RECEPTACLES FOR COMPUTERS

[jackcarman]

IN A SCHOOL, HOW MANY STUDENT COMPUTERS CAN I PUT ON ONE 20 AMP CIRCUIT AND BE IN COMPLIANCE WITH THE NEC AND ACCOUNT FOR HARMONICS. THE COMPUTERS ARE SMALL CRT TYPE WITH NO NAMEPLATE DATA. THEY ARE CONNECTED TO A NETWORK AND HAVE NO ACCESSORIES. THE SCHOOL DISTRICT WANTS A MAXIMUM NUMBER OF COMPUTERS ON EACH CIRCUIT TO CUT POWER DISTRIBUTION SYSTEM COSTS, AND THEY WANT US TO PUT AS MANY AS 10 COMPUTERS ON EACH CIRCUIT.

 

[hbiss]

Re: RECEPTACLES FOR COMPUTERS

I don't understand why there is no nameplate data. What kind of school district buys unlisted equipment? Anyway, get out your amprobe or whatever you have and see what the draw is. Keep the load under 80% (16 amps) per 20 amp circuit.

-Hal

 

[dereckbc]

Re: RECEPTACLES FOR COMPUTERS

First turn off the CAPS. It gives us the impression you are shouting.

No way to answer your question without knowing how much current or VA the units are pulling. I can tell you 10 is too many IMO. 8 would be a stretch, 6 would be about right assumming 250 Watt PSU, hard to say without facts.

Forget about harmonics. You cannot control harmonics on a school budget. It would require you to order PC with power factor correcting power supplies, or using special isolation transformer with dedicated branch circuits and oversized neutrals.

[ July 09, 2004, 01:57 PM: Message edited by: dereckbc ]