In the 277/480 VAC system the phase to neutral (and typically ground) voltage is 277 VAC. The difference phase angle makes the phase to phase voltage 480 VAC (not 277*3 = 831 VAC).
In the 120/208 VAC system the phase to neutral voltage is 120 VAC - so your right. To get 120 VAC for a wall outlet you take one phase of the three phase system. You still need a transformer to get from 277/480 to 120/208.
In the 380 VDC system there will only be one transformer/rectifier (277/480 VAC to 380 VDC). Assume that it has an efficency around 90% (typical). In your normal data center you would go from 277/480 VAC to 120/208 VAC with a transformer (90%), then to 5/12/24 VDC with another smaller transformer (most likely 80-85% efficent due to the small size).
You probably don't realize that most of the lighting and mechanical systems in your data center are already 277/480 VAC. That is the standard power configuration for a new commercial building (cuts down on conductor sizes). There is a dedicated transformer to create 120 VAC for all the plug loads.
In a properly designed DC system, your no more/less safe than your already are.
(Sorry for the repost - I finally remembered my login)
processor : 0
vendor_id : unknown
cpu family : 4
model : 0
model name : 486
stepping : unknown
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : no
cpuid level : -1
wp : yes
flags :
bogomips : 59.80
While encryption at this point makes some sense, doesn't that mean the video card will need to decrypt the data stream at some point?
What about when (not if) the encryption gets broken? Better get ready to flash your video card bios! Or worse, in addition to forced OS upgrades, now you'll have forced video card upgrades every 3-months (if I were a vido card manuf. that doesn't seem so bad now, does it?)
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In the 120/208 VAC system the phase to neutral voltage is 120 VAC - so your right. To get 120 VAC for a wall outlet you take one phase of the three phase system. You still need a transformer to get from 277/480 to 120/208.
15% seems right on to me.
- EB
In a properly designed DC system, your no more/less safe than your already are.
(Sorry for the repost - I finally remembered my login)
But it was my fault for skipping over the first sentence in the parent.
Slack runs great on old hardware - I've got my old 486 from college running slack 9.1 simply because I can:
root@boxybrown:/home/acwalbur# uname -a
Linux boxybrown 2.4.26 #1 Wed Sep 8 09:52:45 EDT 2004 i486 unknown unknown GNU/Linux
root@boxybrown:/home/acwalbur# cat /proc/cpuinfo
processor : 0 vendor_id : unknown cpu family : 4 model : 0 model name : 486 stepping : unknown fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : no cpuid level : -1 wp : yes flags : bogomips : 59.80
59.8 Bogomips! It's a real screamer!
What about when (not if) the encryption gets broken? Better get ready to flash your video card bios! Or worse, in addition to forced OS upgrades, now you'll have forced video card upgrades every 3-months (if I were a vido card manuf. that doesn't seem so bad now, does it?)
- Adam