dslreports logo
 
    All Forums Hot Topics Gallery
spc
Search similar:


uniqs
1574

whocares256
''Hardware Junkie''
Premium Member
join:2002-03-10
Motorola MB8600
Netgear SRX5308
EnGenius EAP1750H

2 edits

whocares256

Premium Member

Electrical Derating

Click for full size
Need Dedicated Outlets for my router and Laser Printer
I have a question for the electrical experts. I would like to have dedicated outlets in my office. I bought a spool of 12/3 w ground and would like to have the top outlet 1 20 amp circuit and the bottom another 20 amp circuit. I know I will need a 240 volt 20 amp breaker since these will be on the opposite side of the split phase wiring. What is the electrical derating requirements?

Edit: Spelling
Speedy Petey
join:2008-01-19

Speedy Petey

Member

De-rating requirements for what? Nothing you have explained so far would require any de-rating at all.

whocares256
''Hardware Junkie''
Premium Member
join:2002-03-10

whocares256

Premium Member

I was wanting to use 12/3 for a MWBC. 120v each side but if you put them to together you get 240. I was told if you have more than 2 current carrying conductors you have to derate.

Edit: Additional info.

John Galt6
Forward, March
Premium Member
join:2004-09-30
Happy Camp

John Galt6 to whocares256

Premium Member

to whocares256
That's a lot of switching power supplies on a shared neutral...if you load up the circuits, you could have a neutral burnout with a comcommitant equipment failure.

The preferred method is to provide a neutral for each phase. While the risk is low, it is not worth the "savings" to use shared neutrals in this environment.

whocares256
''Hardware Junkie''
Premium Member
join:2002-03-10
Motorola MB8600
Netgear SRX5308
EnGenius EAP1750H

whocares256

Premium Member

Click for full size
Main PC
Excluding the Laser printer, everything only pulls around 300 to 350 watts. Now my Main rig is on the other wall and I haven't put a Kill-a-Watt on it yet but it has a 1000VA UPS and the racks pictured above have a low end business APC 1500VA UPS. I would like to also have a dedicated outlet for my Main PC.
Speedy Petey
join:2008-01-19

Speedy Petey to whocares256

Member

to whocares256
Just so you know, the neutral only carries the current imbalance and therefore does not count towards derating.

whocares256
''Hardware Junkie''
Premium Member
join:2002-03-10
Motorola MB8600
Netgear SRX5308
EnGenius EAP1750H

whocares256

Premium Member

Yes, On a 240v circuit. I want to run wire and split the 240 in to 2 120v circuits basically a MWBC. If the neutral fails for what ever reason, then the voltage changes depending on the resistance of the devices attached to each side. one side can go to 160v and the other can go to 80v for example. Basically wired in series instead of parallel.

John Galt6
Forward, March
Premium Member
join:2004-09-30
Happy Camp

John Galt6 to whocares256

Premium Member

to whocares256
Neutral issue aside, the 12/3 is already 'derated'.

Feel free to use it if that is what you want to do...just make sure it is on a two-pole CB.

whocares256
''Hardware Junkie''
Premium Member
join:2002-03-10

whocares256

Premium Member

The wire I have is the Yellow NM-b 600v rated 12/3 w/ground is rated at 20 amps. Another question: How is this already derated? Anna, TX goes by the 2006 electrical code. AFCI's in All Living areas.

jrs8084
Premium Member
join:2002-03-02
Statesville, NC

jrs8084

Premium Member

Sorry for being OT, but do you know if those are Kewaunee Technical Furniture Group server racks?

whocares256
''Hardware Junkie''
Premium Member
join:2002-03-10
Motorola MB8600
Netgear SRX5308
EnGenius EAP1750H

whocares256

Premium Member

Click for full size
Power Meter and Breaker Box
Click for full size
Inside wall from Breaker Box
Click for full size
Main Breaker
Click for full size
All Other Breakers
Additionally any advice on how to run the wire from the breaker box to the attic?
whocares256

whocares256 to jrs8084

Premium Member

to jrs8084
jrs8084,

I can't be sure what brand the racks were. The labels were on the doors. I threw the doors and sides out so I could move the racks around more easily (weight issue). The racks were given to me from a friend of a friend who have a small private theater and he upgraded and got rid of the racks.

John Galt6
Forward, March
Premium Member
join:2004-09-30
Happy Camp

John Galt6 to whocares256

Premium Member

to whocares256
said by whocares256:

Another question: How is this already derated?

Too long of a discussion of technical issues...

As long as you put the 12/3 on a 20A two-pole CB, you're good to go.

whocares256
''Hardware Junkie''
Premium Member
join:2002-03-10
Motorola MB8600
Netgear SRX5308
EnGenius EAP1750H

whocares256

Premium Member

I have a questions for nunya, I have a couple of older style Cutler Hammer Breakers, These were bought from Lowes sometime in the Early 2000's. Will they fit in my Eaton Breaker Panel? I know Eaton bought out CH a while back. I have a CH120 and a CH115. I also have a Square D breaker but I'm pretty sure it will not fit. It is a Q0120.

nunya
LXI 483
MVM
join:2000-12-23
O Fallon, MO
·Charter

1 recommendation

nunya to whocares256

MVM

to whocares256
Running to the outdoor panel will be a PITA. So, I pose this question first: Why are we doing this project? Is there an actual need? Is the breaker tripping?
I have to be honest, a few years ago my server rack looked like yours. I decided to upgrade my equipment to reduce heat, noise, and power usage.

I would take the money you were going to spend on this little project and put it toward dispatching the antiquated equipment.

whocares256
''Hardware Junkie''
Premium Member
join:2002-03-10
Motorola MB8600
Netgear SRX5308
EnGenius EAP1750H

1 edit

whocares256

Premium Member

The main problem I have now is when I print the CFL in the room Flickers and the ups goes "Boing Boing" That is the AVR. So The printer needs to be on a separate circuit defiantly (brownout) . I prefer all my computers to be on their own circuit instead of the general house circuits that span several rooms. As far as the panel and moving it its just an Ideal now. I just don't like going outside to flip a breaker especially if the grass is wet..... If you look at my circuit panel I have 4 20 amp circuits (AFCI Breakers) through out the house (excluding the kitchen appliance circuits). I don't want to plug in the vacuum cleaner into the same circuit as all my computers. I already have add in boxes and the wire from other projects. This is a new house that was just built. The builders would not let me add any additional circuits while they were building it. This is the usual tract home subdivision.

Edit: Clarification
Speedy Petey
join:2008-01-19

Speedy Petey to whocares256

Member

to whocares256
said by whocares256:

I have a questions for nunya, I have a couple of older style Cutler Hammer Breakers, These were bought from Lowes sometime in the Early 2000's. Will they fit in my Eaton Breaker Panel? I know Eaton bought out CH a while back. I have a CH120 and a CH115. I also have a Square D breaker but I'm pretty sure it will not fit. It is a Q0120.

CH is CH. QO is QO. BR is BR.
Some limitations and quirks over the years, but a CH is a CH as far as you need to be concerned.