11
Calculating Refrigerant and Oil Charge
To estimate the total amount of refrigerant required
to charge the system combine the charges from the
below two tables for the size system and line sizes
used..
Table 5 – Chiller & Condenser Refrigerant Charge
Circuit Capacity
(tons)
Chiller and Condenser Combined Summertime
Refrigerant Charge (lbs of R410A)
5 7.6
7.5 11.1
10 15.3
15 22.2
20 30.2
25 37.2
30 44.3
35 51.9
40 59.4
Table 6 - Field Piping R-410A Refrigerant Charges
Line Size OD
(inches)
Lbs of R410A per 100 Foot of Line Length
Discharge Line
Liquid Line
3/8 0.4
3.7
1/2 0.7
6.8
5/8 1.1
11
3/4 1.6 16.4
7/8 2.2 22.8
1 1/8
3.6
36.7
1 3/8
5.6
57.4
1 5/8
7.9
81.2
2 1/8
13.9
142.1
2 5/8
21.4
219.5
Oil Charge Determination
The chiller is factory charged with the amount of oil
required by the chiller only and not the total system.
The amount of oil required is dependent upon the
amount of refrigerant added to the system for the
field-installed piping. Use the following to determine
the amount of oil needed for the system.
Pints of Oil = Pounds of refrigerant in system / 100
Oil level should be checked after the chiller has run
for 15 minutes.
Setting Condenser Fan Controls
The remote condenser has a controller that cycles
the fans as needed to maintain the proper
refrigerant pressure. The settings change based on
the number of fans in the remote condenser. Refer
to Table 7 for the proper pressure settings.
Table 7 - Condenser Fan Pressure Settings (psig)
Stage
Number
Setting
Number of Fan Stages
1
2
3
4
Stage 1
Max
Speed 410 410 410 410
Min
Speed 320 320 320 320
Stage 2
Fan
On
400 400 370
Fan
Off 340 340 305
Stage 3
Fan On
435
385
Fan Off
375
325
Stage 4
Fan
On
400
Fan
Off
340
To change the settings open the remote condenser
control panel, remove the cover from the pressure
control module, and make sure everything is set as
shown below.
Figure 8 – Remote Condenser Fan Control Settings
