Mini-guide: reading between lines of 'N+1' claims

Reading between lines of 'N+1' claims

Three contracts I parsed last month, all said "N+1 redundant":

• Contract A (Hetzner):
  
  • One generator, one UPS string
  • "N+1" means spare generator exists... at another facility 40 miles away
  • Switchover: manual, 4-6 hours
  • For that money you get a fuel tank that holds 4 hours
• Contract B (Vultr):
  
  • Two UPS modules, one canibus
  • "N+1" means they have a spare module... in a warehouse
  • Install time: next business day
  • For that money you get "electrical diversity" that shares a single utility feed
• Contract C (OVHcloud):
  
  • Actual concurrent maintainability
  • But "N+1" only on cooling, not power
  • Generator is N, no +1
  • For that money you get honest labeling at least

I am tired. Post your examples. Goal: crowdsource a checklist.

Adding two more from RFP season.

• RackNerd: "N+1" = dual feeds, same substation. We lost both in a planned utility switch. 47 minutes.
• Leaseweb: "N+1" = two chillers, one pipe. Single point of failure. Maintenance on valve took them offline.

• Ask for single-line diagram
• Ask for maintenance procedure during your tour
• Ask for last time they tested it
• Most never test.