Refrigerant Lines; System Evacuation And Charging - Carrier 24AHA4 Service Manual

REFRIGERANT LINES

General refrigerant line sizing:
1 The outdoor units are shipped with a full charge of R410A
refrigerant. All charges, line sizing, and capacities are based
on runs of 25 ft (7.6 m). For runs over 25 ft (7.6 m), refer to
the Residential Long Line Guide.
2 Minimum refrigerant line length between the indoor and
outdoor units is 10 ft. (3 m).
3 Refrigerant lines should not be buried in the ground. If it is
necessary to bury the lines, not more than 36- -in (914 mm)
should be buried. Provide a minimum 6- -in (152 mm) vertical
rise to the service valves to prevent refrigerant migration.
4 Both lines must be insulated. Use a minimum of 1/2- -in.
(12.7 mm) thick insulation. Closed- -cell insulation is
recommended in all long- -line applications.
5 Special consideration
interconnecting tubing from the building structure. Isolate the
tubing so that vibration or noise does not transmit into the
structure.
IMPORTANT: Both refrigerant lines must be insulated
separately.
S The following maximum lengths are allowed:
Table 12 – Maximum Refrigerant Line Lengths
Unit Max Line Max Elevation
Size Length* ft(m) (ID over OD) ft( m)
18K 250 (76.2)
24K 250 (76.2)
30K 250 (76.2)
36K 250 (76.2)
Note: For lengths greater than 25 ft. (7.6 m), refer to the Residential
Long Line Guide.
*Maximum actual length not to exceed 200 ft. (61 m). Total equivalent
length accounts for losses due to elbows or fitting. See the Long Line
Guideline for details.
S The following are the piping sizes.
Table 13 – Pipe Sizes
Pipe Sizes (in)
Unit Size Mix Phase - - in
18K
24K
30K
36K
Note: Both lines need to be insulated using at least 1/2 inch closed
foam insulation.
Refrigerant Charge
Table 14 – Charge Requirements
System Nominal
Outdoor Unit
Capacity
Type
018 24AHA418A003 124ANS018000
Cooling
022 24AHA424A003 124ANS024000
028 24AHA430A003 124ANS030000
Only
032 24AHA436A003/5/6 124ANS036000
Heat
024 25HHA424A003 224ANS024000
Pump 028 25HHA430A003 224ANS030000
The above additional charge is required amount for line lengths up to
25 ft (7.6 m). For line lengths exceeding 25 ft. (7.6 m), additional
charge will be required. Refer to the Residential Long Line Guide.
Metering Device
The metering device(s) for these systems is a type B accurator. The
cooling accurator is installed with the indoor unit, while the
heating accurator is installed with the outdoor unit. One Accurator
is required for the cooling only system and two are required for the
heat pump systems. Refer to Table 15 for the accurator size.
Table 15 – Accurator Sizes
Cooling Only
System Size
40MKC**B
018 0.046"
022, 024 0.052"
028 0.059"
032 0.065"
should be given to isolating
Max Elevation
(OD over ID) ft (m)
65 (19.8) 200 (61)
65 (19.8) 200 (61)
65 (19.8) 200 (61)
65 (19.8) 200 (61)
Vapor - - in
3/8 5/8
3/8 3/4
3/8 3/4
3/8 7/8
Charge to
Sub- - cooling Delta
Indoor Unit
from Rating Plate
Value
40MKCB18B- - - - 3 12
40MKCB22B- - - - 3 12
40MKCB28B- - - - 3 12
40MKCB32B- - - - 3 8
40MKQB24B- - - - 3 14
40MKQB28B- - - - 3 11
Heat Pumps
40MKQ**B 25HHA4/224ANS
- - - -
0.052" 0.049"
0.057" 0.055"
- - - -
SYSTEM EVACUATION AND
CHARGING
CAUTION
!
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage or improper operation.
Never use the system compressor as a vacuum pump.
Refrigerant tubes and indoor coil should be evacuated using the
recommended deep vacuum method of 500 microns. The alternate
triple evacuation method may be used if the procedure outlined
below is followed. Always break a vacuum with dry nitrogen.
SYSTEM VACUUM AND CHARGE
Using Vacuum Pump
1 Completely tighten flare nuts A, B, C, D, connect manifold
gage charge hose to a charge port of the low side service
valve (see Fig. 16).
2 Connect charge hose to vacuum pump.
3 Fully open the low side of manifold gage (see Fig. 17).
4 Start the vacuum pump.
5 Evacuate using either deep vacuum or triple evacuation
method.
6 After evacuation is complete, fully close the low side of
manifold gage and stop operation of vacuum pump.
7 The factory charge contained in the outdoor unit is good for up
to 25 ft. (8 m) of line length. For refrigerant lines longer than
25 ft. (8 m), add charge, up to the maximum allowable length,
as specified in the residential Long Line Application Guide.
8 Disconnect charge hose from charge connection of the low
side service valve.
9 Fully open service valves B and A.
10 Securely tighten caps of service valves.
Refrigerant
Outdoor Unit
A
B
Service Valve
Fig. 16 – Service Valve
Manifold Gage
500 microns
Low side valve
Charge hose
Low side valve
Fig. 17 – Manifold
14
Indoor Unit
Low Side C
D
High Side
A07360
High side valve
Charge hose
Vacuum pump
A07361