Lab shelf power solution - Page 1
Forum section: electronics / general

author: Shock
author_rank: Super Contributor
timestamp: October 09, 2018, 02:53:16 pm
content: Been deciding on the best way to go about shelf power upgrade for a while now at a decent price. Thought I'd share so others looking for ideas can weigh up the pros and cons. I ended up getting several APC PDUs shown similar as in the photo (3x15A sockets and 21x10A). Mine has current monitoring, LAN and a serial interface and I'd put it in the repair friendly category.Pros: Remote switching, group switching. Simple current monitoring and protection. No need to hunt for switches or have them in a convenient spot. If making a custom interface could be quite flexible. Ideal way to simplify wiring and mounting. Can be always resold or repurposed back into a rack later. Some have environment monitoring and advanced power redundancy features.Cons: Can be expensive unless you look for surplus units or decommissioned racks. This particular model has no physical switch button, if that is even a thing. Could be one more thing to repair if it dies, but a quick cable swap should get most things back up and running. May need to buy male to female IEC or adapter cables, again look for surplus.Not a replacement for DUT or temporary outlets but as my shelves are 600mm deep it allows me to position gear without having to dive in to find a switch. Think about walking into the room and pressing a button to turn your gear (only the essentials) on automatically into standby or even on fully depending on the gear. Sort of limitless possibilities if you mess around with the interfaces.

author: jhenderson0107
author_rank: Regular Contributor
timestamp: October 12, 2018, 09:29:11 pm
content: My rack shelves are only 300mm deep. I mounted shallow, rackmount-compatible power strips at the back edge of each shelf which provide standard outlets to each successively-lower shelf. Then, you can use conventional IEC power cords for each component. Thesehttps://www.ebay.com/itm/19-1U-12-Way-PDU-Rack-Mount-Switch-Power-Distribution-Unit-Strip-Outlet-12A-/123379556150?hash=item1cb9fe9f36rackmount power strips are only $30/ea on eBay. See image below.

author: Shock
author_rank: Super Contributor
timestamp: October 12, 2018, 11:41:09 pm
content: Nice, I've looked at your setup a few times.My PDU strips ended up being the same price as yours but brought them used as they would cost me over a thousand brand new (not going to happen). The profile is what they call ZeroU which is the same.It would have been slightly easier buying something with regular outlets but I had problems finding an affordable power strip over here that offered the same density. I wanted outlets to also be individually switchable so I don't have to leave 20-40 things on at once.Originally I planned to have individually switched outlets mounted at the front of the shelf which allowed me to easily access switches. But this meant all the power now would be looping around the test equipment so not a good idea. A bit messy and would also interfere where I want shelf lighting.The other idea I had but would require a little more cabling, was to have two sets of power outlets at either end of the shelf. At the rear the opposite problem if the shelf is busy I can't easily reach selective switches down the entire rack.So I've got individually switched outlets now, I just need a solution where I can easily select them and turn them on/off via the serial interface.

author: TheNewLab
author_rank: Frequent Contributor
timestamp: December 18, 2018, 09:32:37 am
content: I have PDUs and electrical cords bundled up like whatjhenderson0107 has.My question is with all those cords and power strips connected so close together and close to the electronic test gear..Does that create an EMI problem when generating signals and reading them on AWGs and oscilloscopes?I am wondering if I should get all shorter power cords to eliminate all those bound up electrical cordsWill that even make a difference?

author: coppercone2
author_rank: Super Contributor
timestamp: December 18, 2018, 10:36:05 am
content: you can get shielding and possibly things with ground straps if there is a problem if you mod the equipment

author: Berni
author_rank: Super Contributor
timestamp: December 18, 2018, 12:00:22 pm
content: I have a bunch of extension cords and some C13 slitter cables.That PDU does look like a rather nice solution to it. I gotta keep my eyes open for one of these.

author: BroMarduk
author_rank: Unknown
timestamp: December 19, 2018, 01:32:44 pm
content: Quote from: Berni on December 18, 2018, 12:00:22 pmI found (and like the OP stated) that in the surplus computer world, you can find a used sub $200 USD rack that many times includes a nice PDU (or two) attached to the rack.The last rack I bought for $150 USD contained two PDUs worth over $700 USD each (used prices), not to mention oodles of fiber modules.I mean, you still have to find a spot for the rack....

author: Berni
author_rank: Super Contributor
timestamp: December 20, 2018, 10:26:56 am
content: Yeah the problem with a whole rack is that you have to go get it with a trailer and have some place to put it. It certainly won't be economic to ship it.I got my rack i use for test gear for 100€ and it only included some rack mount shelves, blanking plates, sliding rails, keyboard/mouse tray with PS/2 keyboard and mouse, regular non switched power bar and a few power cables, also it came on caster wheels. Tho most of the thrown in goodies did end up very useful (Especially shelves, power stuff and wheels)For a high quality solid rack they get surprisingly heavy too. Just one side panel can easily weigh 30kg. The frame alone (stripped of all panels and doors) is still rather heavy. But will easily hold up to as many boatanchors as you can fit in it (That's my main use for it, holding the biggest and heaviest gear)