How much power do/would you drop to an equipment rack

[shenandoah75]

1) For those of you with centrally placed equipment, what'd you do for power?

The closet where i'm putting my equipment is currently on same circuit as my living room. I am powering a UPS which powers the elk panel and structured wiring components (low consumption), and had been planning on tying off the same for the AV rack. The circuit is 20 amps and except for maybe a couple of lamps, don't expect much else to be on it.

Biggest consumers i see would be:
whole house amp (somewhere in the 5A vicinity - based on russound's 8 channel consumption as an example)
HT receiver (8 amps using specs of a mid-line denon)
HTPC (9 amps based on 550 watt antec specs)

plus:
the elk, m1xep, switch, media converter, and CD/DVD/VCR/STBs etc at about .5 amps, maybe another 5AMP max

I really don't see me maxing out volume or doing heavy PC use, so i think i'd be more like half load or less - so undr 15A... So i think i'm ok? Or would i run a second circuit just to be safe (or wait to see if i ever trip a breaker)? running a romex won't be the easiest thing, but i could get it over there.

2) Also what you do for power conditioning /backup on your rack? I was looking at APC's J series backups/conditioners but max load appears to be is 1.5KW. Two of these seems like overkill. I guess i could be selective on what goes where with maybe tv/reciever on such a unit , the pc on a standard UPS, and the rest on conditions alone... recommendations (for 1 or 2 circuits)?


thx in advance
-brad

 

[shenandoah75]

Oh and one more thing i was thinking when i do the home theater, to run a power line from the HT TV's location upstairs back to this location so it could be on UPS/conditioner. Is that overkill? Would one of the JBOX surge protectors in the wall behind it be enough? i lose the UPS capability and in F, might be a little more concerned about the brown outs than spikes (i have a whole house surge)

 

[sic0048]

Well I converted a closet that did not have any power in it, so I had to run new wiring either way. I simply ran a single 12-3 romex wire and hooked it up to 2 new 20 amp circuit breakers giving me 2 20 amp circuits in the closet. That way I only ran 1 wire, but will surely have enough power for anything I need.

I am still exploring the battery backup solution myself. I think I'll need a fairly big unit, but I am still figuring out what I need and the cheapest way of getting it

 

[pkoslow]

Hi Brad,

You're in the ballpark and you're doing the right thing to research and add up the current draw of all your gear.

For client installs that are either remodel or new construction I'll specify anywhere from a single 15a circuit to two 20a circuits depending on what's being installed. In most cases it's a pair of 20a circuits as the cost differential isn't much over 15a circuits unless they're running out of room in the electrical panel.

Here's an example of the install in my own home. There's a single 20a circuit feeding the entire rack, and a 15a circuit that feeds the power supplies and security devices mounted in the closet on the wall. The Rack has an APC SmartUPS 1400 which powers the server, routers, switches, etc. The audio gear is not on UPS, but is connected to a rack mount surge suppressor. The entire rack consumes an average of 3.2 amps.

Here's some pictures... everyone likes pirctures!

Rack:

Security Gear & Power Supplies:

Cheers,
Paul

 

[IVB]

If you're not running out of room in the panel, i'd just go put 2 in. What i'm finding is that I change my mind as to what should be in one rack in one room vs the other room. Of course, i put 2 20A in one location and 1 15A in the other, and am now moving stuff from one to the other.

Putting 2 in now (or attaching 2nd outlet to an underutilized breaker) could help there.

 

[huggy59]

Personally, I recommend 2 20A circuits for most full-rack situations. It gives you options down the road. Of course, if you add things up and need more, put more circuits in.

As far as UPS capacity, you will want to read about run-times with various load factors. Most gear is rated at it's maximum current draw (which often is when it is first started up) but draws less once it's running. APC has a lot of good info about VA vs. watts, runtime on power loads, calculators, etc.

Finally, use good judgement and common sense on sizing your UPS(es) and what to put on it (them). For example, don't put anything with heater elements (laser printers, copiers, heaters, etc.) or significant large-current loads. And label the circuits if you use any extenders on UPS-backed circuits.

