Part-winding motor starting ATL?
Part-winding motor starting ATL?
(OP)
Can a 3-phase, 460v, 6 lead motor wound for a part winding start be started across the line by tying together leads 1&7, 2&8, 3&9?? Even if possible, is this a good practice??





RE: Part-winding motor starting ATL?
Is it a good practice? Only you can decide that. Someone went out of their way to specify a part winding start; it takes a special motor and starter. Second guessing that decision may leave you open to whatever problem they were trying to solve.
RE: Part-winding motor starting ATL?
RE: Part-winding motor starting ATL?
Quote: "Part Winding: This method used only a portion (usually one-half, but sometimes two-thirds) of the motor winding, increasing the impedance seen by the power system. It is to be used only for voltage recovery, and must not be left on the start connection for more than 2 to 3 seconds. The motor is not expected to accelerate on the start connection, and may not even turn.
Starting Characteristics: Starting current is 60-75% of full load, depending on the specific winding connection. Starting torque is low typically 50% (may not even turn the shaft). Winding heating is very high on start connection.
Applications: Where power system has automatic voltage recovery and normal inrush would cause unacceptable voltage dip. Should not stay on start connection more than 2 to 3 seconds."
Our motor turned out to be series wye on start (half of the winding in) & parallel wye on run (whole winding). It was tagged the same as you mention for run connection.
RE: Part-winding motor starting ATL?
Yes you can do that, but take account the DOL Curent will be greater than PW Start.From the U.S Electrical Motors technicall Information : "This method used only a portion (usually one-half, but sometimes two-thirds) of the motor winding, increasing the impedance seen by the power system. It is to be used only for voltage recovery, and must not be left on the start connection for more than 2 to 3 seconds. The motor is not expected to accelerate on the start connection, and may not even turn.
Part Winding Start
Starting Characteristics:
1. Starting current is 60-75% of normal, depending on the specific winding connection.
2. Starting torque is very low (may not even turn the shaft).
3. Winding heating is very high on start connection.
Applications:
Where power system has automatic voltage recovery and normal inrush would cause unacceptable voltage dip. Should not stay on start connection more than 2 to 3 seconds"
Regards
Petronila
RE: Part-winding motor starting ATL?
RE: Part-winding motor starting ATL?
It's available on-line, print at your own expense
http://www.usmotors.com/Products/ac_hsc.pdf