Solved: AquaCal heat pump causes IntelliFlo pump to shut off

[pjt]

Electrician came over to check out the problem. Heat pump and IntelliFlo are wired separately to the main panel. No IntelliFlo problems when the heat pump (or air conditioners, which draw more power) are started up.

 

[JamesW]

Do you have the voltage readings with the pump off, as the pump turns on and then as the heat pump turns on?

With no errors being reported, it's definitely odd that the pump would turn off as the heat pump turns on.

Did the electrician check the starting amperage and the heat pump contactor?

Maybe it's a comm wire issue?

Try connecting the yellow, green and black wires, but not the red wire.

Make sure that the wires are in the correct order.

 

[pjt]

Problem came back. Same symptyoms.

However, I noticed all my RS-485 equipment was wired to comm ports on the expansion card. One of the comm ports on the main board was open, so I moved the heat pump wires there and everything works properly now.

 

[rstrouse]

RS485 is dependent on differential voltage. This makes it very robust but at the same time susceptible to bad connections. If there is a loose connection where the voltage on one side or the other (yel or grn) is loose or not making good contact the IC will get intermittent garbage on the bus. In many cases this will seem random or even effect other equipment on the bus. Common things to look out for are loose wires or multiple wires in the same port especially if they are not the same gauge. Its pretty easy to have one of the wires in the bundle make good contact where another does not. Also, in IntelliCenter if you have the IntelliChlor surge board installed, there are two more comm ports available on that board that can be used.