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From: "Ed Anderson" <eanderson@carolina.rr.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
References: <list-1488053@logan.com>
Subject: Injector Switches !!! was  Re: Powering fuel injectors
Date: Fri, 20 Oct 2006 08:57:56 -0400
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Hi Greg,

Looks like a good electrical system over all.      However, I would not feel 
comfortable with fuses in my critical system power line.  But, I see that 
you are routing two power sources to each switch of your critical system 
which means if one fuse blows due to a transit spike, the other one, 
hopefully, will not.  Again, this is my own personal bias against fuses in 
critical systems - there are arguments to the contrary for sure.

One thing I did notice, is looking at your injector power switches, I am not 
certain if these are meant to be the same as Tracy Crook's Injector disable 
switches.  If they are (and they may not be), I do not see the connection 
that automatically grounds the "cold Start" mode in the EC2 when either 
injector pair are disabled (turned off).

  This may be a detail just not shown on the drawing - but it is crucially 
important.  If the injector power switch does not have the "cold start" 
grounding provision, then if you ever switch off one of the injector pairs, 
your fuel flow will drop approx by 1/2 half.  The reason is that (with 
Tracy's recommended switch set up) when you turn off one pair of injectors 
, that automatically grounds the "cold start" pin  which causes the EC2 to 
double the duration of the PW (Pulse Width) signal to the remaining injector 
pair.  This in turn doubles the amount of fuel from the active pair of 
injectors.  If the "cold start" is not activated (by automatic grounding of 
the cold start pin through a DPDT switch) when an injector pair is switched 
off,  then the PW signal does NOT double and the fuel flow through the one 
injector pair will only be 1/2 of what the engine needs.


Ed

Ed Anderson
Rv-6A N494BW Rotary Powered
Matthews, NC
eanderson@carolina.rr.com
http://members.cox.net/rogersda/rotary/configs.htm#N494BW
http://www.dmack.net/mazda/index.html

----- Original Message ----- 
From: "Greg@itmack" <greg@itmack.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Friday, October 20, 2006 3:33 AM
Subject: [FlyRotary] Re: Powering fuel injectors


> I'm trying to keep the number of switched down as well,  I attached a pdf
> with my schematic which is a work in progress for your review.
>
> I have noted that a lot of builders reduce a lot of this complexity by 
> just
> hanging everything off 1 or 2 fuses which is fine until a fuse blows and
> then everything stops.
>
> Greg RV8 down under
>
>
>
>>I am using Z-19 from the Aeroelectric Connection as a guide for wiring
>> my plane.  I would like to power the injectors from the battery buss.
>> Looking at Z-19, do I need to install a complete switch and diode system
>> for the injectors like is done for the fuel pump and ECU, or can I tie
>> on to the fuel pump OR the ECU system after either the switch (add a
>> separate diode) or after one of the diodes?
>> There will be the two DPDT switches to disable the primary and secondary
>> injectors after this connection.
>> My panel is becoming somewhat switch festooned and I would like to keep
>> more switches to a minimum.
>> How have you guys accomplished this?
>>
>> Thanks.
>> Bill B
>>
>>
>> --
>> Homepage:  http://www.flyrotary.com/
>> Archive and UnSub:   http://mail.lancaironline.net/lists/flyrotary/
>>
>>
>


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