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C4H5S, H4H5S, T4H5S: Installation Instructions
Check Charge
Factory charge amount and desired subcooling are shown on unit rating
plate. Additional subcooling may be required to achieve optimal heating
performance based on the installed indoor unit. (see
Charging method is shown on information plate inside unit. For TXV,
use subcooling method. For piston, use superheat method. To properly
check or adjust charge, conditions must be favorable for subcooling or
superheat 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 (.018 kg/m) 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. If conditions are
favorable, check system charge by super heat method for fixed metering
device and subcooling method for TXV. If any adjustment is necessary,
adjust charge slowly and allow system to operate for 15 minutes to
stabilize before declaring a properly charged system. Refer to
for additional subcooling required.
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.
If line length is beyond 80 ft (24.38 m) or greater than 20 ft (6.10 m)
vertical separation, See Residential Piping and Long Line Guideline for
special charging requirements.
Units with Cooling Mode TXV
Units installed with cooling mode TXV require charging by the
subcooling method.
1. Operate unit a minimum of 15 minutes before checking charge.
2. Measure liquid service valve pressure by attaching an accurate gage
to service port.
3. Measure liquid line temperature by attaching an accurate thermistor
type or electronic thermometer to liquid line near outdoor coil.
4. Refer to unit rating plate for required subcooling temperature.
5. Refer to
Table
5. Find the point where required subcooling
temperature intersects measured liquid service valve pressure.
6. To obtain required subcooling temperature at a specific liquid line
pressure, add refrigerant if liquid line temperature is higher than
indicated or reclaim refrigerant if temperature is lower. Allow a
tolerance of ?3°F.
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
Units with Indoor Pistons
Units installed with indoor pistons require charging by the superheat
method.
Table
4).
The following procedure is valid when indoor airflow is within 20
percent of its rated CFM.
1. Operate unit a minimum of 15 minutes before checking charge.
2. Measure suction pressure by attaching an accurate gage to suction
valve service port.
3. Measure suction temperature by attaching an accurate thermistor
type or electronic thermometer to suction line at service valve.
4. Measure outdoor air dry–bulb temperature with thermometer.
5. Measure indoor air (entering indoor coil) wet–bulb temperature
with a sling psychrometer.
6. Refer to
air wet–bulb temperature. At this intersection, note superheat.
Where a dash (––) appears on the table, do not attempt to charge
system under these conditions or refrigerant slugging may occur.
Charge must be weighted in, adding or removing 0.6 oz/ft of 3/8
liquid line above or below 15 ft (4.57 m) respectively.
Table 4
7. Refer to
suction pressure. At this intersection, note suction line temperature.
8. If unit has a higher suction line temperature than charted
temperature, add refrigerant until charted temperature is reached.
9. If unit has a lower suction line temperature than charted
temperature, reclaim refrigerant until charted temperature is
reached.
10. When adding refrigerant, charge in liquid form into suction service
port using a flow–restricting device.
11. If outdoor air temperature or pressure at suction valve changes,
charge to new suction line temperature indicated on chart.
12. Optimum performance will be achieved when the operating
charge produces 5° to 6°F suction superheat at suction service
valve with 82°F outdoor ambient and 80°F (26.7°C) dry bulb
67°F (19.4°C) wet bulb indoor temperature (DOE "B" test
conditions) at rated airflow.
Heating Check Chart Procedure
To check system operation during heating cycle, refer to the Heating
Check Chart on outdoor unit. This chart indicates whether a correct
relationship exists between system operating pressure and air
temperature entering indoor and outdoor units. If pressure and
temperature do not match on chart, system refrigerant charge may not be
correct. Do not use chart to adjust refrigerant charge.
12
Table
6. Find outdoor temperature and evaporator entering
Table
7. Find superheat temperature located in item 6 and
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