A VFD manufacturer is proposing to utilize a motor circuit protector for the incoming disconnect switch in lieu of a circuit breaker. Is this kosher? I thought you could only use a motor circuit protector if it was part of a UL listed combination starter assembly. If so, what does UL listed combination need to include? Does the actual breaker needed to be tested as part of the assembly? So if they are proposing a cutler hammer MCP with a AB VFD does this actual combination need to be tested?
Any informative thoughts would be appreciated.