[story mode on] I used to support a library that had a power strip plugged into the UPS. Every weekend the servers would go down and we'd have to be back in on Monday morning to bring everything up again. Turns out one of the cleaning crew was plugging their big carpet cleaner into the strip and sucking down the battery till it died, then moving on to the next room. Taking the servers and other gear with it, of course. [story mode off]

Good luck and have fun!

 

[shenandoah75]

Thx guys...

One question, on te 12-3 romex suggestion, if i plan on potentially pulling a full 20 amps each circuit, would the neutral going to be too small? would this meet NEC?

Then again, when i added a a 100amp subpanel i used 3AWG for both hot legs and the neutral - which i guess is the same principle.

thx
-brad

 

[Sacedog]

I would go with 2 20A circuits as well. It's inexpensive, and will save you headaches down the line. At work, we need as many as 4 20a circuits for a rack, but those are on a 7' rack that is populated with all 1U servers.

So I have a question related to this. What have people done for grounds in their equipment room? Nothing, isolated ground, or gone full boar, and have a seperate earthen ground for your equipment?

 

[sic0048]

Thx guys...

One question, on te 12-3 romex suggestion, if i plan on potentially pulling a full 20 amps each circuit, would the neutral going to be too small? would this meet NEC?

Then again, when i added a a 100amp subpanel i used 3AWG for both hot legs and the neutral - which i guess is the same principle.

thx
-brad

12-3 meets code for 2 20 amp circuits - using the shared common is no problem. If you are fearful of running out of room in your panel, most manufactures also have dual circuit breakers (I've forgotten what they are really called) that fit two circuits in the space of 1 normal breaker. They are slightly more than double the cost (hence 2 regular breakers are less expensive), but can be a real help if you are running out of space. I had to hook my new circuits up using this method.

 

[electron]

I never heard of those kind of breakers before. You learn something new everyday, thanks for the tip!

 

[Sacedog]

If you are fearful of running out of room in your panel, most manufactures also have dual circuit breakers (I've forgotten what they are really called) that fit two circuits in the space of 1 normal breaker. They are slightly more than double the cost (hence 2 regular breakers are less expensive), but can be a real help if you are running out of space. I had to hook my new circuits up using this method.

Their called double pole circuit breakers, and they are nice for trying to cram more breakers into an existing panel. They also make single pole SLIM breakers that are only for one circuit, but are half the normal width of a standard single pole breaker. So if you were close to running out of room, and thought you might be adding more breakers in the future, you could add a slim one, instead of a standard.

 

[shenandoah75]

This might have been a little pricier initially, but i freed up (3) 240V double pole breaker slots by converting my range, WH, dryer to propane And i can use all those items now when the power goes out if needed (the latter two off my little honda handheld generator until i feel like buying a bigger one)

If i buy one of those ~100 amp pool load centers, i'll free up yet another

-brad

 

[huggy59]

Sacedog, in data centers I've managed/installed, we usually had special grounding because the entire data center was on massive battery backed system, like a big Leibert online power system. A ground cable was run along the concrete floor (and to the raised floor itself in raised floor installations) under each bank of racks, in addition to the standard ground in the electrical service to each rack. At some point grounding systems are tied together, though. Earth ground is a bit of a misnomer because earth potential can vary greatly from place to place or even from time of year, depending on water level, etc. Better to have a nice copper tie line at the appropriate points.

 

[huggy59]

Correct me if I'm wrong, but AFAIK, a double-pole breaker is one that has two circuits tied together mechanically - if one trips, the other does also, usually used in things like 220/240VAC breakers like ranges, hot water heaters, etc. where the load needs to be powered from two legs of the incoming grid.

But some manufacturers do make thinner breakers that provide two in the space of one standard breaker. Note that they take power from the same leg of the supply, though, so they do not work for 220/240VAC devices that need power from two legs.

 

[sic0048]

They are not double pole breakers - huggy is right - those are breakers that have two switches that are for the SAME load. These other breakers have two independant switches that control TWO loads. I think they are called duplex breakers.

Here is a photo of one - it might be a little hard to tell, but this breaker is the normal size (1U to steal a network rack term), but has two independant switches. This picture shows two 15amp circuits, but they also make them with two 20amp circuits (that is what I used). The easiest way to make sure you get the correct one is to pull out an existing breaker (obviously not a critical one) and take it to the store with you to make sure you get the correct style and size.