Precautions for power distribution of screw chillers

Precautions for power distribution of screw chillers

1. After the screw chiller arrives at the customer site, it is necessary to connect the power cord to the unit control cabinet. The inlet of the control cabinet is above the control cabinet. The power inlet of the chiller control cabinet must be 1 meter higher than the unit, and the control cabinet must not be under pressure. Connect the power cables to the terminals R, S, T, N, and after the first 24 hours (the shortest time allowed), the terminals need to be tightened again.

　　2. In addition to the screw-type chiller itself controlling the electric box, an electric control cabinet supporting the water pump and the water tower fan is also required. The power part of the electric control cabinet includes: the main power wiring copper bar, and the Y-Δ compressor starting electrical device.

　　 3. The domestic standard screw chiller working power supply is 3N~, AC380V, 50Hz. The external power supply must conform to the electrical characteristics of the unit to ensure the service life of the unit. The voltage deviation of the power supply is preferably less than 5%. The total power supply is connected through the upper threaded hole on the back of the electric control cabinet of the chiller unit and connected to the power wiring copper bar or terminal block , Complete the power supply wiring.

　　 4. The installation of all power supply circuits should be carried out in accordance with the National Electrical Code.

　　 5. The specifications of the power cord connected to the screw chiller control cabinet should be selected according to the rated current on the nameplate. The total power supply must be equipped with a certain margin, and the recommended value is 1.25 to 1.3 times or more of the parameters of the unit, water pump, and water tower. The current carrying capacity of the power supply cable (wire) should be slightly larger than the maximum operating current of the chiller, and the influence of the working environment should be considered. The electric control box is equipped with ground wire connection and automatic disconnection measures. The power supply provided by the user must be equipped with this measure. For high-current units, dual power supplies should be used, but the diameter of the two power supplies must be equal and of the same brand.