Installation guide
INST ALLATION INSTRUCTIONS R- 410A Split System Air Conditioner
6 421 01 1702 05
Specifications subject to change without notice.
Airflow Setup with Non-Communicating Furnace or
Fan Coil
Two- stage compressor operation requires two different indoor
airflow settings for proper operation. This outdoor unit is designed
for use only with an indoor blower that can be configured for
separate low- stage and high- stage airflow (CFM) levels. Refer to
Product Specifications Sheets for recommended low- stage and
high- stage indoor airflow values.
Refer to indoor unit Installation Instructions to set the indoor
blower for the proper low- stage and high - stage airflow values.
NOT E : Op tim a l co m fo rt, efficie nc y, an d re lia b ility will o nly b e
achieved when the indoor airflow is properly set for both
low- stage and high- stage operation.
START- UP
CAUTION
!
UNIT OPERAT ION AND SAFETY HAZARD
Failure to follow this caution may result in minor personal
injury, equipment damage or improper operation.
To prevent compressor damage or personal injury,
observe the following:
S Do not overcharge system with refrigerant.
S Do not operate unit in a vacuum or at negative
pressure.
S Do not disable low pressure switch in scroll compressor
applications.
S Dome temperatures may be hot.
CAUTION
!
PERSONAL INJURY HAZARD
Failure to follow this caution may result in personal injury.
Wear safety glasses, protective clothing, and gloves
when handling refrigerant and observe the following:
S Front seating service valves are equipped with
Schrader valves.
CAUTION
!
ENVIRONMENTAL HAZARD
Failure to follow this caution may result in environmental
damage.
Federal regulations require that you do not vent refrigerant
to the atmosphere. Recover during system repair or final
unit disposal.
Follow these steps to properly start up the system:
1. After system is evacuated, fully open liquid and vapor
service valves.
2. Unit is shipped with valve stem(s) front seated (closed) and
caps installed.
Replace stem caps after system is opened to refrigerant
flow. Replace caps finger- tight and tighten with wrench an
additional 1/12 turn
3. Close electrical disconnects to energize system.
4. Set room thermostat at desired temperature. Be sure set
point is below indoor ambient temperature.
5. Set room thermostat to COOL and fan control to ON or
AUTO mode, as desired. Operate unit for 15 minutes.
Check system refrigerant charge.
Check Charge
Two- stage equipment must be charged in high stage compressor
operation only.
Factory charge amount and desired subcooling are shown on unit
rating plate. Charging method is shown on information plate
inside unit. To properly check or adjust charge, conditions must
be favorable for subcooling charging. Favorable conditions exist
when the outdoor temperature is between 70_F and 100_F
(21.11_C and 37.78_C), and the indoor temperature is between
70_F and 80_F (21.11_C and 26.67_C). Follow the procedure
below:
Unit is factory charged for 15ft (4.57 m) of lineset. Adjust charge
by adding or removing 0.6 oz/ft of 3/8 liquid line above or below
15ft (4.57 m) respectively.
For standard refrigerant line lengths (80 ft/24.38 m or less), allow
system to operate in cooling mode at least 15 minutes. When
operating with the Observer Wall Control in communicating mode,
make sure that indoor airflow is set to the final operating selection
(Eff 325, Eff 350, Comfort, Maximum) during charging. If
conditions are favorable, check system charge by subcooling
method. If any adjustment is necessary, adjust charge slowly and
allow system to operate for 15 minutes to stabilize before
declaring a properly charged system.
If the indoor temperature is above 80_F (26.67_C), and the
outdoor temperature is in the favorable range, adjust system
charge by weight based on line length and allow the indoor
temperature to drop to 80_F (26.67_C) before attempting to check
system charge by subcooling method as described above.
If the indoor temperature is below 70_F (21.11_C), or the outdoor
temperature is not in the favorable range, adjust charge for line
set length above or below 15ft (4.57 m) only. Charge level should
then be appropriate for the system to achieve rated capacity. The
charge level could then be checked at another time when the
both indoor and outdoor temperatures are in a more favorable
range.
NOTE: The Observer Wall Control has a s taging timer, to override
the staging timer for charging in high- stage create at least a 5
degree difference between room and set point temperatures and
hold the “Cool To” button for 10 seconds on the thermostat home
screen.
NOTE: If line length is beyond 80 ft (24.38 m) or greater than 20
ft (6.10 m) vertical separation, See LongLine Applications Guideline
for special charging requirements.
SYSTEM FUNCTIONS AND SEQUENCE OF
OPERATION
The *CA7 models utilize either an Observer Communicating Wall
Control or a 2-stage cooling thermostat. With a c all for first stage
cooling, the outdoor fan and low-stage compressor are energized.
If low-stage cannot satisfy cooling demand, high-stage is
energized by the second stage of the indoor thermostat. After
second stage is satisfied, the unit returns to low-stage operation
until first stage is satisfied or until second stage is required again.
When both first stage and second stage cooling are satisfied, the
compressor will shut off. When a 2-stage unit is operating at
low-stage, system vapor (suction) pressure will be higher than a
standard single-stage system or high-stage operation. When the
outdoor ambient is more than 100F (37.8C), the outdoor fan will
continue to run for one minute after compressor shuts off. This
reduces pressure differential for easier starting in the next cycle.