Nortek FT4BE-K - Refrigerant Charging; Charging Guidelines; Charging the Unit in AC Mode

9
• 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addadditionaloiltomotorsunequippedwithoil
tubes. The compressor is hermetically sealed at the
factory and does not require lubrication.
REFRIGERANT CHARGING
WARNING:
This split system heat pump is 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.
• Toachieveratedcapacityandefciency,thecompressor
must be exposed to refrigerant for at least 24 hours
prior to running and then the compressor must be run
for a minimum of 12 hours.
• Cooling mode charging charts are applicable only
to matched assemblies of this equipment and listed
airflows for the indoor coil. Outdoor units with non-
AHRI lsited indoor coils are not recommended and
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. Refer to Figures 5 - 11 (pages 10 -
13) and Tables 4 - 10 (pages 15 - 16) for correct system
charging.
• 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 common suction port for heating mode charging
is included and located on the compressor access
panel above the outdoor unit service valves.
• HeatModeVericationTables(Tables4-10,pages
14-16) are provided for quick reference when the unit
is in heating mode and for the inspection of the liquid
line pressures and temperatures.
• Ahigh-pressureswitchisfactory-installedandlocated
in the compressor discharge line internal to the
outdoor unit. The switch is designed to de-energize
the system when very high pressures occur during
abnormal conditions. Under normal conditions, the
switch is closed. If the discharge 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.
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 55° F
(for optimized sub-cooling of 10° F to 12° 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
Figures 5 - 11 (pages 10 - 13).
• 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.