Carrier 50VZ Installation, Operation And Maintenance Instructions

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Carrier 50VZ Installation, Operation And Maintenance Instructions Manual pdf 30 page image

30For both option A (Figure 22) and option B (Figure 23) thefollowing conditions should be observed:- The maximum speed permitted in any line is 15 m/s.- Suction line must be insulated and have a 2% slope towardsthe compressor and the horizontal pipe run.- In long pipe runs it may be necessary to adjust the oil charge.- If the liquid line flow is downward, it is necessary toinstall pressure equalizer for heights above 10 m.- The liquid should be subcooled by at least 1 K at therestrictor inlet. In this case, if the liquid line flow isupward and the pipe is longer than 15 m, it must besubcooled by 1 K for each 3.5 m in excess of 15 m.- Subcooling can be contained in the liquid and suctionlines (maximum 15 m) of the units.- For each metre of refrigerant pipe installed, refrigerant hasto be added in accordance with table 3.Table 3 - Refrigerant charge (g/m)Diameter 1/2" 5/8" 3/4" 7/8" 1-1/8" 1-3/8"Liquid line 75 120 180 250 420 645Suction line 14 23 34 47 81 123SizingSuction/discharge lineThe gas line is the suction line in cooling and the dischargeline in heat pump operation. Its diameter is calculated for themost unfavourable condition. This can be as a suction or as adischarge line and has to be checked afterwards for the otherline type.For example, in the configuration shown in option A (the suctionspeed will produce the most unfavourable condition, and thegas line diameter will be calculated for suction. Afterwards, thecalculation should be checked for discharge. The diametercalculation for suction and discharge lines is done in the sameway using the corresponding drawing (see Figs. 24 and 25).Fig. 24 - Suction lineFig. 25 - Discharge lineLegend:38VZ/PZ 015 + 40PZ 01538VZ/PZ 031 + 40PZ 03138VZ/PZ 040 + 40PZ 04038VZ/PZ 025 + 40PZ 02538VZ/PZ 045 + 40PZ 04538VZ/PZ 030 + 40PZ 03038VZ/PZ 055 + 40PZ 05538VZ/PZ 065 + 40PZ 06538VZ/PZ 075 + 40PZ 075Legend:38VZ/PZ 015 + 40PZ 01538VZ/PZ 031 + 40PZ 03138VZ/PZ 040 + 40PZ 04038VZ/PZ 025 + 40PZ 02538VZ/PZ 045 + 40PZ 04538VZ/PZ 030 + 40PZ 03038VZ/PZ 055 + 40PZ 05538VZ/PZ 065 + 40PZ 06538VZ/PZ 075 + 40PZ 075From Figures 24 and 25, for the selected unit we can obtain thepressure drop corresponding to 10 m of equivalent length foreach diameter.For other equivalent lengths, the pressure drop is obtained indirect proportion. The total pressure drop for the line (sumcorresponding to the vertical and horizontal pipe runs) mustnot be higher than 20 kPa.Liquid line:The liquid line diameter can be selected using table 4.Table 4 - Liquid lineModels Total equivalent lengthUp to 10 m From 10-30 m From 30-50 m38VZ/PZ 015 + 40PZ 015 5/8" 5/8" 5/8"38VZ/PZ 025 + 40PZ 025 5/8" 5/8" 3/4"38VZ/PZ 030 + 40PZ 030 5/8" 3/4" 3/4"38VZ/PZ 031 + 40PZ 031 5/8" 5/8" 5/8"38VZ/PZ 040 + 40PZ 040 5/8" 5/8" 5/8"38VZ/PZ 045 + 40PZ 045 5/8" 5/8" 3/4"38VZ/PZ 055 + 40PZ 055 5/8" 3/4" 3/4"38VZ/PZ 065 + 40PZ 065 5/8" 3/4" 7/8"38VZ/PZ 075 + 40PZ 075 3/4" 7/8" 7/8"Necessary checks/precautions before start-up- Ensure that all electrical connections are properlytightened.- Ensure that the unit is level and well-supported.- Check the condition of the ductwork in case damage hasoccurred during installation.- The air filter should be clean and in place.- All the panels should be fitted and firmly secured with thecorresponding screws.- Make sure that there is sufficient space for servicing andmaintenance purposes.SPEED (m/s)SPEED (m/s)