Crankcase Heaters; Actual Start-Up; Check Refrigerant Charge; Charge Adjustment For Brine Operation - Carrier AquaSnap 30RAP011-060 Controls, Start-Up, Operation, Service, And Troubleshooting

Crankcase Heaters

Unit sizes 070-150 are equipped with crankcase heaters. Unit sizes
010-060 require field-installed crankcase heater(s) if remote cool-
er accessory is utilized. Compressor crankcase heaters, if
equipped, must be on for 24 hours before start-up. To energize the
crankcase heaters, close the field disconnect and turn on the fan
circuit breakers. Leave the compressor circuit breakers off/open.
The crankcase heaters are now energized.

Actual Start-Up

Actual start-up should be done only under supervision of a quali-
fied refrigeration mechanic.
1. Be sure all service valves are open.
2. Using the scrolling marquee display, set leaving-fluid set
point (Set Points  COOL  CSP.1). No cooling range
adjustment is necessary.
3. Start chilled fluid pump (if not configured for cooler pump
control).
4. Turn Enable/Off/Remote Control switch to ENABLE
position.
5. Allow unit to operate and confirm that everything is func-
tioning properly. Check to see that leaving fluid tempera-
ture agrees with leaving set point (Set Points  COOL
 CSP.1) or (Set Points  COOL  CSP.2), or if reset is
used, with the control point (Run Status  VIEW
 CTPT).
6. Check the cooler leaving chilled water temperature to see
that it remains well above 32°F (0°C), or the brine freezing
point if the unit is a medium temperature brine unit.
7. Recheck compressor oil level (see Oil Charge section).

Check Refrigerant Charge

All 30RAP units are shipped with a complete operating charge of
R-410A and should be under sufficient pressure to conduct a leak
test after installation. If there is no system pressure, admit nitrogen
until a pressure is observed and then proceed to test for leaks. Af-
ter leaks are repaired, the system must be dehydrated.
All refrigerant charging should be done through the
er connection on the liquid line. Do NOT add refrigerant charge
through the low-pressure side of the system. If complete charging
is required, weigh in the appropriate charge for the circuit as
shown on the unit nameplate. If partial charging is required, oper-
ate circuit at full load and use an accurate temperature sensor on
the liquid line as it enters the filter drier. Use the Temperatures
mode on the scrolling marquee display to show the circuit saturat-
ed condensing temperature (Temperatures  CIR.A  SCT.A) or
(Temperatures  CIR.B  SCT.B). Charging is most accurate at
saturated discharge temperatures of 120 to 125°F (49 to 52°C).
Block condenser airflow as required to reach this temperature
range. Add refrigerant until the system subcooling (SCT.A or
SCT.B minus liquid line temperature entering EXV) is
30RAP UNIT SIZE
LEAVING BRINE TEMPERATURE
44F-35F
34F-15F
/ in. Schrad-
1
4
Table 28 — Charge Adjustment for Brine Operation
CHARGE TO BE REMOVED FROM BRINE OPERATION (LB)
070 080
Ckt Ckt Ckt Ckt
A B A B
0.8 1.1 1.1 1.1
approximately 15 to 17°F (–9.4 to –8.3°C). Refrigerant VAPOR
only may be added to a circuit through the
connection on the suction line.

Charge Adjustment for Brine Operation

For 30RAP010-060 units, the 30RAP chiller does not require a
medium temperature brine modification at any temperature within
the chiller application range which is as low as 14°F (–10°C) leav-
ing fluid temperature.
For 30RAP070-150 units with MCHX condenser, see Table 28 for
proper charge adjustment. For 30RAP070-150 units with RTPF
condenser, no charge adjustment is needed.
Never charge liquid into low-pressure side of system. Do not
overcharge. Overcharging results in higher discharge pres-
sure, possible compressor damage, and higher power con-
sumption. During charging or removal of refrigerant, be sure
water is continuously circulating through the cooler to prevent
freezing.

Operating Limitations

COOLER FLOW RATES AND LOOP VOLUMES

Refer to Table 29 for minimum and maximum cooler flow rates,
and to Table 30 for minimum fluid volume requirements.
TEMPERATURES (See Table 31 for 30RAP standard tempera-
ture limits.)
Do not operate with cooler leaving chiller water (fluid) tem-
perature (LCWT) below 40°F (4.4°C) without an appropriate
concentration of an inhibited antifreeze solution. Units should
not be operated below 15°F (–9.4°C) when configured for
medium temperature brine. Damage to the cooler and/or com-
pressor(s) may result.
High Cooler Leaving Chilled Water (Fluid) Temperatures
(LCWT)
During start-up with cooler LCWT above approximately 60°F
(16°C), the unit expansion valve will limit suction pressure to ap-
proximately 142 psig (929 kPa) to avoid overloading the compres-
sor.
Low Cooler LCWT
For standard units, the LCWT must be no lower than 40°F
(4.4°C). If the unit is the factory-installed optional medium tem-
perature brine unit, the cooler LCWT can go down to 15°F
(–9.4°C).
090 100
Ckt Ckt Ckt Ckt
A B A B
No Change is Needed
1.1 1.1 1.1 2.0
52
/ in. suction Schrader
1
4
CAUTION
CAUTION
115 130
Ckt Ckt Ckt Ckt
A B A B
2.0 2.0 2.0 3.0
150
Ckt Ckt
A B
3.0 3.0