Table 430-152 lists the maximum setting of 250%. This can be changed per 430-52(c)(1)(c)to 400% for loads of 100A or less. I think Uglies is looking at the breaker as disconnecting means per 430-110. This gives a minimum 115%. Where I work we use mimimum 150% on motor circuit breakers with a maximum of 400%. I think the only other consideration would be given to the locked rotor amp rating.
Still, 150% of 40 would be a 60 amp breaker. Are they using 175%? I can't think of any reason in particular they would use that. Edit from here, I looked at the wrong column.
[This message has been edited by rad74ss (edited 03-16-2005).]