13
Table 6 – Chiller and Condenser Refrigerant Charge
Circuit
Capacity
(tons)
Total Combined Chiller and Condenser
Summertime Refrigerant Charge (Lbs. of R410A)
Single-Circuit Chiller
(pounds per circuit)
Dual-Circuit Chiller
(pounds per circuit)
10
15.3
17.3
15
22.2
24.7
20
30.2
30.2
25
37.2
37.2
30
44.3
43.8
40
59.4
59.4
50
79.6
79.6
60
109.0
108.5
80
136.1
136.1
100
119.3
125.2
120
139.9
151.2
Table 7 - Field Piping R-410A Refrigerant Charges
Line Size OD
(inches)
Discharge Line
(Lbs./100’ run)
Liquid Line
(Lbs./100’ run)
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
Check oil level after the chiller has run for 15
minutes.
Installation - Electrical
All wiring must comply with local codes and the
National Electric Code. Minimum circuit amps (MCA)
and other unit electrical data are on the unit
nameplate. A unit specific electrical schematic ships
with the unit. Measure each leg of the main power
supply voltage at the main power source. Voltage
must be within the voltage utilization range given on
the drawings included with the unit. If the measured
voltage on any leg is not within the specified range,
notify the supplier and correct before operating the
unit. Voltage imbalance must not exceed two
percent. Excessive voltage imbalance between the
phases of a three-phase system can cause motors to
overheat and eventually fail. Voltage imbalance is
determined using the following calculations.
% Imbalance = (Vavg – Vx) x 100 / Vavg
Vavg = (V1 + V2 + V3) / 3
Vx = phase with greatest difference from Vavg
For example, if the three measured voltages were
442, 460, and 454 volts, the average would be:
(442 + 460 + 454) / 3 = 452
The percentage of imbalance is then:
(452 – 442) x 100 / 452 = 2.2 %
This exceeds the maximum allowable of 2%.
There is a terminal block for main power connection
to the main power source. The main power source
should be connected to the terminal block through
an appropriate disconnect switch. There is a separate
lug in the main control panel for grounding the unit.
Check the electrical phase sequence at installation
and prior to start-up. Operation of the compressor
with incorrect electrical phase sequencing will result
in mechanical damage to the compressors. Check
the phasing with a phase sequence meter prior to
applying power. The proper sequence should read
“ABC” on the meter. If the meter reads “CBA”, open
the main power disconnect and switch two line leads
on the line power terminal blocks (or the unit
mounted disconnect). Do not interchange any load
leads that are from the unit contactors or the motor
terminals.
