Subject: Wire or Amps?
From: Rotary Engine
Date: 7/19/2010, 9:28 AM
To: AAA Put this in the To box


Can you tell me what size wire I need, or how many amps the solenoid
for a
Mazda starter draws?



Sandy McNabb

Renesis in a Glass Goose

As near as I can tell the the resistance of the solonoid is
about .8 ohm.

So the current will be about 15 AMPs. At 12 volts. V/R = A
http://www.powerstream.com/Wire_Size.htm

Lookslike about 10 gage stranded wire.

Paul Lamar


10 gauge is way overkill for a solenoid, which is intermittently
used.The chart is for NEC code, which is continuous loading,
which relies on max bundle size for wiring. Hence 14 gauge
for 15 amp breakers (lighting loads) and 12 gauge for wall
sockets (20 Amp breakers).

14 gauge would be sufficient for solenoid use.I would be
surprised if Mazda used anything larger.

Bob Knuckles, Aeroelectric, puts out a pretty good book
on aircraft wiring that I would recommend.

Tom W

-----------------------------------------------

Tom W,

I learned how to use my multi-meter to measure amps. The starter
solenoid draws 8.14 amps so I'm considering an 18 AWG wire with a
10 amp fuse....or should I go higher?

Sandy McNabb
Renesis in a Glass Goose

Sandy, what are you gaining by using smaller wire?

What you lose is a tiny bit of power to the solenoid.

Starters are around 3 HP so 190 amps so the solenoid
current is minuscule by comparison.

Paul Lamar


Is this wire kust to activate the solonoid, or carry the current
to the Starter motor ? Virg

Just to activate the solonoid.

Paul Lamar
-- 
The Rotary Engine NewsLetter. Powered by Linux.
ACRE NL web site. http://www.rotaryeng.net
Youtube key word PaulLamar2
Copyright 1998-2010 All world wide rights reserved.