heat pump defrost mode

Question

North Florida usually stays above 45 Farenheit: the heat pump defrost mode is rarely needed. My neighbor's controller board has been replaced two times and we would like drill down to root cause.

1. How does one determine if the system is of the "Time-Temperature" type or "Demand defrost" control?
2. What can be done to protect the board from over / under voltage?

Answer 1

1. I'd check with the manufacturer and/or their documentation, personally; much easier than trying to figure it out from the machine.

2. Is over voltage sufficient to cause damage actually occurring? If so you have bigger problems than the defrost cycle. Undervoltage (except perhaps actively cooled) rarely causes damage to the electronics; things just don't run properly.

Answer 2

Defrost mode would not kill the control board.

Frequent power out (spikes) could do that.

You could install a AC-line filter to minimize the spikes.