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The other method for reducing flow on a constant speed
pump is impeller trimming. The impellers in the pumps provid-
ed in the 30RAP hydronic kit are easily removable for this pur-
pose. Refer to the ITT literature packet supplied with the
hydronic package information on Seal Replacement in the
Service Section, and follow its instructions for impeller remov-
al. Trimming should only be done by a qualified machine shop
that has experience in this operation. Contact your local Carrier
representative for a recommended machine shop. After trim-
ming, the impeller MUST be balanced. Failure to balance
trimmed impellers can result in excessive vibration, noise, and
premature bearing failure.
Impeller trimming has the added benefit of maximum bhp
savings. It is very possible for power savings to pay for the
trimming cost very quickly. The 30RAP pump option may be
applied with a field-supplied VFD. When applied with a VFD,
the maximum length of wiring between the drive and the pump
motor is 50 ft (15.2 m). The maximum allowable carrier fre-
quency of the inverter is 12 kHz, with 3 kHz recommended.
PREPARATION FOR YEAR-ROUND OPERATION — If
the unit is in operation year-round, add sufficient suitable
inhibited antifreeze solution such as propylene or ethylene gly-
col to chilled water to prevent freezing under low-ambient
temperature operating conditions. Consult a local water treat-
ment specialist on characteristics of water and recommended
inhibitor.
Motormaster
®
low ambient temperature head pressure control
is required if ambient temperatures are below 45 F (7 C) on
size 018-030 units, and 32 F (0° C) on size 035-060 units.
Motormaster is standard on size 010 and 015 units,
Accessory wind baffles are required with Motormaster head
pressure control if the wind velocity is anticipated to be greater
than 5 mph (8 km/h). Unit sizes 010-030 require one baffle and
unit sizes 035-060 require two baffles. See Table 8.
Table 8 — Wind Baffle Accessory Quantities
FREEZE PROTECTION — The 30RAP units are provided
with a water strainer and a flow switch to protect against freez-
ing situations that occur from no water flow. While the flow
switch (thermal dispersion) is helpful in preventing freezing
during no-flow situations, it does not protect the chiller in case
of power failure, or in other cases where water temperature
falls below the freezing mark. Appropriate concentrations of
inhibited ethylene glycol or other suitable inhibited antifreeze
solution should be considered for chiller protection where am-
bient temperatures are expected to fall below 32 F (0.0° C).
Consult local water treatment specialist on characteristics of
the system water and add a recommended inhibitor to the
chilled water.
1. If the pump will be subjected to freezing temperatures,
steps must be taken to prevent freeze damage. If the
pump will not be used during this time, it is recommend-
ed to drain the pump and hydronic package and these
components back-flushed with inhibited glycol. Other-
wise, a glycol-water solution should be considered as the
heat transfer fluid. Units have a drain mounted on the pip-
ing leaving the heat exchanger. Drains are located on the
sheet metal base of all units.
NOTE: Do not use automobile antifreeze, or any other fluid
that is not approved for heat exchanger duty. Only use appro-
priately inhibited glycols, concentrated to provide adequate
protection for the temperature considered.
2. Use an electric tape heater for the internal piping (exclud-
ing those within the pump box) if unit will be exposed to
freezing temperature.
3. Ensure that power is available to the chiller at all times,
even during the off-season, so that the pump and cooler
heaters have power. Also make sure that the piping tape
heaters have power.
4. On units with pump packages, a heater is supplied in the
pump box that will protect this section from freezing in
outdoor-air temperatures down to –20 F (–29 C), except
in case of a power failure.
5. Cooler heaters that will protect down to –20 F (–29 C)
can be installed as a factory option. It should be noted that
these heaters will not protect the cooler from freezing in
the event of a power failure.
PREPARATION FOR WINTER SHUTDOWN — Do not
shut off power disconnect during off-season shutdown. At the
end of the cooling season:
1. Drain water from system.
2. Replace drain plug(s) and add sufficient inhibited ethyl-
ene glycol (or other suitable inhibited antifreeze) to
cooler, pump and piping to prevent freezing of residual
water.
3. At the beginning of the next cooling season, refill cooler
and add recommended inhibitor.
Step 5 — Make Electrical Connections
POWER SUPPLY — Electrical characteristics of available
power supply must agree with unit nameplate rating. Field
wiring size and supply voltage must be within limits shown in
Table 9. See Tables 10-17 for component electrical data.
IMPORTANT: Glycol antifreeze solutions are highly
recommended since heater tapes provide no protection
in the event of a power failure.
ACCESSORY
PART NO.
30RA-900---
UNIT SIZE 30RAP
010,015 018,020 025,030 035,040 045-060
054 1————
055 —1—2—
056 ——1 — 2
CAUTION
To avoid damage to refrigerant coils and electronic compo-
nents, use extreme care when drilling screw holes and
attaching fasteners.
CAUTION
Do not circulate water through unit without strainer in
place. Failure to use the strainer represents abuse and may
impair or otherwise negatively affect the Carrier product
warranty.
WARNING
Electrical shock can cause personal injury and death. Shut
off all power to this equipment during installation. There
may be more than one disconnect switch. Tag all discon-
nect locations to alert others not to restore power until work
is completed.
IMPORTANT: Operating unit on improper supply voltage
or with excessive phase imbalance constitutes abuse and
may affect Carrier warranty.