Which is power supply B on the BACK of a catalyst 3850 48 port switch ?

[paul.wilk]

I think Power Supply A is on the left and B is on the right when looking at the back of a 3850 Catalyst switch.

[Mark Malone]

Yes   , these ps are hot swappable , pull one and check the show env and you will see which one is down ,if you pull the left it should show 1A status down

switch can operate fine with 1 Ps so it wont effect anything

[Robin Burns]

I just tested a dual power-supply WS-C3850-48P-S.  The B unit is the one along the outside of the switch.  That would be to the right when looking at the back of the switch.

A is the one towards the middle of the switch. 

[Swapnil_Patel]

When you see Power Supply back panel from back side,

Power Supply A is your left and Power Supply B is on your right side. 

Since they are hotswap able, Feel free to keep one ON and remove second. 

show environment power
SW PID Serial# Status Sys Pwr PoE Pwr Watts
-- ------------------ ---------- --------------- ------- ------- -----
1A PWR-C1-1100WAC XXXXXXX OK Good Good 1100
1B PWR-C1-1100WAC XXXXXXX OK Good Good 1100