Must supply 3Ø, 480V to 200HP screw compressor. Starter is westinghouse autotransformer, closed transition. Motor is 209 FLA.
The expensive option invloves lots of new conduit and cable run through a heavily plumbed space.
Would like NEC refferents and opinions on legality/ advisability of the following proposal.
Adjacent to the starter cabinet is a square D panel board;
400A main breaker in position 2, magnetic pickup on this breaker adjustable to 6x;
The panel has a number of branch ciruits already; however, most are trivial or obsolete. total steady load would not excede 100A.
Can we install a 400A adjustable instantaneous trip CB in the panelboard to feed the starter?
Calculated start I should be ~700A at the present auto transformer tap. Motor overload protection is integral to the starter.
The expensive option invloves lots of new conduit and cable run through a heavily plumbed space.
Would like NEC refferents and opinions on legality/ advisability of the following proposal.
Adjacent to the starter cabinet is a square D panel board;
400A main breaker in position 2, magnetic pickup on this breaker adjustable to 6x;
The panel has a number of branch ciruits already; however, most are trivial or obsolete. total steady load would not excede 100A.
Can we install a 400A adjustable instantaneous trip CB in the panelboard to feed the starter?
Calculated start I should be ~700A at the present auto transformer tap. Motor overload protection is integral to the starter.