Cisco 4000 switch with supervisor module II+

[abbas.ali]

I have a above switch with redundant power supplies in Bay 1 and 2.  The status indicator is green on the supervisor module, but turns amber when we shutdown one of the power supplies.  The switch functions fine with only 1 power supply, but wondering why the status turns amber from green.

Thanks

[glen.grant]

   That is a system warning light and it will turn amber when one of the installed power supplies is turned off  or fails .  This is a normal function.  It may not go amber if you actually pulled the power supply out of the slot where it could not sense  there was a power supply actually installed in that slot , don't know for sure though... The 2nd power supply is there for redundancy in case one fails .   Whats better having a spare running or  having a whole switch of potentially hundreds  of  users down until you can find a replacement..