POWER WIRING — All power wiring must comply with applicable local and national codes. Install field-supplied branch circuit fused disconnect per NEC (National Electric Code, U.S.A.) of a type can be locked OFF or ON. Disconnect must be within sight from and readily accessible from unit in compliance with NEC Article 440-14.
General Wiring Notes
1.The control circuit does NOT require a separate power source. Control circuit power is obtained by a step-down transformer from the main three-phase power supply. The LVT (low voltage terminal) strip is provided for field- wired control devices.
2.Cooler and pump heaters (if factory installed) are wired in the control circuit so they are operable as long as the main power supply to the unit is ON. A factory-installed and set overload device protects them.
NOTE: The field-supplied disconnect should never be off except when unit is being serviced or is to be down for a pro- longed period, in which case cooler should be drained.
3.Power entry is at the right-hand side of the unit when fac- ing the control box.
4.Maximum field wire sizes allowed by lugs on terminal block/non-fused disconnect are listed in Table 8.
5.Terminals for field power supply are suitable for copper conductors. Insulation must be rated 167 F (75 C) minimum.
FIELD CONNECTIONS
Main Power — Bring wires from the fused disconnect switch through hole in the middle of the right hand corner post to the bottom of the control box and connect to terminals on terminal block or non-fused disconnect. A 7/8-in. hole is provided in the corner post to locate the center of the field power entry. To comply with NEC Article 440-14, the disconnect must be lo- cated within sight from and readily accessible from unit. Refer to Fig. 19.
IMPORTANT: To ensure power to the heaters, make sure auxiliary power to the unit and the compressor circuit breakers is always on (except for servicing or prolonged shutdown).
CAUTION
Proper rotation of condenser fan(s) MUST be verified before pumps or compressors are started. Consult the Con- trols, Start-Up and Operation manual provided with this chiller for correct procedure. Improper pump rotation can cause permanent damage to pump impeller and housing. If pump(s) have been removed for trimming, verify that wir- ing is reconnected in the original manner.
Control Power — Control power is obtained from the main power supply and does NOT require a separate source. A toggle switch (marked Emergency On-Off on the unit label diagram and by the switch) allows the control circuit to be manually disconnected when necessary. Cooler and pump heaters (if installed) are in an operable state when this switch is in the Off position.
Step 6 — Install Accessories
ELECTRICAL — A number of electrical accessories are available to provide the following optional features (for details, refer to the Controls, Start-Up, Operation, Service, and Troubleshooting book):
Energy Management Module (Used for any of the following types of temperature reset, demand limit and ice features):
•4 to 20 mA leaving fluid temperature reset (requires field-supplied 4 to 20 mA generator)
•4 to 20 mA cooling set point reset (requires field- supplied 4 to 20 mA generator)
•Discrete inputs for 2-step demand limit (requires field- supplied dry contacts)
•4 to 20 mA demand limit (requires field-supplied 4 to 20 mA generator)
•Discrete input for Ice Done switch (requires field- supplied dry contacts)
Navigator™ Display — The device provides hand-held, mobile capability using an easy to read 4-line display. The key- pad function is the same as the scrolling marquee module. A magnet is provided for ‘hands free’ service of components.
Low Ambient Operation — If outdoor ambient operating temperatures below 45 F (7 C) on size 018-030 units or 32 F (0° C) on size 035-060 units are expected, refer to separate in- stallation instructions for low-ambient operation using accesso- ry Motormaster® V control. Size 010 and 015 units have Mo- tormaster V installed as standard.
Minimum Load Accessory — If minimum load accessory is required, refer to unit Price Pages or contact your local Carrier representative for more details. For installation details, refer to separate installation instructions supplied with the accessory package.
Miscellaneous Accessories — For applications requiring spe- cial accessories, the following packages are available: external vibration, remote enhanced display, temperature reset, con- denser coil covers, storage tank, wind baffles, and remote cool- er. For installation details, refer to separate installation instruc- tions supplied with these accessory packages.
Step 7 — Check Refrigerant Circuit
LEAK TESTING — Units are shipped with complete operat- ing charge of R-410A (refer to physical data tables) and should be under sufficient pressure to conduct a leak test. Perform a leak test to ensure that leaks have not developed during unit shipment. Dehydration of the system is not required unless the entire refrigerant charge has been lost. Repair any leak found using good refrigeration practice.
DEHYDRATION — Refer to Carrier Standard Service Tech- niques Manual, Chapter 1, Refrigerants, Sections 6 and 7 for details. Do not use compressor to evacuate system.
REFRIGERANT CHARGE (Refer to Tables 1A and 1B) — Immediately after the condenser coil in each circuit is a 1/4-in. Schrader connection for charging liquid refrigerant.
Utilization of Novation condenser coil technology enables the 30RAP chiller to have a very low refrigerant charge. There- fore, if field charging is required, accurately charging to the correct quantity is very important. It is necessary to ensure that the system is completely evacuated before charging and that the refrigerant charge is accurately weighed to within 1% of the nameplate quantity or the unit may not operate correctly.
CAUTION
When charging, circulate water through the cooler at all times to prevent freezing. Freezing damage is considered abuse and may impair or otherwise negatively affect the Carrier warranty.
CAUTION
DO NOT OVERCHARGE system. Overcharging results in higher discharge pressure, increased power consump- tion, and possible compressor damage.
The suction lines are provided with a 1/4-in. Schrader fitting for connecting to low-side system pressure. The location of the suction access port is shown in Fig. 20.
