UltraTemp Heat Pump short cycles

[DoDo1975]

Moved from here .. Pentair UltraTemp Heat Pump short cycles when using RS485 remote setting

Has anyone with a newer Easytouch seen a similar problem? As my pool comes up to temperature, it will cycle on and and off for hours. The easytouch is sending the command, not a heater issue.

I have a Pentair Mastertemp 250k connected to easytouch with the firemans switch.

This capacitor that was supposed to come with the New Easytouch, did it come separately or was it built in. Its possible that I may have missed it in a bag?

 

[Jimrahbe]

D,

I was under the impression that the cap fix was for when the heater was under RS-485 control..

I have no heater, so take what I say with a grain of salt, but I am not so sure you have a problem.. It appears your pool temp is stable and the air temp is going down as the heater is trying to keep it at your set point.

Let's see what our other members have to say...

Thanks,

Jim R.

 

[DoDo1975]

I should note, I am using RS 485 to an screenlogic interface, but not to the heater.

 

[Jimrahbe]

D,

Did you look at the tech note in the original post. It shows adding the cap between the two leads of the water temp sensor and the link by the OP shows the cap you would need. It can't hurt to try it..

Thanks,

Jim R.

 

[csconner]

I don’t understand

if the EasyTouch is not connected via RS-485 it’s not controlling the heater other than energizing the fireman switch to power on the heater.

Based upon your screen shot the heater is coming on to heat to set temp, turns off, come back on once pool temp drops 2/3 degrees below set point.

as outside temp drops heater needs to run ,more often to get to set temp. Seems like normal op to me.

So, I still don’t understand, you have a MasterTemp heater, not a HP, what do you believe the issue is?

update, after reading the previous post, interesting I’d never seen that Pentair Tech Bulletin. Mmmmmm…

 

[DoDo1975]

I believe the issue is of no hysteresis. When a heater is cycling every couple of minutes, I do not think this is intended behavior. I can watch the temperature on the easytouch display move between my setpoint and 1 degree less, then back to my setpoint in the span of two minutes, with heater off, heater on, heater off commands being correctly sent based on these temperature readings. I cannot tell if the sensor is measuring at a better resolution than 1 degree because the screen does not show me.

I will try the capacitor, but I suspect that the temperature readings are correct and the band around the setpoint is the problem.

 

[Jimrahbe]

D,

I tend to agree with you, and on the surface, adding a cap to the temp probe connection should have little to do with the RS-485 control..

Please let us know how this turns out.

Thanks,

Jim R.

 

[ajw22]

The IntelliCenter has a temperature differential setting for the UltraTemp to set a wider band where the HP cycles on and off.

I would check if Pentair added that feature into recent releases of the ET firmware.