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Why do we set in a thermal overload relay in star-delta starters at 58% of the <br />rated motor current?<br />

Product Line:
NEMA style Overload Relays

 Because of the way the connection is made in RUN(delta) mode, the full load current is shared across the 1M and 2M contactors. Because of this, the thermal units must be sized at 58% of the motor full load current rating.

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