Residential Air Conditioners and Heat Pumps Using R-22 and Puron® Refrigerant: Application Guideline and Service Manual
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
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Airflow Selections for 187B / 286B / 180B /289B
Using Non-Communicating (Non-Evolution)
Thermostats
Airflow Selection for 58CVA/58MVB Furnaces
The 58CVA/58MVB variable-speed furnaces provide high-and
low-stage blower operation to match the capacities of the compressor at
high and low stages. To select the recommended airflow and for
adjustments to the manual switches labeled SW1-5, AC, and CF on the
control board, refer to the furnace Installation Instructions. The
58CVA/58MVB utilizes a control center that allows the installing
technician to select the proper airflows. The HP switch determines the
airflow during high-stage compressor operation. Airflow for high- and
low-stage can be calculated at either 350 CFM per ton or 400 CFM per
ton, based on the positions of SW1-5.
When using communicating (Evolution) control, dipswitch adjustments
are not necessary on furnaces. Airflows are determined by Evolution
Control setup.
Airflow Selection for FV4 Fan Coils for 180B,
187B, 286B, 289B Using Non-Communicating
(Non-Evolution) Thermostats
The FV4 provides high- and low-stage blower operation to match the
capacities of compressor at high- and low-stage. To select recommended
airflow, refer to FV4 Installation Instructions. The FV4 utilizes an Easy
Select control board that allows the installing technician to select proper
airflows. For adjustments to control board, select appropriate HP SIZE
and CFM ADJUST setting. This fan coil has an adjustable blower off
delay factory set at 90 sec for high- and low-stage blower operation.
For other combinations of equipment consult Product Data.
GENERAL INFORMATION
Low Ambient Cooling
When this unit is operating below 55
_
F /12.8
_
C outdoor temperature,
provisions must be made for low ambient operation.
Evolution Controlled low ambient cooling:
This unit is capable of low ambient cooling without a kit ONLY when
using Evolution control. A low ambient kit is not required, and the
outdoor fan motor does not need to be replaced for Evolution controlled
low ambient operation. The Evolution 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
OAT. Fan will cycle based on coil and outdoor air temperature.
Evolution controlled low ambient mode operates as follows:
• Fan is OFF when outdoor coil temp is < (outdoor air tempe
3
_
F/-16
_
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 > (outdoor air tempe
25
_
F/-3.9
_
C) or outdoor coil temp > 80
_
F/26.7
_
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.
For 180B/289B models, the PWM output for both high and low stage
equals the value for low stage operation below 55
_
F/12.8
_
C.
Defrost
This control offers 5 possible defrost interval times: 30, 60, 90, 120
minutes, or AUTO.
With non-communicating thermostats, these are selected by dip switches
on the unit control board. With communicating thermostats, the
Evolution Control User Interface. The Evolution Control selection
overrides the control board dip switch settings.
AUTO defrost adjusts the defrost interval time based on the last defrost
time as follows:
• When defrost time <3 minutes, the next defrost interval=120
minutes.
• When defrost time 3-5 minutes, the next defrost interval=90
minutes.
• When defrost time 5-7 minutes, the next defrost interval=60
minutes.
• When defrost time >7 minutes, the next defrost interval=30
minutes.
The control board accumulates compressor run time. As the accumulated
run time approaches the selected defrost interval time, the control board
monitors the coil temperature sensor for a defrost demand. If a defrost
demand exists, a defrost cycle will be initiated at the end of the selected
time interval. A defrost demand exists when the coil temperature is at or
below 32
_
F / 0
_
C for 4 minutes during the interval.
The defrost cycle is terminated when the coil temperature reaches 65
_
F
or 10 minutes has passed.
On 286B models, defrost will occur in low- or high-stage as demanded
by the thermostat or User Interface regardless of OAT
On 289B models, when OAT is >25
_
F / -3.9
_
C, defrost will occur in
low- or high-stage as demanded by the thermostat or User Interface.
On 289B models, if OAT is
≤
25
_
F /-3.9
_
C, defrost will occur in
high-stage only, regardless of thermostat or User Interface demand, and
will terminate at 50
_
F (10
_
C) coil temperature with a minimum of 2.5
minutes in defrost.
If the coil temperature does not reach 32
_
F / 0
_
C within the interval, the
interval timer will be reset and start over.
• Upon initial power up the first defrost interval is defaulted to 30
minutes. Remaining intervals are at selected times.
• Defrost is only allowed to occur below 50
_
F / 10
_
C outdoor
ambient temperature.
The outdoor fan output (ODF) will remain off for 20 seconds after
termination. This delay will allow time for the system to capture the
heat from the outdoor coil and reduce the “steam cloud” effect that may
occur on transition from defrost to the heating cycle. The outdoor fan
output OFF delay of 20 seconds may be defeated to enable the fan to
energize immediately at the time of termination and 12 seconds prior to
the reversing valve de-energizing, through the User Interface setup
screen available with SYSTXCCIT01-B UI, or forced defrost pins as
follows:
• The ODF fan delay defeat can be toggled by shorting the forced
defrost pins for >15 seconds while in the standby mode (status LED
on solid). The LED will start to flash when the toggle has taken
place.
• Status code 4 shows the fan delay defeat is active (no delay)
• Status code 3 shows that it is not active (20 second delay)
The code will continue to be displayed until after the short is removed.
Once the short is removed, there is a 5 second wait before the code is
cancelled. The code that is flashing will finish before going back to sold
LED. The control is shipped with the ODF fan delay defeat NOT active.
the change in status is remembered until toggled to a new status. A
power down / power up sequence will not reset the status. It may be
necessary to do the toggle twice to cycle to the desired state of defeat.
