45
SERVICING
2. For best results, temporarily install a thermometer on the
liquid line at the liquid line service valve. Ensure the
thermometer makes adequate contact and is insulated for
best possible readings. Use liquid line temperature to
determine sub-cooling.
3. The system subcooling should fall in the range shown in
following table. If not in that range, adjust subcooling
according to the following procedure.
a. If subcooling is low, add charge to adjust the subcooling
as specified in the following table.
2 TON
10-12
°
F
3 TON
13-15
°
F
4 TON
8-10
°
F
5 TON
11-13
°
F
b. If subcooling is high, remove charge to lower the
subcooling to specified range.
NOTE
: Not more than 0.8 lb. (13 oz.) of refrigerant be added
to the system at a time to achieve the target
subcooling. It is recommended adding 4 oz.
refrigerant each time, then wait 20 minutes to
stabilize the system.
4. Disconnect manifold set. Installation is complete.
S-114
NON-CONDENSABLES
If non-condensables are suspected, shut down the system and
allow the pressures to equalize. Wait at least 15 minutes. Com-
pare the pressure to the temperature of the coldest coil since this
is where most of the refrigerant will be. If the pressure indicates
a higher temperature than that of the coil temperature, non-
condensables are present.
Non-condensables are removed from the system by first removing
the refrigerant charge, replacing and/or installing liquid line drier,
evacuating and recharging.
S-115
COMPRESSOR BURNOUT
When a compressor burns out, high temperature develops caus-
ing the refrigerant, oil and motor insulation to decompose form-
ing acids and sludge.
If a compressor is suspected of being burned-out, attach a refrig-
erant hose to the liquid line dill valve and properly remove and
dispose of the refrigerant.
NOTICE
Violation of EPA regulations may result in fines
or other penalties.
Now determine if a burn out has actually occurred. Confirm by
analyzing an oil sample using a Sporlan Acid Test Kit, AK-3 or its
equivalent.
Remove the compressor and obtain an oil sample from the suc-
tion stub. If the oil is not acidic, either a burnout has not occurred
or the burnout is so mild that a complete clean-up is not neces-
sary.
If acid level is unacceptable, the system must be cleaned by using
the clean-up drier method.
CAUTION
Do not allow the sludge or oil to contact the skin.
Severe burns may result.
NOTE:
The Flushing Method using R-11 refrigerant is no longer
approved by Daikin Brand Heating-Cooling.
S-120
REFRIGERANT PIPING
The piping of a refrigeration system is very important in relation
to system capacity, proper oil return to compressor, pumping rate
of compressor and cooling performance of the evaporator. A bi-
flow filter drier must be brazed on by the installer onsite. Ensure
the bi-flow filter drier pain finish is intact after brazing. If the
paint of the steel filter drier has been burned or chipped, repaint
or treat with a rust preventative. The recommended location of
the filter drier is before the electronic expansion valve at the
indoor unit. The liquid line must be insulated if more than 50 ft. of
liquid line will pass through an area that may reach temperatures
of 30
°
F of higher than ambient in cooling mode and/or if the
temperature inside the conditioned space may reach a tempera-
ture lower than ambient in heating mode.
FVC50K oils maintain a consistent viscosity over a large tempera-
ture range which aids in the oil return to the compressor; how-
ever, there will be some installations which require oil return
traps. These installations should be avoided whenever possible,
as adding oil traps to the refrigerant lines also increases the
opportunity for debris and moisture to be introduced into the
system.
Avoid long running traps in horizontal suction line.
