Envision Peripherals Series - Manual (Page 16)

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NS SPLIT INSTALLATION MANUAL
Heating Operation
Note: At first power up, a four-minute time delay is employed before the compressor is energized.
Heat, 1st Stage (Y1)
The compressor and loop pumps are energized 10 seconds after the Y1 input.
Heat, 2nd Stage (Y1,Y2) Dual Capacity Units
The second stage compressor will be activated 5 seconds after receiving a “Y2” input as long as the minimum first stage
compressor run time of 1 minute has expired.
The Comfort Alert will delay the second stage compressor until 5 seconds after it receives “Y2” from the board.
Cooling Operation
In all cooling operations, the reversing valve directly tracks the “O” input. Thus, anytime the “O” input is present, the
reversing valve will be energized.
Cool, 1st Stage (Y1, O)
The compressor and loop pumps are energized 10 seconds after the Y1 input.
Cool, 2nd Stage (Y1, Y2, O) Dual Capacity Units
The second stage compressor will be activated 5 seconds after receiving a “Y2” input as long as the minimum first stage
compressor run time of 1 minute has expired.
The Comfort Alert will delay the second stage compressor until 5 seconds after it receives a “Y2” from the board.
Fan Only Operation
The Fan Only mode is controlled directly from the unit thermostat to the unit air handler. No input is given to the micro-
processor to operate the fan function.
Lockout Conditions
During lockout mode, the appropriate thermostat lockout LEDs (if available) will illuminate. The compressor and loop
pumps are de-energized and if the thermostat calls for third stage heating, emergency heat operation will occur.
Lockout modes of any kind can be reset at the thermostat after a 5-second waiting period, which restores normal
operation.
High Pressure
This lockout mode occurs immediately when the normally closed safety switch is momentarily opened.
Low Pressure
This lockout mode occurs when the normally closed switch is opened for 30 continuous seconds.
Freeze Sensing (Water Flow)
This lockout mode occurs when the freeze sensing thermistor temperature (located between the TXV and coax) is at or
below the selected freeze sensing point (well 30°F or loop 15°F) for 30 continuous seconds.
The unit also contains a secondary freeze sensing sensor located on the entering water line of the unit. If the loop
reaches a temperature of 20°F the secondary freeze sensing sensor will cycle the loop pumps "on" until the loop tempera-
ture rises to or above 25°F.
Modes of Operation