I work in the maintenance department of a mail processing plant. The plant operates numerous hi-tech sorting machines utilizing computer and electronic technology that boggles the mind.
The manufacturer of a particular piece of equipment has sent out a national maintenance order requiring that all of these machines nationwide be protected by a 50 amp breaker. So I have been instructed to swap out the current 80 amp breaker with a 50 amp breaker which was shipped to us from our national maintenance technical center. This special breaker is simply a Square D, QO, 50 amp 3 phase HACR rated breaker wich fits our particular panel.
The problem is that the original specifications for this machine required that 1/0 conductors be pulled for the equipment power with a full sized neutral and ground. The 50 amp breaker will not accommodate the 1/0 conductors. The engineers at the national maintenance center have instructed us to install a junction box at the panel and splice the 1/0 conductors with #2awg conductors using split bolt connectors, then connect the 50 amp breaker to the #2 conductors.
The machine is also protected by fuses and breakers at its disconnect panel.
This makes no sense to me. My questions are how does this affect voltage drop? And is there another better way to provide 50 amp over-current protection to 1/0 conductors?
My personal opinion is that the 80 amp breaker is adequate to protect the conductors and the machine, especially given the OCP devices on the equipment. What do you all say?
Sorry this is so long!
