Trane R Series Installation Operation & Maintenance page 67

Table 15 – Charge-Holding Capability on The High Side
Nominal Circuit
Capacity
(tons)
60
70
85
100
140
170
200
*Circuit charge varies slightly with efficiency and unit configuration.
As can be seen in Table 15, when the charge is isolated on the high side, the oil separators will be flooded with
refrigerant. This is because there is not enough room in the condenser to contain all the charge. For this reason,
when getting the unit back to running condition, care must be taken to drive the refrigerant out of the oil separator
using the oil separator heaters.
RLC-SVX02G-E4
Maintenance Procedures
Normal Circuit
*Condenser Charge-Holding
Charge
Capacity at 60% full, 35°C ambient
(kg)
74.8
74.8
79.4
97.5
102.1
165.6
188.2
Returning the unit to running
condition:
1. Open all the valves.
2. Manually open EXV for
15 minutes to allow the
refrigerant to drain to the
evaporator by gravity.
3. Let the unit sit with heaters on to
drive refrigerant out of the oil and
warm up the compressor
bearings. Depending upon
ambient conditions, this may take
up to 24 hours.
4. After the oil level has returned to
normal, the unit can be put back
into operation.
Low-side charge-isolation
procedure:
(only possible with optional suction
isolating valves)
After normal shutdown, most of the
charge resides in the evaporator.
Running cold water through the
evaporator may also drive much of
the refrigerant to the evaporator.
1. Make sure the circuit is off.
2. Close the suction-line isolation
valve.
3. Close the oil return-line service
valve.
4. Close the liquid line service valve.
5. Manually open the EXV.
6. Use a liquid pump or vacuum
pump to move refrigerant from
the condenser to the evaporator.
The liquid pump will only be
(kg)
53.6
53.6
60.9
74.3
85.2
92.3
127.9
Charge in Oil
Oil Separator
Separator
(liters)
21.3 97.70%
21.3 97.70%
18.5 86.00%
23.3 56.00%
16.8
73.3
60.3 86.10%
effective if there is a lot of charge
in the condenser. It may be
connected to the condenser drain
port on the liquid-line isolation
valve.
Note: if a pump is to be used,
connect it before closing this valve.
This port is only isolated when the
valve is backseated.
If a vacuum pump is used, then
connect it to the discharge-line
service valve near the oil separator.
A vacuum pump will be required for
part of the procedure.
The evaporator is large enough to
hold all the charge, for any unit,
below the centerline of the shell.
Therefore, no special precautions
are required to restart the unit after
isolating the charge in the
evaporator.
%
Level
41%
100%
67