Auto Manual selector switch

[NickParker]

Regarding operation of Auto/Manual selector switch in a Auto change over Panel (1 out of 2) 1oo2 operation for Incomers:

Case A: When in Auto mode, if the operator changed it to manual mode, the existing closed breaker would open.
Case B: When in Auto mode, if the operator would want to change it to Manual mode and then decide to close or open the breaker.

Forum's view on using Case A or Case B is requested.

 

[thermionic1]

Our distribution subs use something like a Case B. There is a master Auto/Manual as well as Auto/Manual switches on each main and tie. Everything is clearly marked, including the voltage test switches to the sensing relays that control the scheme. I'm not sure I follow the logic of why you would want the cb to trip by placing the switch in manual.

 

[RRaghunath]

Case-B makes more sense to me.
Once I decide to disable auto changeover (that is one meaning of 'Manual' mode, isn't it!), I expect no automatic tripping, closing or any other automatic operation.
If we allow automatic tripping of existing incomer but not allow automatic closing of the other incomer, the bus is dead and that puts unnecessary pressure on the operator.
Another consideration is that I may choose manual mode as the other incomer is down for some reason and not available.