Tradeoffs in Motor Branch Circuit Protection

Under the National Electrical Code, an engineer designing a motor branch circuit has the option of selecting motor short circuit protectors (MSCP´s), one of two kinds of circuit breakers, or one of several classes of fuses for his short circuit protection means. In making his decision, he evaluates initial cost, convenience, degree of protection, replacement cost, etc. This paper outlines these tradeoffs in a concise manner so that an individual selecting short circuit protection for a motor branch circuit can be aware of them and select the protective device which optimizes the concerns he feels are most important.