INSTALLATION INSTRUCTIONS
R
−
410A Split System Air Conditioner
421 01 5104 02
7
Specifications subject to change without notice.
Start
−
Up
CAUTION
!
UNIT OPERATION 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.
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Do not operate unit in a vacuum or at negative
pressure.
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Do not disable low pressure switch in scroll compressor
applications.
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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
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
“efficiency” 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
: If line length is beyond 80 ft (24.38 m) or greater than
20 ft (6.10 m) vertical separation, See Long Line Applications
Guideline for special charging requirements.
Major Components
Control Board
The AC control board controls the following functions:
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Compressor contactor operation
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Outdoor fan motor operation
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Compressor external protection
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Pressure switch monitoring
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Time Delays
Field Connections
When using communicating control, 4 field wires are required
to be connected to the factory wires already wired to the
DX+DX
−
C R terminal (see Fig. 10). Unit as provided by
manufacturer is set up for communicating control.
When used with a standard non
−
communicating thermostat,
it is recommended to use 3 thermostat control wires to be
connected to R, Y and C. When using 3 wires, all diagnostic
and time delay features are enabled (See Fig. 11).
Disconnect factory provided wires from DX+, DX
−
, C & R
terminals. Using factory provided wires, connect to R, C, and
Y on the control board for 3 wire thermostat control. Connect
field 24V wires to factory provided wires now connected to R,
C, and Y and cap both sides or remove unused factory
provided wires.
When only 2 thermostat control wires are available, units will
function, but some control features are lost. (See Fig. 12).
With only 2 wires connected, the circuit board will be
powered down whenever there is no call for cooling, and the
following will result:
S
Compressor time delay is reduced from 5 minutes to 10
seconds
S
When the thermostat is not calling for cooling, the amber
status light will be off, and no diagnostics codes will be
available
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All system counters will be reset on each new call for
cooling
