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.
IMPORTANT: Glycol antifreeze solutions are highly recommended since heater tapes provide no protection in the event of a power failure.
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
| ACCESSORY | | UNIT SIZE 30RAP | |
| PART NO. | | | | | |
| 010,015 | 018,020 | 025,030 | 035,040 | 045-060 |
| 30RA-900--- |
| | | | | |
| 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.
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.
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.
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
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.
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: Operating unit on improper supply voltage or with excessive phase imbalance constitutes abuse and may affect Carrier warranty.
