I have the 7752. It's the 20amp version of the 7750. I think I paid $75. The 7750 is probably more in demand, but not many use an ATS They are quite old, so things like the SSL support is dated. It think it supports Radius and LDAP, but the old ciphers are a concern and I wasn't willing to use them on my LDAP server. I run the ATS and my other power gear and the server IPMI/ILO on an isolated switch. Loading certs is a tremendous pain but that applies to all the APC devices I've used. That said the physical ATS works flawlessly even with sources that use different legs.

It seems that the original text of this post is not visible to everyone so posting it again here as a comment. That also means some people may see this twice! Plus it's gonna be more than one comment because my description is too long for one comment. Also, this comment does not have inline images so refer to the album for that.

Image album: https://imgur.com/a/N9gzSc5

Design goals (In order of priority):

1. Learn, tinker, automate.

2. Reduce noise, power consumption and heat.

3. Maintain high uptime and availability for both hardware and software/ services.

Operating environment:

I live in an apartment and have dedicated one room to my office, which has my desk (which I may cover at another time), a 42U Wide Rack (discussed in this post) and other equipment that I tinker with - 3D printer, electronics tinkering etc. When I started setting up my lab here, I put in one UPS to cover the one server I had at that time. Turns out that was a great idea because this building/ area seems to have a fair amount of power issues. I tend to have one outage in about 3 months lasting a few seconds to less than 5 minutes. Once in the last year I’ve seen a 30 minute outage. I’ve run a smaller lab at my parents’ for over 10 years now and have seen lots of power issues over time there as well (amongst other challenges). This forms the basis for all the power backup and routing hardware in use. The power backup systems are designed to provide at least 30-40 minutes of backup power coverage for my priority 1 systems - house network, security systems and the internet.

What’s in the rack (APC 42U SV AR2480) - Front, top to bottom:

1. Monitor connected to KVM - all devices, including my raspberry pi’s are available via this setup.

2. Left side - APC AP7752 ATS (labeled ATS1), Remote control for KVM, 2 Blanks.

3. Right side - APC AP7750 (ATS3), APC AP7752 (ATS4), APC SMT1500RM1U UPS - Remains off until a mains power failure is detected.

4. Behind monitor - APC AP7753 ATS (ATS2) - This and above are part of an elaborate arrangement of PDU/UPS/ATS' to setup power priorities for different devices.

5. Behind monitor - 2U blank spaces covered by a hinged panel. 5U Space used by a printer, Apple time machine (2TB), storage for printer paper and manuals for some of the equipment in the rack.

6. APC SMX1500RM2U UPS - labeled UPS3 - Remains off until a mains power failure is detected.

7. Synology RS815+ (4x WD 3TB RED, 16GB RAM) - labeled NAS2 - Storage for VMs, backups, timeMachine, documents, photos etc. Multiple services installed - Active Directory, RADIUS, NTPD, Log Center, Cloud Sync etc. Also runs a Debian VM which is not yet in use (Future plans).

8. Synology RS815+ (4x Samsung 850 EVO - 500GB, 6GB RAM) - labeled NAS1 - SSD Storage for VMs - My development VMs have hourly snapshots that are also synced over to NAS2 described above. Traditional backups for all VMs also go to NAS2 above.

9. Tyan 1U B7002G20V4H (2x Xeon 5620 4 Core CPUs, 48GB DDR3, No Disk) - Not actively used anymore - it’s part of my ESXi cluster and used occasionally when I need to move running VM’s off other servers for maintenance etc. (Availability/Uptime goal)

10. 2x Blank - Future expansion (Waiting on 1 Dell R210ii) - Part of my goals to reduce power consumption, power down the other ESXi servers when possible.

11. Barebones DL380 G7 - In the process of gutting this and converting it to become a chassis to run a bunch of Raspberry PI 3s to take on multiple services from my ESXi boxes (where feasible) - Plan to use the power supplies that came with the box to power the PIs and a network switch that hooks them all up. I have 3 in use now a) Asterisk PBX b) Unifi Controller c) A custom power management setup that manages scheduling and power monitoring of all hardware in the rack - this one automates turning on and off specific devices and can control UPS and PDU units to perform hardware power management etc. This also handles turning on the two backup UPS units when a power failure is detected and turning them off again when power returns.

12. HP DL380 G7 - 2x X5675 12 Core CPUs, 98GB (12x8) 1333 DDR3, 8x 1GB Network (Add-on HP NC375T Card), 512MB BBWC, HP P410, 1x HP 168GB SAS used as temp storage by VMs, 1x Samsung 850 EVO 250GB used as flash cache by ESXi, iLO3 Advanced - Primary ESXi server - Running multiple VMs - OpenNMS, APC PCNS, VCSA, 2x Windows 10 (One dedicated to misc windows specific tools like APC tools to perform firmware upgrades), Nested ESXi patched for OSX running a High Sierra VM, Multiple Linux VMs that I use for software development, web hosting and more.

13. Cisco ISR G2 2921 - 2.5GB RAM, SM-D-ES3G 3900 Module, POE capable power supply - Core router and switch for this rack. Also powers multiple POE devices - 1x UBNT AC-M-Pro, 1x AC-Pro, 1x Axis Camera, 2x Raspberry PI. Uplink to Comcast Modem in bridge mode. Came with HSEC license so I run an IPSEC site to site VPN with my parents (Another Cisco router there) and host inbound IPSEC VPN tunnels that I use to connect to any services I need at home when outside. Stock fans were super noisy so I removed those and added 4x Arctic 80MM Silent Fans, plus an AC Infinity 2U Fan Panel (visible in photos of rack rear). This has been a rock solid performer for me - never had any problems/ outages/ difficulties with it.

14. 1U Brush panel to route all network cables to the rear/ sides to connect with devices in the rack.

15. 1U Blank panel - Optional to add additional cooling fans for the router if the need arises in future. If so, plan to use a 1U AC Infinity fan panel and 3D printed guides to route air to side intakes of router.

16. HP DL580 G7 - 4x X7560 8 Core CPUs, 128GB DDR3, HP P410 with 1GB FBWC, 512MB BBWC with onboard NIC, PCI-E I/O Expansion Board giving me 6 extra PCI slots, 6x HP 168GB SAS (Hardware Raid) for ESXi, 1x Crucial 256MB Flash Cache for ESXi - Secondary ESXi server - Mostly development VMs, Some donated CPU time for different open source projects, Tinkering (Tried running multiple borrowed GPUs for mining) etc. These days this is mostly powered off to reduce power consumption and heat. I downscaled some VMs to move to the primary box and moved services off to the NAS and PIs. I also got a deal on AWS (2 years of free usage) that allowed me to migrate some always on hosting VMs.

17. APC SMX3000RM2UNC - labeled UPS2 - Main rack ups - powered on only when either of the ESXi servers is in use.

18. APC SRT3000RMXLA-NC - labeled UPS1 - Main rack ups - Online double conversion UPS provides conditioned power for the entire rack. These two UPS units combined provide enough battery backup to allow an orderly shutdown of the DL380 and DL580 when power fails (automated via PCNS). The backup UPS units take over running other devices once both UPS1 and UPS2 are out of battery.

19. Empty space below was previously used by an in rack air cooling unit that I ended up returning. Now I just store my most frequently used things like spare cables, components and parts etc for the rack.

20. Used multiple APC Rack Rails to mount things that did not come with rails like the two Synology units, Cisco router, the two storage boxes etc.

21. Foam strips on the sides are part of additional steps taken by me to sound proof this rack as much as possible. Side panels are also lined with sound dampening materials in additional to the foam panels.