So, I have had many issues with my heat pump/AC/Air Handler system. I happen to have a micrologix 820 I think, a vfd and a 3 phase motor. I would like to make sure my program for control includes all the elements I need. So the circuit boards replacing them, as well as the multispeed motor are astronomical in price now.
My understanding as follows. Outdoor/Compressor unit is always in heating mode, the valve, unless you call for cooling. So Tstat calling for heat, or cooling will start the compressor and cooling fan. At some predetermined time period, the valve reverses to de-ice. What is that time period set for approximately ? There should be a high and low pressure switch to stop the compressor to prevent damage. I may bring a parallel signal into my plc for monitoring. So I program 1 relay out to start the fan and compressor outside. This will be in series with the pressure switches. Fan on will be if compressor is on. I have a pid to control my fan inside. It's an 1150 rmp motor. What should I use as Minimum speed ? Any thing you know that I am missing plz feel free to add
My understanding as follows. Outdoor/Compressor unit is always in heating mode, the valve, unless you call for cooling. So Tstat calling for heat, or cooling will start the compressor and cooling fan. At some predetermined time period, the valve reverses to de-ice. What is that time period set for approximately ? There should be a high and low pressure switch to stop the compressor to prevent damage. I may bring a parallel signal into my plc for monitoring. So I program 1 relay out to start the fan and compressor outside. This will be in series with the pressure switches. Fan on will be if compressor is on. I have a pid to control my fan inside. It's an 1150 rmp motor. What should I use as Minimum speed ? Any thing you know that I am missing plz feel free to add