I'm not sure what you described is demand defrost. Timer defrost uses a temp sensor on the coil too and goes into defrost mode every x minutes (typically 30-60-90 as set by jumper) if the coil temp is below 35 degrees (or so) and stops defrost mode when the coils hit 60 degrees (or so) or when 10 minutes (or so) have elapsed. This works but it creates a lot of unneeded defrost cycles when it's cold but very dry outside.
Demand defrost attempts to determine if the coils are actually iced up by measuring temperatures, fan current, or air flow. Regardless, you seem to have a defrost problem and maybe an installation problem. If you run the system in cool (and you can stand it) it should defrost the outside coil. But it sounds like you have an installation issue with the breakers tripping. > -----Original Message----- > From: Kaleb C. Striplin via Mercedes > Sent: Sunday, January 08, 2017 12:32 PM > > This system has demand defrost with a sensor on the coil that will put > it into defrost mode when the coil temp falls below 35 after system has > been running for a certain amount of time. I am just wondering if the > sensor is going bad and works most of the time but fails to register it > needs to defrost sometimes and unit ices up and starts pulling more > amps, thereby tripping the breaker. > > > On 1/8/2017 11:29 AM, Mitch Haley via Mercedes wrote: > > I'm thinking there should be three breakers. > > 240 to the outdoor unit > > 240 to the heat strips > > 120 to the air handler > > > > If you have timer defrost, your choices are cycling too often most of > the time vs icing up when the relative humidity is high, depending on > how you set the timer. I think mine gave me the choice of 30, 60, or 90 > minutes. > > > > ... _______________________________________ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
