57
7. Verify adequate charge by continuing to run at full load with
42 to 46 F (5.6 to 7.8 C) cooler leaving fluid temperature.
Check that the refrigerant is not flashing in the liquid-line
sight glass. The EXV Percent Open should be between 40
and 60%. The cooler level indicator should be in the range
of 1.5 to 2.2.
Indication of low charge on a 30HXA, GX systems:
1. Make sure that the circuit is running at a full load condition
and all condenser fans are energized and running at full
speed. To check whether circuit A is fully loaded, enter
on the HSIO keypad. The display will read “CIR-
CUIT A ANALOG VALUES.” Using the down arrow key
on the keypad, scroll down once to “Total Capacity.” If this
value is 100%, the circuit is at full load. To check circuit B,
follow the same procedure, but enter
on the
keypad.
2. It may be necessary to use the Manual Control feature to
force the circuit into a full-load condition. If this is the case,
see the instructions for using the Manual Control feature in
Table 22 on page 33 of this manual.
3. With the circuit running at full-load, verify that the cooler
leaving fluid temperature is in the range of 38 to 48 F (5.6 to
7.8 C).
4. For 30HXA chillers, raise the compressor discharge to
approximately 125 F (51.7 C) saturated discharge tempera-
ture (185 psig [1276 kPa]). For 30GX chillers, raise the
compressor discharge to approximately 130 F (54.4 C) satu-
rated discharge temperature (198 psig [1366 kPa]). Measure
the liquid temperature entering the expansion device for
30HXA units. For 30GX units, measure the liquid tempera-
ture after the tee where all liquid lines have joined. The liq-
uid temperature should be approximately 107 F (41.7 C) for
optimum charge. If the temperature is greater than 107 F
(41.7 C) and the sight glass is flashing, the circuit is under-
charged.
5. Add 5 lb (2.3 kg) of liquid charge into the cooler using the
1
/
4
-in. Schrader-type fitting located on the tube entering the
bottom of the cooler. This fitting is located between the
Electronic Expansion Valve (EXV) (30HXA076-146 units,
30GX080-090 units), or the economizer (30HXA161-271
units, 30GX105-350 units) and the cooler.
6. Allow the system to stabilize and then recheck the liquid
temperature. Repeat Step 5 as needed allowing the system to
stabilize between each charge addition. Slowly add charge
as the sight glass begins to clear to avoid overcharging.
Oil Charging/Low Oil Recharging
Addition of oil charge to 30HX,GX systems:
1. If the 30HX,GX unit shuts off repeatedly on Low Oil Level
(Alert number 71 or 72), this may be an indication of inad-
equate oil charge. It could also mean simply that oil is in
the process of being reclaimed from the low-side of the
system.
2. Begin by running the unit at full load for 1
1
/
2
hours. Use the
Manual Control feature of the software if the unit does not
normally run at full load.
3. After running the unit for 1
1
/
2
hours, allow the unit to
restart and run normally. If the Low Oil Level alarms per-
sist, continue following this procedure.
4. Close the liquid line service valve, and place a pressure
gage on top of the cooler. Enable the manual control fea-
ture using the HSIO keypad, and turn the LOR switch to
local. Start the desired compressor by pressing
on the keypad, at the appropriate line on the display.
5. Before starting the compressor, the unit will go through its
normal pre-lube pump routine. If there is an insufficient
level of oil in the oil separator, the compressor will not
start, and a pre-start oil pressure alarm will be posted. Skip
to Step 8.
6. If the compressor starts successfully, observe the cooler
pressure gage. When this gage reads approximately
10 psig, press
on the HSIO keypad, and move the
LOR switch to the off position.
7. Open the liquid line service valve and allow the unit to
restart and run normally. If the Low Oil Level alarms per-
sist, continue following this procedure.
8. If none of the previous steps were successful, the unit is
low on oil charge. Add oil to the oil separator using the
1
/
4
-in. Schrader-type fitting on the discharge line entering
the top of the oil separator (30HX units) or through the
Schrader fitting on the top of the oil separator (30GX
units).
9. Make sure that the unit is not running when adding oil, as
this will make the oil charging process easier. Because the
system is under pressure even when the unit is not running,
it will be necessary to use a suitable pump (hand pump or
electric pump) to add oil to the system.
10. Using a suitable pump, add
1
/
2
gal. (1.89 L) of Castrol Ice-
matic
®
SW-220 Polyolester oil (Carrier Specification
number is PP47-32; absolutely no substitutes are
approved) to the system. Make sure that the oil level safety
switch is NOT jumpered, and allow the unit to restart and
run normally. Do not exceed maximum oil change. See
Table 41.
11. If low oil level problems persist, add another 1.89 L
(
1
/
2
gal.) of oil. Continue adding oil in 1.89 L (
1
/
2
gal.)
increments until the problem is resolved. If it is necessary
to add more than 5.75 L (1.5 gallons) of oil to the system,
contact your Carrier distributor service department.
Table 41 — Maximum Oil Charges
Do not add oil at any other location as improper unit opera-
tion may result.
UNIT
SIZE
CIRCUIT A
(gal)
CIRCUIT A
(L)
CIRCUIT B
(gal)
CIRCUIT B
(L)
30GX080-176
5.0
18.9
5.0
18.9
30GX205-265
7.0
26.5
5.0
18.9
30GX281-350
7.0
26.5
7.0
26.5
30HXA076-186
5.0
18.9
5.0
18.9
30HXC076-186
4.5
17.0
4.5
17.0
30HXA,C206-271
7.5
28.4
5.0
18.9
ENTER
ENTER
