56
Condenser Fans (30GX Only) —
Each fan is sup-
ported by a formed wire mount bolted to a fan deck and cov-
ered with a wire guard. The exposed end of the fan motor shaft
is protected from weather by grease. If the fan motor must be
removed for service or replacement, be sure to regrease fan
shaft and reinstall fan cover, retaining clips, and fan guard. For
proper performance, the fans should be positioned as shown in
Fig. 16 or 17. Tighten setscrews to 14
±
1 ft-lb (18
±
1.3 N-m).
Check for proper rotation of the fan(s) once reinstalled
(clockwise for high static and counterclockwise for standard
viewed from above). If necessary to reverse, switch leads at
contactor(s) in control box.
Refrigerant Charging/Adding Charge
Indication of low charge on a 30HXC system:
NOTE: To check for low refrigerant charge on a 30HXC, sev-
eral factors must be considered. A flashing liquid-line sight
glass is not necessarily an indication of inadequate charge.
There are many system conditions where a flashing sight glass
occurs under normal operation. The 30HXC metering device is
designed to work properly under these conditions.
1. Make sure that the circuit is running at a full-load condition.
To check whether circuit A is fully loaded, enter
on the HSIO keypad. The display will read “CIRCUIT 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 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 46 F (3.3 to
7.8 C). Check pressure drop across liquid line strainer.
Strainer is cleanable if necessary.
4. At this condition, observe the refrigerant in the liquid line
sight glass. If there is a clear sight glass, and no signs of
flashing, then the circuit is adequately charged. Skip the
remaining steps.
5. If the refrigerant appears to be flashing, the circuit is proba-
bly low on charge. Verify this by checking the EXV Percent
Open. This information can be accessed by entering
on the HSIO keypad for Circuit A, or
for
Circuit B. Scroll down using the down arrow key on the
keypad, until EXV Percent Open is displayed.
6. If the EXV Percent Open is greater than 60%, and the
liquid-line sight glass is flashing, then the circuit is low on
charge. Follow the procedure for adding charge for 30HXC
units.
To add charge to the 30HXC systems:
1. Make sure that the unit is running at full load, and that the
cooler leaving fluid temperature is in the range of 42 to 46 F
(5.6 to 7.8 C).
2. At these operating conditions, check the liquid line sight
glass. If there is a clear sight glass, then the unit has suffi-
cient charge. If the sight glass is flashing, then check the
EXV Percent Open. If this is greater than 60%, then begin
adding charge.
NOTE: A flashing liquid line sight glass at operating condi-
tions other than those mentioned above is not necessarily an
indication of low refrigerant charge.
3. 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) (size 076-146 units), or
the economizer (size 161-271 units) and the cooler.
4. Observe the EXV Percent Open value. The EXV should
begin closing as charge is being added. Allow the unit to
stabilize. If the EXV Percent Open remains above 60%,
and the sight glass continues flashing, add an additional 5 lb
(2.3 kg) of liquid charge.
5. Allow the unit to stabilize, and again check the EXV Percent
Open. Continue adding 5 lb (2.3 kg) at a time of liquid
refrigerant charge, and allow the unit to stabilize before
checking the EXV position.
6. When the EXV Percent Open is in the range of 40 to 60%,
check the liquid line sight glass. Slowly add enough addi-
tional liquid charge to ensure a clear sight glass. This should
be done slowly to avoid overcharging the unit.
IMPORTANT: These units are designed for use with
R-134a only. DO NOT USE ANY OTHER REFRIG-
ERANT in these units without first consulting your Car-
rier representative.
When adding or removing charge, circulate water through
the condenser (30HXC) and cooler at all times to prevent
freezing. Freezing damage is considered abuse and may
void the Carrier warranty.
DO NOT OVERCHARGE system. Overcharging results
in higher discharge pressure with higher cooling fluid con-
sumption, possible compressor damage and higher power
consumption.
PLASTIC FAN
PROPELLER
CLEARANCE OF 0.25 INCHES
(6.4 MM) FOR STANDARD
CONDENSER FANS
FAN DECK
SURFACE
FAN ORIFICE
POSITION TOP OF HIGH STATIC FAN PROPELLER HUB
2.15 INCHES (54.6 mm) ABOVE FAN DECK SURFACE
FAN DECK
SURFACE
STATIC FAN
PROPELLER
FAN HUB
2.15 IN.
MOTOR
SHAFT
Fig. 16 — Condenser Fan Position (Standard Fan)
Fig. 17 — Condenser Fan Position
(High Static Fan)