Hanbell RC2-D, Техническое руководство

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RC2-D Technical Manual
4. Electrical parameters and design
4.1 Start-up
The standard startup mode of Hanbell RC2-D series screw compressor is Y-Δ startup.
1) Y-Δ start-up
Y-Δ connection mode is Y shape connection when start-up. At this time, the voltage on the winding is
reduced to 1/ 3 of the input voltage. After the start-up, re-connect to the delta shape. By this starting
model, we can reduce the starting current by the reducing the starting voltage, which is also called
step-down start.
Figure 4-1 Y-Δ Connection diagram
Note : After the Y - shape startup, the MCM & MCS conversion takes 0.25 seconds, and the MCM
& MCD gets the power to conduct the delta operation. In 0.25 seconds, it may cause pseudo short
circuit due to improper contactor action, resulting in compressor jumping. When this happens, it is
recommended to use an adjustable Y-
Δ
time relay or delay device to extend the conversion of
MCM and MCD, and the power gain time is about 0.25 to 0.5 seconds. Please refer to the Y-
Δ
Conversion Time Diagram for specific information.
In Y-connection, MCM and MCS are electrified to make Z, X and Y become the center of Y
connection. After a few seconds (3-5 seconds recommended), the MCM and MCS are disconnected.
After about 0.25 seconds, the MCM and MCD are powered on, and at this time, they are converted
to
Δ
shape connection. Y-
Δ
conversion time diagram is shown in Figure 4-2.