20amp Circuit How many computers

You'll be just fine

Not that tough to compute if you really are a computer geek.

So factor in the peripherals - which really don't draw much at all, and you're getting pretty damn close to 20A at full draw startup.

Has no disks, and is booted from the network?

Shouldn't be a problem.

True thin client workstations are far less power hungry than their larger PC cousins. Also, keep in mind that even though a desktop PC may have a 400-watt power supply, its maximum power draw is likely to be less than half that.

Here's the scoop according to eWeek:

"While a PC can consume as much as 220 watts of power, a thin client such as Sun's Sun Ray 2FS consumes less than 8 watts. Even a thin client with a processor and DDR (double data rate) RAM such as HP's HP Compaq t5720 consumes about 30 watts or less."

Source:

One other thing to note: if these thin clients are, in fact, older generation or "obsolete" PCs that have been "reborn" as thin clients,

So with that in mind, total wattage could fall anywhere from as little as 150 to 200-watts (< 2.0 amps) at the low end, to perhaps as high as

Cheers, Paul

Well personally I would go by the wattage of the power supply, not what a magazine article tells me, but I don&#39;t manage thin clients in my data center.

I suspose you&#39;re probably more realistic here. If it were me I&#39;d break it out into at least 2 15 Amp circuits - not knowing anything at all about his situation other than what little was provided. At least then you could comfortably put something else on the circuit - like lights, a small fridge, network routers, fans for the room, a radio, creature comforts.

Electricians will thank you for the extra work but it is not necessary.

Hi, Typical computer power supply is ~400W rated. I can see any problem. CRT monitors consume quite a bit more than LCD panels.

According to the EPA, a typical desktop computer uses between 25 and

Source:

Source:

Source:

Source:

Cheers, Paul

Every bit of electrical equipment with a UL rating should have somewhere on it a plate that tell you what sort of power it draws.

Add them up.

Two desktop PCs. One Compaq Proliant 2500 server Two 21" CRTs One Laptop PC

... is too much for a 15 amp circuit. I guess people didn&#39;t use equipment like that back when wiring four rooms per circuit was okay.

I almost picked up a 5-node RS6000 on Ebay but I&#39;d have had to rewire the house to power it!

-rev

There should be very little startup surge, since there&#39;s no disks.

And power consumption will be higher than THAT. These things (power supplies) aren&#39;t 100% efficient.

A large CRT monitor can easily use more power than the computer itself. A good reason for turning the monitor off when you&#39;re not using it.

I have 3 computers on the same circuit. 2 have LCD monitors and the other monitor is off most of the time.

This same circuit is used part of the time to power about 5-8A of holiday lights.

Hi Mark,

I&#39;m sure some of the larger CRTs could consume in excess of 100-watts but more typical office-type CRTs are likely to come in below this. For example, the University of Waterloo tells us their 17" SONY CRTs draw 75-watts when in use.

Source:

Unless we&#39;re looking at some unusual setup, budgeting 30 to 60-watts for a 17 to 19-inch LCD panel and 75 to 125-watts for the equivalent CRT doesn&#39;t strike me as unreasonable.

As a sidebar to this, with the low cost of LCD panels, I can&#39;t imagine why anyone would want to buy a CRT monitor, unless they had a pretty compelling reason to do so. I can purchase a name brand 22-inch LCD monitor for under $400.00 Canadian (less than $340 US) and a 17-inch LCD monitor for half that. The energy savings and, in particular, the resulting space savings make this a no-brainer.

The other thing we shouldn&#39;t forget is that OP has told us these are thin clients about the size of a large book, so it&#39;s safe to assume their power consumption is quite low. We know, in fact, the Compaq t5720 has a maximum power draw of just 30-watts and that Sun&#39;s Sun Ray thin client is under 8-watts, or about the same amount of power as would be consumed by a night light.

So if we were to allocate 60-watts for an LCD monitor and 40-watts for a thin client PC, our total combined wattage for these three work stations is 300-watts (~ 2.5 amps) and that&#39;s being rather generous. And if CRT monitors are used in lieu of LCD panels, total wattage might then jump to between 350 and 450-watts (< 4 amps).

Cheers, Paul

Check the power ratings of the devices and add up the amperage.

If you are talking about something like the Sun Ray devices (

Simplest way to find out without guesstimating is to use a Kill-S- Watt, and _measure_ the actual va, watts, amps, whatever drawn by the combination of devices connected downstream from it. Clue: watts are not the limiting factor, since power-factor can vary widely; count amps.

Sure bet: nowhere near 20a draw.

HTH, J

Go wireless and forget about the circuit completely. That is what wireless means isn&#39;t it?

Why won&#39;t these d*mn systems boot up?

The printer should be a major consumer only when printing.

I was wondering how long this thread would get before someone suggested measuring the actual usage.

Maybe if you put 3 or 4 big CRT monitors on each computer.

If everything was completely wireless, there&#39;d still need to be a power source. I heard something about "power-over-RF" recently.