Sorry to mention that it's not MCCB. It is 460 VAC-3 phase fusible disconnect rotary switch.The details matter, but in general where you choose to locate a disconnect is up to you. I have been known to install a main MCCB at the bottom of a control panel and reverse feed it because the incoming feeder is underground and it will make it a lot easier for the electrician to hook it up.
I will say that most disconnect switches are not labeled to allow them to be reverse fed, while many MCCBs are labeled to be reverse fed.
1. the disconnect switch (DS) is not facing down. It's installed on the bottom of the panel and all control devices are directly above it.Doesn't matter. Why do you think it's a problem?
Are you talking about facing the switch downwards on the bottom of the cabinet? Or just one enclosure below another?
How would dropping something on a live wire at the bottom of the cabinet be more hazardous than dropping it on something live at the top of the cabinet.The switch is not enclosed as MCCB and its leads are more exposed. If it's installed on the bottom, it creates more hazard if something above it dropped on the lines.
The difference is DS have 460VAC, while others have either 24VDC/120VAC. Which one cause more serious hazards?I suppose it is possible that something might drop onto the switch. But if something came loose and something other than the switch was under it you would have the same problem.
If the DS has 480 VAC on it, there is a good chance other things in the cabinet also do.The difference is DS have 460VAC, while others have either 24VDC/120VAC. Which one cause more serious hazards?