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A06526
Fig. 7 - 2-Stage Control Board
Time Delays
The unit time delays include:
• Five minute time delay to start cooling or heating operation
when there is a call from the thermostat or user interface. To
bypass this feature, momentarily short and release Forced
Defrost pins.
• Five minute compressor re-cycle delay on return from a
brown-out condition.
• Two minute time delay to return to standby operation from last
valid communication (with Infinity only).
• One minute time delay of outdoor fan at termination of cooling
mode when outdoor ambient is greater than or equal to 100°F
(37.78°C).
• There is no delay between staging from low to high and from
high to low capacity. The compressor will change from low to
high and from high to low capacity :'on the fly" to meet the
demand.
Infinity Controlled Low Ambient Cooling
This unit is capable of low ambient cooling down to 0°F
(-17.78°C) without a kit - ONLY when using Infinity control. A
low ambient kit is not required, and the outdoor fan motor does not
need to be replaced for Infinity controlled low ambient operation.
The Infinity Control provides an automatic evaporator coil freeze
protection algorithm that eliminates the need for an evaporator
freeze thermostat. Low ambient cooling must be enabled in the
User Interface set up. Fan may not begin to cycle until about 40°F
(4.4°C) OAT. Fan will cycle based on coil and outdoor air
temperature.
Infinity controlled low ambient mode operates as follows:
-- Fan is OFF when outdoor coil temp is less than outdoor
air temperature (+3°F / 1.67°C) or outdoor fan has been
ON for 30 minutes. (Fan is turned off to allow refrigerant
system to stabilize.)
-- Fan is ON when outdoor coil temp is more than outdoor
air temperature (+ 25°F / 13.89°C) or outdoor coil temp
is more than 80°F (26.67°C) or if outdoor fan has been
OFF for 30 minutes. (Fan is turned on to allow
refrigerant system to stabilize.)
-- Low pressure switch is ignored for first 3 minutes during
low ambient start up. After 3 minutes, if LPS trips, then
outdoor fan motor is turned off for 10 minutes with the
compressor running. If LPS closes within 10 minutes,
then cooling continues with the outdoor fan cycling per
the coil temperature routine listed above for the
remainder of the cooling cycle. If the LPS does not close
within 10 minutes, then the normal LPS trip response
(shut down cooling operation and generate LPS trip
error) will occur.
-- The PWM output for both high and low-stage equals the
value for low-stage operation, below 55°F (12.8°C).
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