Direct-on-line start motor

Compressor with a direct-on-line start motor, example of a name plate
Compressor with a direct-on-line start motor, example of a name plate

Field 1 is divided. In the first column, the second character is Δ or D. In the second column, the second character is Y. Δ or D stands for direct-on-line start in delta connection, and Y for direct-on-line start in star connection. For star-connected starting, a voltage that is √3 times higher is required.

If the motor can be connected in star or delta configuration, then fields 1, 3 and 4 contain both specifications. The figure shows a case in which only one operation mode is possible at one supply frequency, but both are possible at the other frequency.

  1. Design the motor contactor for 120% of the maximum operating current.
  2. Select only the starting mode for which data is specified on the name plate.
  3. Only operate the motor under the conditions in power supply specified on the name plate.

Starting modes