X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 10 [X] Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 26 Mar 2007 14:10:48 -0400 Message-ID: X-Original-Return-Path: Received: from wind.imbris.com ([216.18.130.7] verified) by logan.com (CommuniGate Pro SMTP 5.1.7) with ESMTPS id 1943990 for lml@lancaironline.net; Mon, 26 Mar 2007 13:55:16 -0400 Received-SPF: none receiver=logan.com; client-ip=216.18.130.7; envelope-from=brent@regandesigns.com Received: from [192.168.1.138] (wireless-135-19.imbris.com [216.18.135.19]) (authenticated bits=0) by wind.imbris.com (8.12.11/8.12.11.S) with ESMTP id l2QHsCOB079136 for ; Mon, 26 Mar 2007 10:54:28 -0700 (PDT) (envelope-from brent@regandesigns.com) X-Original-Message-ID: <460808C3.9080200@regandesigns.com> X-Original-Date: Mon, 26 Mar 2007 10:54:11 -0700 From: Brent Regan User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.2) Gecko/20040804 Netscape/7.2 (ax) X-Accept-Language: en-us, en MIME-Version: 1.0 X-Original-To: Lancair Mailing List Subject: RE: Bateries, weight & electrical systems Content-Type: multipart/alternative; boundary="------------020006000407090504050804" This is a multi-part message in MIME format. --------------020006000407090504050804 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit So many questions from Rick. I cannot address ES or Continental specific questions as I am unfamiliar with both. There are many pounds of weight that can be saved firewall forward. Lycomings are generally considered heavier then Continentals because the bare engine is heavier, yet my installation weight (twin turbo, dual intercoolers, automatic waste gate, dual alternator, oil) measured out at 611 lbs, 13 lbs lighter that a comparable TSIO 550 configuration. Replacing the AN365 nuts and AN960 washers with MS21042 nuts and AN960PD (aluminum) washers saves several pounds. Replacing the AN steel bolts with NAS-640x titanium bolts saves even more. Removing unnecessary (to flight) lifting brackets saves weight. Replacing heavy rubber flex hoses with stainless or aluminum hard line with aluminum B nuts saves a lot of weight. If you are really warped (like me) you will make titanium seal belt attachments and buckles and titanium door hinges. Don't get too carried away. Don't use aluminum AN fittings on the engine. Don't use hard line where a flex line is required. Don't use aluminum washers near the exhaust system. The most common electrical installed item to fail is the keyed ignition switch. I used the Nuckolls' approach with two 3 position magneto switches and a starter button. There is also a hidden switch that disables the starter for security. I don't recall ever seeing a jet that uses a key to start the engines. If thieves are determined enough to get past the door lock, an aircraft ignition switch is a trivial nuisance. Some answers to Rick's questions below. Circuit List posted on a separate email. <<<< Since a IV is theoretically similar to an ES electrically, I am very interested in your electrical system/suggestions - can you post/send a schematic? Circuit List posted. A schematic only shows interconnections, not the implementation details which are frequently as, or more, significant. Do you have a single/common ground bus? Any special precautions with it (as a single point of failure)? Yes, at the firewall penetration. It is a 3/8" brass bar with a copper plate that has 60 ground screws. <> How is your backup alternator and battery connected to the ships electrical systems? Through the cross-tie? Only? Diode and cross tie. Is your backup alternator a B&C SD-20? Or equivalent? Yes. Have you segregated your "essential" electrical equipment (i.e. a separate E-bus) to easily/effortlessly configure your system for low power draw (aka < 20 amps) in the event of a primary alternator (or regulator) failure? Yes. How do you turn on the essential bus and/or turn off everything else? Essential Bus switch ON, Main Buss switch OFF Are there any single points of failure in the essential bus and/or it's feed(s)? Only the ground penetration mentioned above. What equipment is on your essential bus (if you have one)? See Circuit list posted separately. What is your essential bus maximum current draw? 9.54 Amps (measured) What is your overall maximum current draw (everything on)? 63.75 Amps (measured) includes HPU and Door Seal Pump Do you have seat heaters? Front and back? No. Seat heaters, CD players, air conditioning, etc. are luxury items that deal with occasional / transient discomforts yet they must be carried all the time. I would rather have the luxury of going faster, something I enjoy every flight all the time. What is your typical continuous draw (with most normal/continuous things on - like pitot heat, lights, etc. See Circuit list. <>What is your strategy/timing for replacing your batteries (every 2-3 years)? Yes, on time. Do you have a load based AH battery test apparatus/procedure? <> No. Better to replace on time. There are failure modes a load test won't discover. When starting, do you typically have other electrical equipment on? EFIS? Engine Mon? GPS? Beakon? Cabin/Panel Lights? Yes, everything (Main Buss) on. Have you every had a starting brownout and/or starting spike failure? No. Do you believe in them? <>Yes, I believe some equipment is sensitive to brown outs and some electrical systems are poorly designed. I did not select sensitive equipment and have a 28V system with low impedance connections to the battery. Also the system is implemented such that the IR losses (amps times resistance = voltage drop) during starting are contained in the starting circuit and not reflected in the Main Buss (other than the battery internal resistance and terminal resistances). I designed full clamping battery terminal terminations to reduce losses. Have you ever had issues trying to start with a very cold battery (i.e. -10F)? No, Started fine at -15F in Denver. B&C Starter. What compression is your engine? 8.5:1. Yes it is turbocharged. Maximum manifold pressure at 2,700 RPM is 35 In Hg, producing 360 Hp (SAE corrected) on Monty Barrett's dyno. >>>>>>> Regards Brent Regan --------------020006000407090504050804 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit So many questions from Rick.

