7
air conditioner maintenance
Warning:
to prevent electrical shock, personal injury, or
death, disconnect all electrical power to the unit
before performing any maintenance or service.
the unit may have more than one electrical supply.
Proper maintenance is important to achieve optimum
performance from the air conditioner. The ability to properly
perform maintenance on this equipment requires certain
mechanical skills and tools. If you do not possess these
skills, contact your dealer for maintenance. Consult your
local dealer about the availability of maintenance contracts.
Routine maintenance should include the following:
• Inspect and clean or replace air filters at the beginning
of each heating and cooling season, or more frequently
if required.
• Inspect the condensate drain and outdoor coil at the
beginning of each cooling season. Remove any debris.
Clean the outdoor coil and louvers as necessary using a
mild detergent and water. Rinse thoroughly with water.
• Inspect the electrical connections for tightness at the
beginning of each heating and cooling season. Service
as necessary.
caUtion:
the unit should never be operated without a
filter in the return air system. replace disposable
filters with the same type and size.
• Do not attempt to add additional oil to motors un
-
equipped with oil tubes. The compressor is hermetically
sealed at the factory and does not require lubrication.
reFrigerant charging
Warning:
S4BF Split System air conditioners are shipped
charged with r410a refrigerant and ready
for installation. if repairs make it necessary
for evacuation and charging, it should only
be attempted by qualified trained personnel
thoroughly familiar with this equipment. Under
no circumstances should the owner attempt to
install and/or service this equipment. Failure to
comply with this warning could result in property
damage, personal injury, or death.
After refrigerant line connections are completed, it is
required that you leak check and evacuate the indoor
section and all line connections (using proper methods)
before finalizing the full system refrigerant charge.
• Refrigerant charging charts are applicable only to
matched assemblies of NORDYNE equipment and
listed airflows for the indoor coil. Refer to
for correct system charging.
• S4BF outdoor units with non-AHRI listed indoor coils
are not recommended. Deviations from rated airflows or
non-listed combinations may require modification to the
expansion device and refrigerant charging procedures
for proper and efficient system operation.
• The refrigerant charge can be checked and adjusted
through the service ports provided external to the
outdoor unit. Use only gage line sets which have a
“Schrader” depression device present to actuate the
valve.
• A high-pressure switch is factory-installed and located
in the liquid line internal to the outdoor unit. The switch
is designed to protect the system when very high
pressures occur during abnormal conditions. Under
normal conditions, the switch is closed. If the liquid
pressure rises above 575 psig, then the switch will open
and de-energize the outdoor unit. The switch will close
again once the liquid pressure decreases to 460 psig.
Please note that the switch interrupts the thermostat
inputs to the unit. Thus, when the switch opens and
then closes, there may be a 5 minute short cycling
delay before the outdoor unit will energize.
•
on
select models a low-pressure switch is factory-
installed and located in the suction line internal to
the outdoor unit. The switch is designed to protect
the compressor from a loss of charge. Under normal
conditions, the switch is closed. If the suction pressure
falls below 5 psig, then the switch will open and de-
energize the outdoor unit. The switch will close again
once the suction pressure increases above 20 psig.
Please note that the switch interrupts the thermostat
inputs to the unit. When the switch opens and then
closes, there will be a 5 minute short cycling delay
before the outdoor unit will energize.
charging the Unit in ac mode
(With outdoor temperatures above 65° F)
1. With the system operating at steady-state, measure the
liquid refrigerant pressure (in psig) at the outdoor unit
service valve.
2. Measure the liquid refrigerant temperature (in Fahrenheit)
at the service valve.
3. Determine the required liquid refrigerant pressure from
the appropriate charging chart. See
• If the pressure measured in Step 1 is greater than
the required liquid refrigerant pressure determined in
Step 3, then there is too much charge in the system.
Remove refrigerant and repeat Steps 1 through 3 until
the system is correctly charged.
• If the pressure measured in Step 1 is less than the
required liquid refrigerant pressure determined in Step
3, there is too little charge in the system. Add refrigerant
and repeat Steps 1 through 3 until the system is correctly
charged.
