Specifications
Do not use high-pressure water or air to clean coils as
fin damage may result.
Condenser Fans (30GX Only) — Each fan is sup-
ported by a formed wire mount bolted to a fan deck and
covered 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
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
Carrier representative.
When adding or removing charge, circulate water through
the condenser (30HXC) and cooler at all times to pre-
vent freezing. Freezing damage is considered abuse and
may void the Carrier warranty.
DO NOT OVERCHARGE system. Overcharging re-
sults in higher discharge pressure with higher cooling
fluid consumption, possible compressor damage and higher
power consumption.
Indication of low charge on a 30HXC system:
NOTE: To check for low refrigerant charge on a 30HXC,
several factors must be considered. Aflashing 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 de-
vice is designed to work properly under these conditions.
1. Make sure that the circuit is running at a full-load con-
dition. To check whether circuit A is fully loaded, enter
on the HSIO keypad. The display will read
‘‘CIRCUIT A ANALOG VALUES.’’ Using the down ar-
row 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 19 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
and replace strainer 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 prob-
ably 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 suf-
ficient charge. If the sight glass is flashing, then check the
EXV Percent Open. If this is greater than 60%, then be-
gin adding charge.
NOTE: A flashing liquid line sight glass at operating con-
ditions other than those mentioned above is not neces-
sarily an indication of low refrigerant charge.
3. Add 5 lb of liquid charge into the cooler using the
1
⁄
4
-in.
Schrader-type fitting located on the tube entering the bot-
tom of the cooler. This fitting is located between the Elec-
tronic 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 of liquid charge.
5. Allow the unit to stabilize, and again check the EXV Per-
cent Open. Continue adding 5 lb at a time of liquid re-
frigerant charge, and allow the unit to stabilize before
checking the EXV position.
PLASTIC FAN
PROPELLER
CLEARANCE OF 0.25 INCHES
(6.4 MM) FOR STANDARD
CONDENSER FANS
FAN DECK
SURFACE
FAN ORIFICE
Fig. 16 — Condenser Fan Position (Standard Fan)
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. 17 — Condenser Fan Position (High Static Fan)
54