I cannot address ES or Continental specific questions as I am unfamiliar with both.

There are many pounds of weight that can be saved firewall forward. Lycomings are generally considered heavier then Continentals because the bare engine is heavier, yet my installation weight  (twin turbo, dual intercoolers, automatic waste gate, dual alternator, oil) measured out at 611 lbs, 13 lbs lighter that a comparable TSIO 550 configuration.

Replacing the AN365 nuts and AN960 washers with MS21042 nuts and AN960PD (aluminum) washers saves several pounds. Replacing the AN steel bolts with NAS-640x titanium bolts saves even more. Removing unnecessary (to flight) lifting brackets saves weight. Replacing heavy rubber flex hoses with stainless or aluminum hard line with aluminum B nuts saves a lot of weight. If you are really warped (like me) you will make titanium seal belt attachments and buckles and titanium door hinges.

Don't get too carried away. Don't use aluminum AN fittings on the engine. Don't use hard line where a flex line is required. Don't use aluminum washers near the exhaust system.

The most common electrical installed item to fail is the keyed ignition switch.  I used the Nuckolls' approach with two 3 position magneto switches and a starter button. There is also a hidden switch that disables the starter for security. I don't recall ever seeing a jet that uses a key to start the engines. If thieves are determined enough to get past the door lock, an aircraft ignition switch is a trivial nuisance.

Some answers to Rick's questions below. Circuit List posted on a separate email.
<<<<

Since a IV is theoretically similar to an ES electrically, I am very interested in your electrical system/suggestions - can you post/send a schematic?

Circuit List posted. A schematic only shows interconnections, not the implementation details which are frequently as, or more, significant.

Do you have a single/common ground bus? Any special precautions with it (as a single point of failure)?

Yes, at the firewall penetration. It is a 3/8" brass bar with a copper plate that has 60 ground screws.
<>
How is your backup alternator and battery connected to the ships electrical systems? Through the cross-tie?  Only?

Diode and cross tie.

Is your backup alternator a B&C SD-20?  Or equivalent?

Yes.

Have you segregated your “essential” electrical equipment (i.e. a separate E-bus) to easily/effortlessly configure your system for low power draw (aka < 20 amps) in the event of a primary alternator (or regulator) failure?

Yes.

How do you turn on the essential bus and/or turn off everything else?

Essential Bus switch ON, Main Buss switch OFF

Are there any single points of failure in the essential bus and/or it’s feed(s)?

Only the ground penetration mentioned above.

What equipment is on your essential bus (if you have one)?

See Circuit list posted separately.

What is your essential bus maximum current draw?

9.54 Amps (measured)

What is your overall maximum current draw (everything on)?

63.75 Amps (measured) includes HPU and Door Seal Pump

Do you have seat heaters?  Front and back?

No.  Seat heaters, CD players, air conditioning, etc. are luxury items that deal with occasional / transient discomforts yet they must be carried all the time. I would rather have the luxury of going faster, something I enjoy every flight all the time.

What is your typical continuous draw (with most normal/continuous things on – like pitot heat, lights, etc.

See Circuit list.

  <>What is your strategy/timing for replacing your batteries (every 2-3 years)?

  Yes, on time.

Do you have a load based AH battery test apparatus/procedure?

<> No.  Better to replace on time. There are failure modes a load test won't discover.

When starting, do you typically have other electrical equipment on?  EFIS?  Engine Mon?  GPS?  Beakon?  Cabin/Panel Lights?

Yes, everything (Main Buss) on.

Have you every had a starting brownout and/or starting spike failure?

No.

  Do you believe in them?

<>Yes, I believe some equipment is sensitive to brown outs and some electrical systems are poorly designed.  I did not select sensitive equipment and have a 28V system with low impedance connections to the battery. Also the system is implemented such that the IR losses (amps times resistance = voltage drop) during starting are contained in the starting circuit and not reflected in the Main Buss (other than the battery internal resistance and terminal resistances). I designed full clamping battery terminal terminations to reduce losses.

  Have you ever had issues trying to start with a very cold battery (i.e. -10F)?

No, Started fine at -15F in Denver. B&C Starter.

What compression is your engine?

8.5:1. Yes it is turbocharged. Maximum manifold pressure at 2,700 RPM is 35 In Hg, producing 360 Hp (SAE corrected) on Monty Barrett's dyno.
>>>>>>>

Regards
Brent Regan
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