| Thanks Andrew
I have all those diagrams etc. Over the years I have built up a respect for Tracy and some others in this list for their thinking and keeping things simple.
Your opinion is pretty much in line with what I was thinking in regard to the Battery being a backup to the Alt. The Renesis alt was big and bulky so I replaced it with a small one and cant remember what it was out of. I'll do a load test once I've got all systems working. Why did you convert to external regulation? I thought the vehicle alternators were pretty clean and reliable?
What I am struggling with is: Modern auto electric systems just don't fail very often (Has any one here had a failure of basic circuit feeds?) Redundancy can introduce other failure modes or possible complexity in an emergency. When I trained twenty five years ago on the ILS system at Perth Airport, if my memory serves me right, the main reason for the system being down was the arbitrator failing, not the actual A and B systems. Hey I'm going to go with the experts like lectric Bob. Just want to KIS.
Questions: Is there a reliable modern replacement to the old, huge, heavy contactors? Redundancy of Fuel pumps (a given) Redundancy of Alternator (happy to manage the risk of losing it with voltage and current alarms) Redundancy of EFI/IGN (managed by EC2?) It seem to me to come back to the redundancy of the main battery system. So: Single Alternator, Battery system, Auto Key switch (replacing battery annually, clear current and voltage alarms). OR Single Alternator and dual Batteries (this then introduces (Z-19) 2 contactors, a diode and three switches.
Please have mercy on me, if I don't understand!
Cheers
Steve Izett
Steve Izett On 17/07/2012, at 2:21 PM, Andrew Martin wrote: Steve
Have you got a copy of Bob Nuckolls Book? Along with Tracy's diagrams in his ec2/3 manual you'll have all the infomation you require
What alternator are you using? I ended up using a 60 or 70 amp unit out of a subaru and converted it to external regulation as the 100amp unit that came with the renesis was going to be a real bugger to make work. cannot remember the details now but at the time it seemed like half the regulator was in the alt and half in the cars EC(which I didn't have).
My 2c opinion is that the Alternator is the main source of power, the battery is a backup. so battery should be sized to suit your desired Alternator off endurance, which will be specific to your aircrafts minimum electric power consumption. If your ever planing on flying east or up north from Perth I'd suggest to try for 3-4 hours battery endurance just to make sure you can safely make a landing area near civilization.
Andrew Martin
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