[Mobile-Portable] Paralleling wires for increased current capacity.

[DavidE Benedict]

***
Criteria is the key...

OK, when getting down to nitty-gritty, all of these wire-size vs. current
& voltage ratings have criteria based on such as insulation type, stranded
or solid, how many strands, voltage drop allowed, vibration factors,
application type (in conduit, what type conduit, in sheath, what type
sheath, in an approved cabinet, in transformers, bare, etc.) etc. 

In my previous post I was going by current-carrying capacity as stated by
National Electrical Code for Residential Wiring (pretty safe but not super
conservative).
-- Thinking a commonly available #10 wire is safe & practical (with regard
to voltage drop) at 30 Amps, then two #10's would comfortably carry 60
Amps, and be practically equivalent to a single #6 wire which is variously
rated at 60+ Amps. 

In NEC I think there used to be only even numbered wire sizes and their
ratings. 
It has been 35 years since I looked at it, but... 
eg., when you go to Home Depot I think you find only even wire sizes and
breaker "size"/currents based on them.
#14 uses a max 15 amp fuse/breaker
#12 uses a max 20 amp breaker
#10 uses a max 30 amp breaker
#8  uses a max 40-50? amp breaker 
(I'm hazy about #8 )
#6  uses a max 60 amp breaker
etc.

-- At any rate, for Ham purposes two household #10 stranded easily carry
60 Amps for short distances in a car (with 1/2 of the voltage drop of one
#10 in a given length/application), three 10's would be almost eq. to #4,
and, in practical application in a Ham's automobile, properly connected,
would be practically Eq. to a  typically available, rated, and branded #4
wire.

Considering the Ham/automobile applications, my desire for quality, low
voltage drops, and to be safe over time's degradations of things, I always
double what 'the book' indicates for current-carrying capacity. 

The book indicates a #10 for 30 amps? 
I would simply use 2 ea. #10's in parallel or a #6...at the very least, a
single #8...but feel a double #8 would be rediculous. 

David B.
W7DBH


> DavidE
>Benedict
>Subject: Re(2): [Mobile-Portable] What Gauge Wire?
>>
>>Question:  What is the result when one parallels two wires?
>>e.g. If one parallels two #10 wires is the result a current
>>handling capacity of #8 or #5 or ???
>
>
>****
>OK, if I am on the mark here, 
>#10  = 30 amp rating
>#6  = 60 amp rating.
>
>Paralleling 2 ea. #10's will be equivalent of a #6, and will be, as you
>probably know, typically lots easier to route past those tight zigs and
>zags...great idea!
>
>David B.
>W7DBH
>
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>----
>Your Moderator: Dick Flanagan K7VC, mobile-portable-owner at mailman.qth.net
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