Nortek Q104SD Series, User Manual

Page: 12 / 20

12
IMPORTANT NOTES:
• To achieve rated capacity and efficiency the compressor
must be exposed to refrigerant for at least 24 hours prior
to running and then must be run for a minimum of 12
hours.
• The refrigerant cooling charging charts are applicable
to units at rated factory airflows for the indoor coil. See
Figure 10 , Figure 11 (page 16) , Figure 12 , Figure 13
(page 17) , Figure 14 , Figure 15 (page 18) .
Charging an R-410A Unit in AC Mode
(With Outdoor Temperatures Above 60° F)
1. With the system operating at steady-state, measure the
liquid refrigerant pressure in psig at the service valve.
Measure the liquid refrigerant temperature in Fahrenheit
on the liquid line before TXV at indoor coil.
2. For the temperature measured, determine the required
liquid refrigerant pressure from the appropriate charging
charts in Figure 10 , Figure 11 (page 16) , Figure 12 ,
Figure 13 (page 17) , Figure 14 , Figure 15 (page
18) .
3. If the pressure measured in step 1 is greater than the
required liquid refrigerant pressure determined in step
4, then there is too much charge in the system. Remove
refrigerant and repeat steps 1 through 3 until the system
is correctly charged.
4. If the pressure measured in step 1 is less than the
required liquid refrigerant pressure determined in step
4, then there is too little charge in the system. Add
refrigerant and repeat steps 1 through 3 until the system
is correctly charged.
Charging an R-410A Unit in Heating Mode
Use the steps below for proper charging of unit in heat
mode:
1. Evacuate the refrigerant system.
2. Weigh in the proper charge as shown on the unit rating
plate (during heating mode operation).
3. Verify the unit is operating properly according to the
System Heating-Heat Pump Mode section on page 11.
Verification of Charge in Refrigerant Heating Mode
• Block off half of the outdoor fan discharge grille area
as shown.
• With the unit in COOLING MODE, use the appropriate
charging chart curves shown in Tables 10-15 as a guide
to ensure proper operation of your system.
• For units with a TXV, the refrigerant system should be
evacuated and the proper charge weighed in as shown
on the unit rating plate.
• Return to the system when the outdoor temperature is
60 degrees F or higher and follow the steps defined in
Charging an R410A Unit in AC Mode.
NOTE: Unit charge MUST be verified in cooling season.
HEAT PUMP MAINTENANCE
WARNING:
To prevent electrical shock, personal injury, or
death, disconnect all electrical power to the unit
before performing any maintenance or service.
Unit may have more than one electrical supply.
CAUTION:
Use care when servicing the heat pump or
removing components. Personal injury can
result from sharp edges present in equipment
constructed with sheet metal
Proper maintenance is important to achieve optimum
performance from the heat pump. 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.
RECOMMENDED EXTERNAL FILTER SIZES
Nominal
Cooling
(Tonnage)
Filter Size
(in. x in.)
Approximate
Air Flow Range
(CFM)
Approximate Filter
Area (sq. in.)*
2.0 20 x 25 600-900 480
2.5 25 x 25 750-1125 600
3.0 25 x 25 900-1350 600
3.5 20 x 25 (2 required) 1050-1575 960
4.0 20 x 25 (2 required) 1200-1700 960
5.0 20 x 25 (2 required) 1500-2000 960
*Based on velocity of 300ft/min for disposable filters.
Table 1. Recommended External Filter Sizes
• The motors for the circulating air blower and the outdoor
fan are pre-lubricated at the factory. No further oiling is
required for the life of this product.
Minimum Required
Clearances to Obstructions
0"
36"
36"
36"
TOP OF UNIT
TO
BE
UNOBSTR
UCTED
36” For Coil Only