FLA = Full Load Amps (sum of the FLA of all the electrical data)
MCA = Minimum circuit ampacity (It is chosen to guarantee that the wiring will not overheat under the expected operating conditions. The MCA should not be used to determine the normal operating current, but used for selecting wire sizes) 125% of the largest motor FLA + the remaining sum.
MOP = Maximum overcurrent protection (The maximum overcurrent protection (MOP) is the maximum circuit breaker / fuse size required to properly protect the equipment under anticipated fault conditions.) 225% of the largest motor FLA + the remaining sum.
Does this sound correct? I have seen some designs where the overcurrent device is sized the next size above the MCA and some between the MCA and MOP and some at the MOP what is the correct way? if the MCA is 175A and the MOP is 250A if would be easier to install a 200AS/200AF rather than a 40AS/250AF for space reasons in a panelboard? would the 200AS/200AF still be acceptable?