Carrier 19EX, 17 Ð Water Piping, Oil Cooler to Chilled Water Circuit Typical

Fig. 15 Ð Water Piping, Oil Cooler to

Chilled Water Circuit (Typical)

INSTALL VENT PIPING TO RELIEF DEVICES Ð The 17/19EX chiller is factory equipped with relief devices on the cooler and utility vessels. Refer to Fig. 2 and 3, and Table 13 for size and location of relief devices, as well as information that will help determine pipe size. Vent relief devices to the outdoors in accordance with ASHRAE 15 (latest edition) Safety Code for Mechanical Refrigeration and all other applicable codes. To ensure relief valve serviceabil- ity, and as required in ASHRAE 15, latest edition, 3-way dual shutoff valves and redundant relief valves are installed on the economizer/storage vessel, refer to Fig. 16.

NOTE: The 3-way dual shutoff valve should be either front seated or back seated. Running the refrigeration system with the valve stem in the center position can reduce total relief capacity and cause valve chattering.

Refrigerant discharged into con®ned spaces can dis- place oxygen and cause asphyxiation.

1.If relief device piping is manifolded, the cross-sectional area of the relief pipe must at least equal the sum of the areas required for individual relief pipes.

2.Provide a pipe plug near outlet side of each relief device for leak testing. Provide pipe ®ttings that allow vent pip- ing to be disconnected periodically for inspection of valve mechanism.

3.Piping to relief devices must not apply stress to the device. Adequately support piping. A length of ¯exible tubing or piping near the device is essential on spring- isolated machines.

4.Cover the outdoor vent with a rain cap and place a con- densation drain at the low point in the vent piping to pre- vent water build-up on the atmospheric side of the relief device.

Make Electrical Connections Ð Field wiring must be installed in accordance with job wiring diagrams and all applicable electrical codes.

Fig. 16 Ð Typical 17/19EX Utility Vessel

Relief Valve Tee

Do not run 120-v wiring into the control center. The control center should only be used for additional extra low-voltage wiring (50 v maximum).

Wiring diagrams in this publication (Fig. 17-23) are for reference only and are not intended for use during actual in- stallation; follow job speci®c wiring diagrams.

Speci®c electrical ratings for individual components are shown in Table 14.

Do not attempt to start compressor or oil pump Ð even for a rotation check Ð or apply test voltage of any kind while machine is under dehydration vacuum. Motor in- sulation breakdown and serious damage may result.

CONNECT CONTROL INPUTS Ð Connect the control in- put wiring from the chilled and condenser water ¯ow switches to the starter terminal strip. Wiring may also be speci®ed for a spare safety switch, and a remote start/stop contact can be wired to the starter terminal strip, as shown in Fig. 17 and

18.Additional spare sensors and Carrier Comfort Network modules may be speci®ed as well. These are wired to the machine control center as indicated in Fig. 22 and 23.

CONNECT CONTROL OUTPUTS Ð Connect auxiliary equipment, chilled and condenser water pumps, and spare alarms as required and indicated on job wiring drawings.

Connect Starter Ð Assemble and install compressor termi- nal box in desired orientation, and cut necessary conduit open- ings in conduit support plates. Attach power leads to com- pressor terminals in accordance with job wiring drawings, observing caution label in terminal box. Use only copper con- ductors. The motor must be grounded in accordance with NEC (National Electrical Code), applicable local codes, and job wiring diagrams.

IMPORTANT: Do not insulate terminals until wiring arrangement has been checked and approved by Carrier start-up personnel. Also, make sure correct phas- ing is followed for proper motor rotation.

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