# Start, run



## Majack16 (Jun 13, 2011)

theres a 3-phase 277v motor at work that has 12 leads. there is a diagram for start ( L1-1, L2-2, L3-3, 4-7, 5-8, 6-9, 10-11-12) and a diagram for run (L1-1-12, L2-2-10, L3-3-11, 4-7, 5-8, 6-9) what is the difference in the wiring? someone had said at work that start is for testing.?.?. i am looking for a more technical answer.


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## Big John (May 23, 2010)

That motor is called wye-start/delta-run. 

When motor is designed to run with the windings in the delta configuration (that second connection scheme) which provides full torque and will draw the nameplate current.

When the motor is started with the same voltage applied to a wye-connection (that first connection scheme) it draws significantly less current and produces a lot less torque. This allows for the driven load to be brought up to speed more gradually.

-John


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## Majack16 (Jun 13, 2011)

thank you


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