induced noise

M

Mike Riddell

Guest
Hello, I'm in the process of building a lab for my electronics and
computers. I plan on running three separate circuits: one for the
computers, one for my test equipment and one for general usage. I would
like to use 14/3 cable to run from the panel to the workbench areas but I am
concerned that there is the possibility of noise being induced into one of
the other circuits. The 14/3 would be the cleanest way of routing the wire
but running three separate wires would not be a problem either. Am I being
overly cautious or is this a valid concern? Your input would be greatly
appreciated.
 
You'll be fine, go ahead. Use 12/3 if you going to load to 20 amps.
hank wd5jfr
"Mike Riddell" <mriddell@sentex.ca> wrote in message
news:3fc0b382@news.sentex.net...
Hello, I'm in the process of building a lab for my electronics and
computers. I plan on running three separate circuits: one for the
computers, one for my test equipment and one for general usage. I would
like to use 14/3 cable to run from the panel to the workbench areas but I
am
concerned that there is the possibility of noise being induced into one of
the other circuits. The 14/3 would be the cleanest way of routing the
wire
but running three separate wires would not be a problem either. Am I
being
overly cautious or is this a valid concern? Your input would be greatly
appreciated.
Click to expand...
 
Mike posted:
Hello, I'm in the process of building a lab for my electronics and
computers. I plan on running three separate circuits: one for the
computers, one for my test equipment and one for general usage. I would
like to use 14/3 cable to run from the panel to the workbench areas but
I am concerned that there is the possibility of noise being induced into one
of
the other circuits. The 14/3 would be the cleanest way of routing the wire
but running three separate wires would not be a problem either. Am I being
overly cautious or is this a valid concern?
Click to expand...
You will be less likely to have noise if you use separate wires to bring in the
power.

You should use 14/3 "with ground." 12/3 with ground would be only a little
more expensive, and you would then have 20 Amp capability if you also use 20
Amp breakers. The ground wire provides a safety ground.

Also, if you want to have 220 (240) Volts available at the lab, be sure each of
the 110 connections at the breaker box ( Red & Black) is tied to a different
side of the incoming line. You will have 110V from Red to neutral (white), and
110V from Black to neutral, and 220V between Red and Black. A "220V" breaker,
due to how it is built, connects to the two different sides when it is seated
in the box.

Also, a GFCI would be a good idea for a lab. Mine operate on just a few
hundred millivolts. I've popped them off without feeling anything, so I know
they are a good thing to have.

Don

Don
 
On Sun, 23 Nov 2003 08:17:59 -0500, "Mike Riddell"
<mriddell@sentex.ca> wrote:

Hello, I'm in the process of building a lab for my electronics and
computers. I plan on running three separate circuits: one for the
computers, one for my test equipment and one for general usage. I would
like to use 14/3 cable to run from the panel to the workbench areas but I am
concerned that there is the possibility of noise being induced into one of
the other circuits. The 14/3 would be the cleanest way of routing the wire
but running three separate wires would not be a problem either. Am I being
overly cautious or is this a valid concern? Your input would be greatly
appreciated.
Click to expand...
As I read this, I suspect you are planning to run a _single_ 14/3
cable which will carry all three circuits - this is neither legal or
possible, as you need hot, neutral, and safety ground wires for _each_
circuit.

According to my knowledge of the Canadian Electrical Code, you must
use three separate 14/2 cables, if the circuits are fed by 15 amp
breakers, or 12/2 if you have 20 amp breakers. A 14/2 or 12/2 cable
will actually have three conductors: black (hot), white (neutral) and
uninsulated (safety ground).

If two of the circuits are on opposite 120V phases, you could combine
them into one 14/3 or 12/3 cable, sharing the neutral.

--
Peter Bennett, VE7CEI
new newsgroup users info : http://vancouver-webpages.com/nnq
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca
 
"Mike Riddell" <mriddell@sentex.ca> wrote in message
news:3fc0b382@news.sentex.net...
Hello, I'm in the process of building a lab for my electronics and
computers. I plan on running three separate circuits: one for the
computers, one for my test equipment and one for general usage. I would
like to use 14/3 cable to run from the panel to the workbench areas but I
am
concerned that there is the possibility of noise being induced into one of
the other circuits. The 14/3 would be the cleanest way of routing the
wire
but running three separate wires would not be a problem either. Am I
being
overly cautious or is this a valid concern? Your input would be greatly
appreciated.

Mike,
Click to expand...

You ARE aware that there are filtered power feeds, right?
Corcom comes to mind....but there are others.
If you properly install a good filter on all three drops,
you should not couple any noise from one circuit to another.


--
*
| __O Thomas C. Sefranek WA1RHP@ARRL.net
|_-\<,_ Amateur Radio Operator: WA1RHP
(*)/ (*) Bicycle mobile on 145.41, 448.625 MHz

http://hamradio.cmcorp.com/inventory/Inventory.html
http://www.harvardrepeater.org
 
dbowey's post included:
"You will be less likely to have noise if you use separate wires to bring in
the
power."

--

That IS NOT what I intened to say. You will be less likely to have noise if
you use cable (14/3 or 12/3 with ground) to bring in the power.

Sorry about that..

Don
 
On Sun, 23 Nov 2003 08:17:59 -0500, "Mike Riddell"
<mriddell@sentex.ca> wrote:

Hello, I'm in the process of building a lab for my electronics and
computers. I plan on running three separate circuits: one for the
computers, one for my test equipment and one for general usage. I would
like to use 14/3 cable to run from the panel to the workbench areas but I am
concerned that there is the possibility of noise being induced into one of
the other circuits. The 14/3 would be the cleanest way of routing the wire
but running three separate wires would not be a problem either. Am I being
overly cautious or is this a valid concern? Your input would be greatly
appreciated.
Click to expand...
Ac power is noisy; there's no point in separating circuits.

John
 
"Mike Riddell" <mriddell@sentex.ca> wrote in message
news:3fc0b382@news.sentex.net...
Hello, I'm in the process of building a lab for my electronics and
computers. I plan on running three separate circuits: one for the
computers, one for my test equipment and one for general usage. I would
like to use 14/3 cable to run from the panel to the workbench areas but I
am
concerned that there is the possibility of noise being induced into one of
the other circuits. The 14/3 would be the cleanest way of routing the
wire
but running three separate wires would not be a problem either. Am I
being
overly cautious or is this a valid concern? Your input would be greatly
appreciated.


If you are worried about electrical noise, just install a good UPS...No
Click to expand...
matter how you wire it....what comes off the pole is not always
clean.....Ross
 
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