Dave, Tracy is right.  Lean it, live it.   :-)

 

But to expand a little,  I used 18G wire for the injectors and coils, so a 10 amp breaker/fuse was appropriate.  I did exactly what you describe.  It is OK to put 2, 18G wires on the same 10A fuse if the curent draw of the device is low enough and you don't mind losing both devices if one goes.  This is actually preferable with the injectors (if you loose one secondary injector, it is preferable to loose the other as well to make compensation easier).  This is not the case with the coils (would prefer to not loose the other leading coil), but it is not particularly deliterious either.

 

10A was big ennough for my system, but for an extra margin of safety, you should consider using larger wire and fuses for the coils.  10A is probably the minimum there to be running 2 coils.
 

Dave Leonard
 

On 10/16/06, Tracy Crook <lors01@msn.com> wrote:

Answer to this one is always the same :  Size the breaker to protect the wire size used.  The device hooked to the wire has nothing to do with breaker size.

 

The 40 amp breaker example in the installation guide was to illustrate the importance of having separate main branches of the electrical system, one for flight critical systems and one for other stuff.  I got a call last week from a builder who lost his engine on final on his first flight when he turned on his landing lights.  Don't let this happen to you. 

 

To reiterate more explicitly,  Do NOT size the circuit breakers according to the amp load of the devices hooked to them.

 

Tracy

----- Original Message -----

From: David Staten

To: Rotary motors in aircraft

Sent: Monday, October 16, 2006 5:37 AM

Subject: [FlyRotary] What size CB or fuses.. EC 2 items..

 

After reviewing the electronic copy of the EC-2 manual I am at a loss
for an explicit answer.

What size fuse or CB is appropriate for the injectors.. and for the
coils (using LS-1 coils and I'm presuming that injectors are
"Standardized" to either low impedence or high impedance).. I already
have the resistors for my low impedance coils.

I intend to run one pair of injector power wires through one CB and the
other pair through another CB just for grins/giggles and I am
contemplating doing the same with coils as well...(trailing and leading
power leads)..So.. I am actually asking what size CB for 2 coils and for
2 injectors, respectively.. The manual simply says everything in Tracy's
plane (FP, coils, injectors) goes through one big 40 amp breaker...

Dave

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