Cycle Timer
Based on the selection of 2, 4, or 6 cycles per hour, this timer is set to 30, 15, or 10 minutes. This much time must elapse from the start of one cycle before another cycle can start. It serves to impose the cycles per hour limits. It can be defeated for one cycle by simultaneously pressing the FAN and UP buttons.
Ten−Minute Staging Timer
In multistage heating or cooling, this timer prevents any higher stage from turning on until preceding stage has been on for 10 minutes. When staging between compressor and electric heat or between compressor and furnace heat, the time is configurable. The timer is configurable via Option 17. This timer is overridden if temperature error is greater than 5_ (usually due to a large change in desired temperature) and equipment stages up in 60 second intervals.
The ten−minute staging timer does not require the thermostat to change to a higher stage after 10 minutes. If the system is able to meet the demand (maintain setpoint) it may not change stages after the 10 minute timer has expired. If there is sufficient demand for a higher stage at the end of 10 minutes or at any time after the 10 minute timer has expired, the thermostat will energize the next higher stage.
Defrost
Detection of defrost will not work properly if the installer has configured the O/W2/B output to function as a B output. During heat pump heating, a defrost signal shall be considered valid if the compressor output is energized and the defrost signal has been active for less than 15 consecutive minutes. Any defrost signal present for longer than 15 minutes shall be considered invalid.
Heat pump/fan coil systems shall use this input to:
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