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Infinity Controlled low ambient cooling:
This unit is capable of low ambient cooling without a kit ONLY
when using a complete Infinity system. 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 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 (4.44
_
C) OAT. Fan
will cycle based on coil and outdoor air temperature. A crankcase
heater
must
be installed. See Product Data for accessory part
numbers on appropriate unit size and series.
Infinity controlled low ambient mode operates as follows:
S
Fan is OFF when outdoor coil temp is < (outdoor air
tempe 3
_
F/--16.11
_
C) or outdoor fan has been ON for
30 minutes. (Fan is turned off to allow refrigerant system to
stabilize.)
S
Fan is ON when outdoor coil temp > (outdoor air tempe
25
_
F/--3.89
_
C) or outdoor coil temp > 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.)
S
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.
Standard Thermostat low ambient cooling mode:
The following optional accessories must be installed for low
ambient operation in standard thermostat mode:
S
Low Ambient Pressure Switch Kit
S
Evaporator Freeze Thermostat
S
Winter Start Control
S
Crankcase Heater
The fan motor is a ball bearing type and does not need to be
changed. A crankcase heater
must
be installed. See Product Data
for accessory part numbers on appropriate unit size and series units.
24AN
B
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