JamesW]

Make sure that the data wires are not reversed.

If the data wires are reversed, it can interfere with the communications system.

If the pump loses communications, it can shut down.

https://www.aquacal.com/wp-content/uploads/manuals/landingpage/air_source_installer_hp9/en-us/Content/Resources/CURRENT/LTP0114.pdf

 

[JamesW]

Maybe the voltage is dropping when the heat pump is turning on.

Check the voltage at the pump before the pump turns on, when the pump is on and then when the heat pump turns on.

Are there any errors on the pump screen?

 

[JamesW]

There are multiple places to check for the pump status and error codes.

Check the status of the pump as the heat pump is activated and watch for any error codes.

If the pump is shutting off, there will probably be a code somewhere.

https://www.pentair.com/content/dam/extranet/nam/pentair-pool/residential/manuals/automation/intellicenter/intellicenter-users-guide.pdf

 

[pjt]

@JamesW Thanks for all your help!

 

[JamesW]

Check the contactor on the heat pump.

If the compressor is locking up, the amperage will go very high and the voltage will drop out, which can cause the pump to shut off.

This will usually cause the contactor to begin to show signs of overheating.

Pentair UltraTemp 120 H/C Compressor Issue

Let me start out, the unit is brand new, installed January 2020. I thought I had the heating temperature swing issue resolved, but no joy. The set temperature for heat is 86° and the unit will heat until 90° to 92°. The control board and temperature probes have been replaced several times(4...

www.troublefreepool.com

 

[pjt]

Update:

Tried disabling automation and operating in standalone mode. Same problem appears where the IntelliFlo shuts off when the compressor reaches its operating speed. So, I don't think this is an automation/IntelliCenter issue.

 

[JamesW]

Did you check for error codes?

 

[pjt]

I think I have it fixed.

I checked for error codes on the pump display (there were none). While I had the IntelliFlo disconnected from IntelliCenter, I checked the "Priming" setting and it had somehow reverted to "Enabled". The "Priming" setting caused me problems before (IntelliCenter Initial Impressions / Not Working Well). I disabled priming, reconnected the RS-485 cable to the IntelliFlo, and rebooted the IntelliCenter panel. Everything now works fine and I'm able to control the AquaCal with IntelliCenter.

I'm going to try it again tomorrow before officially declaring victory, but I'm pretty confident the problem is solved.

 

[JamesW]

Why would priming cause the problem?

I suspect that there is probably a voltage problem.

I would measure the voltage as the heat pump is coming on.

 

[pjt]

Why would priming cause the problem?

I don't know. Maybe before the compressor comes up to full speed it sends a query to ensure the pump is primed and operating.

Tested everything again today and it all works as it should.

 

[JamesW]

The IntelliFlo uses the power to determine flow, priming and SVRS.

A heat pump pulls a lot of current, which changes the voltage, which alters the power of the pump in a way that might be affecting the power monitor and it might be interpreting the power change as a flow change.

In my opinion, this points to an excessive voltage drop, which might be due to a defect in the compressor or a possible defect in the power supply.

I would connect a true RMS voltage meter to the pump and watch the voltage with the pump off, as the pump turns on and then as the heat pump turns on to see if it is experiencing an excessive drop.

 

[pjt]

Will do, thanks!