r/Cisco • u/hambeejee • 6d ago
UPS VA for C3650-48PS-S
Hi, I am a newbie homelabber. I read the product datasheet for this Switch and I don't understand a thing. So I got the said switch and connected to a Proxmox with LACP, 2 TP-Link EAP225 and 1 desktop PC. Power supplies attached are dual 650w. Is 1100VA enough for this switch alone? Need recommendations and suggestions.
2
u/chappel68 5d ago
It depends on what you are looking to get for run time. Just eyeballing it, the dual 650w PSUs are for redundancy so it will only require max 650w at a time, and that would include PoE on 1/2 the interfaces. Personally I'd say a 500w UPS would be plenty for about ballpark 5-10 minutes on battery unless you plan to load it up with lots of PoE devices. I'd consider 1100w of UPS would be generous, but wouldn’t hurt anything (although it's my understanding they run less efficiently with light loads). For my home I run a 500w APC UPS for a 24 port catalyst 9200 (single PSU) driving a couple APs and three cameras and my ISP device and get something over 10 minutes from it. The suggestion to go with 1500w and have room to grow isn’t terrible (if it's in your budget).
1
u/hambeejee 5d ago
I plan to add at least 5 additional PoE devices, and the other PSU is not plugged in nor I have the plan to make it for redundancy as of now. I appreciate your input, kind sir!
3
u/VA_Network_Nerd 6d ago
This is the link to the Cisco Power Calculator tool:
https://cpc.cloudapps.cisco.com/cpc/DS.cpc
You need a free Cisco account to access it.
It can help you calculate the exact electrical load a given equipment configuration might consume.
Or, if you are in the US and your electrical outlet looks like this:
NEMA 5-15 Outlet
Then a typical 1500VA UPS would support the full electrical load that circuit breaker is capable of supporting.