17
charging: weigh-In Method
weigh-In Method can be used for the Initial installation, or anytime a system charge is being
replaced. weigh-In Method can also be used when power is not available to the equipment
site or operating conditions (indoor/Outdoor temperatures) are not In range to verify with
the subcooling charging method.
Note: The only mode aperoved for setting validating system charge Is using Charging
Mode-cooling. ChargIng Mode-cooling is a variable speed test mode found in the 950
comfort control Technician Menu. Outdoor Temperature must be between 55
O
F and
120
O
F with Indoor Temperature kept between 70
O
F and 80
O
F.
Table 17. Heat Pumps
A C
D
Model
charge
adder for
Indoor Coil
charge
multiplier for
interconnecting
refrigerant tube
length
024
7 lb.
6 oz.
6 oz.
0.6 oz/ft
036
8 Ib.
3 oz.
8 oz.
0.6 oz/ft
037
9 lb.
8 oz.
12 oz.
0.6 oz/ft
048
9 lb. 13 oz.
13 oz.
0.6 oz/ft
049
10 lb. 12 oz.
15 oz.
0.6 oz/ft
060
11 lb. 14 oz. 1 lb., 2 oz.
0.6 oz/ft
Factory
Charge
B
Table 18. Air Conditioners
A C
D
Model
charge
adder for
Indoor Coil
charge
multiplier for
interconnecting
refrigerant tube
length
024
7 lb.
6 oz.
6 oz.
0.6 oz/ft
036
7 Ib.
14 oz.
7 oz.
0.6 oz/ft
048
11 lb. 1 oz.
1 lb., 0 oz.
0.6 oz/ft
060 11
lb.
14
oz.
0.6
oz/ft
Factory
Charge
B
Table 19. New Installations — calculating charge using the weigh-In method
1. Measure in feet the distance between the
outdoor unit and the indoor unit and record on Line
1. Include the entire length of the line from the
servIce valve to the IDU.
2. Enter the charge multiplier from column D.
3. Muitply the total length of refrigerant tubing (Line
1) tImes the value on step 2. Record the result on
Line 3 of the worksheet.
4. Locate the outdoor equipment size in column A.
Record the value shown In column c of Table 16 for
Heat Pumps or Table 17 for Air conditioners.
5. Add the values from step 3 and step 4 and
record the resulting value. This Is the amount of
refrigerant to weigh-in prior to opening the service
valves.
New Installation weigh-In Method woriksheeto
1. Line Length (ft)
2. value from Column D x
3. Step1 x Step2
=
4. charge Adder (column C) +
5. Refrlgerant(Steps 3+4) =
Table 20. Sealed-System Repairs — calculating charge using the weigh-In method.
1. Meisure in feet the distance between the
outdoor unit and the indoor unit and record on
Line 1 Include the entire length of the line from the
service valve to the IDU.
2. Enter the charge multiplIer from cotumn D.
3. MultIply the total length of refhgerant tubing
(Line 1) times the value on Line 2. Record the
result on Line 3 of the worksheet.
4. Locate the outdoor equipment size in column A.
Record the value shown in column C of Table 16
for Heat Pumps or Table 17 for Air conditioners.
5. Record the value in column B to Line 5 of the
worksheet.
6. Add the values from step 3, step 4, and step 5
and record the resulting value on Line 6. ThIs is
the amount of refrigerant to weigh-in.
New Installation weigh-In Method worksheet
1. Line Length (ft)
2. value from ColumnD x
3. Step 1 x step 2
=
4. charge Adder (column C) +
5. Factory charge (column B) +
6. RefrIgerant (steps 3+4+5) =
1 lb., 0 oz.
