---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Wed 07/10/13: 5 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:30 AM - Re: Low voltage indicator with dual alternators (Bill Watson) 2. 08:38 AM - Re: Low voltage indicator with dual alternators (Dave Saylor) 3. 09:53 AM - Re: Low voltage indicator with dual alternators (Bill Watson) 4. 11:12 AM - Re: Low voltage indicator with dual alternators (Tcwtech) 5. 12:03 PM - Footwell got burned! (rparigoris) ________________________________ Message 1 _____________________________________ Time: 07:30:49 AM PST US From: Bill Watson Subject: Re: AeroElectric-List: Low voltage indicator with dual alternators On 7/8/2013 4:29 PM, Robert L. Nuckolls, III wrote: >> My operational goals for the Z-14 included being able to run much of >> the panel >> on one battery while still having a fully charged battery for >> starting. The >> idea being that I wanted to be able to enter flight plans and even >> check weather >> before engine start. That's worked out well. I can connect the >> buses for starts >> if needed and that works well as well. > > Okay, but consider the ENERGY needed to do these two tasks. > Suppose you turn on three electro-whizzies for a total drain > of 3A */(a lot for solid state gizmos)/* and take 5 minutes to > herd all the ducks into place. That 12v x 3A x 300 seconds > for a total of 11,000 watt-seconds. > > Now, lets crank the engine at 200A x 12v x 10 seconds > for a total of 24,000 watt-seconds. > > How much energy is available for use in a 18 a.h. > SVLA battery? At a 3A rate will give it up over 5 hours > at an average voltage of 11.5 for a total of about 650,000 > watt-seconds. > > In other words, the task of conducting pre-flight activities > and starting the engine are not big demands on a well > maintained battery. That was my assumption going in. My original thought was that I'd be able to turn everything on, do my flight plan input, clearance copy and whatever, then turn the key and start her up. Thinking there would be little need to manage energy through th pre-start, I do not have an avionics master or bus or even power switches on my MFDs. The fly in the ointment has been tendency for the MFDs (3 GRT HX units) to reboot during an interconnected start. The energy draw is probably a bit more than one might expect but I don't have actual current draw measurements to validate. For planning purposes I assumed 4.5A for the 3 MFDs combined, 1A for the dual AHRS, .6A for ADSB weather, 2.1A for the G430. Add 1 amp for the contactor and (unknown) for the panel fans. That's 12v x 8.2A x 300secs = 29,520 watt-secs. That doesn't include the AP and audio panel which are on the same bus and are turned off at shutdown. It is the minimum I want for pre-start duck herding but I'm thinking I need to find a way to mitigate it. (BTW, Thanks so much for engaging me on this - This has become a big task on my improvement list for the year) > >> >> However, I normally start with the buses separated because if I go >> parallel, the voltage drop causes my 3 MDFs to re-boot. > > How much 'stuff' do you have to turn on before engine > start? On the Beech products we used to offer a mini-ebus > switch that would let you fire up a comm radio directly > from the battery. Your comm radio probably needs 0.2A receive, > and maybe 1.5A transmit. A long winded pre-flight activity > might need 1000 watt-seconds. How much? I need at least one MFD (weather, input of pre-flight values), the G430 (flight plan input & comm). But powering up only 1 MFD is a compromise - 3 are configured. With anything less, many error msgs are generated. Is all this pre-start duck herding necessary or desirable? Yes and Yes Virtually 99% of my flying is IFR. Single pilot in and out of the NY/PHL/WASH axis requires lining them up and knocking them down or getting called on every miss. The reality is more nuanced however. In winter, I start it, then begin the flight planning/clearance getting process. No electron problems except that the MFDs sometimes reboot on an interconnected cold weather start. In summer, temperatures demand minimizing the time with the RV10 gull wing doors closed. We're very comfortable sitting in the cockpit fooling around as long as a breeze is blowing thru with the doors providing some shade. Engine start requires the doors be closed and from that point on, it's sweaty and miserable until takeoff despite the strong stream of 'fresh' air blowing on our sun baked carcasses. The net is - I will hurry and/or skip some pre-flight, post-start planning activities until airborne and I invariably pay for that. Actually, I just don't let that happen any longer. > > I'm thinking that the bus from which all your 'kitchen > sink' accessories is powered also powers the comm radio > and you have no way to power up the comm radio independently? > You might want to consider moving a comm radio to a > battery bus and adding . . . > > COMM RADIO . . . . . Check OFF > > . . . . to your shutdown checklist. Done. The SL30 is on the other bus and other non-essential stuff is shut down during shut down, but the whole G430 needs to be online for flight planning. I don't consider it a kitchen sink - just the essentials in this bit intensive world. It just occured to me that several non-bus essentials aren't even included; the cell phone for remote IMC releases and the iPad. Most NY/WASH/PHL clearances, make that 'all' such clearances, require victor airway translation for G430 input. Entry of the 8-10 step clearance into the iPad is required in order to figure out that actual waypoints for entry into the G430. It's usually desirable to make sure I 'get it' before taking off over NYC and heading toward the Wash SFRA, which means that it then gets mostly input into the G430 before engine start. Ah, the joys of the paper-less cockpit! > > Bottom line is that with two batteries on board, you've > got perhaps a million watt-seconds to burn. Doing your > starts in parallel will reduce relative abuse to the batteries > and extend their service life. Letting the 'kitchen sink' > accessories clock in after engine start may not be > a significant delay in your departure plans. > Well, in summer I need the essential sink before start. Point well taken, but no doubt about the need here. However, I'd like to get back to interconnected parallel starts with all my essential stuff on. I'm thinking the core problem is not the load involved but rather the tendency for the GRT MFDs to re-boot. I started looking at power wiring options for the GRTs. This paragraph from the installation guide may be useful: The majority of the current flow into the display unit will occur on the bus with the highest voltage. So if the voltage of the main bus or power source falls below that of the secondary bus or power supply, the secondary bus will power the display units and operation will not be interrupted. Since it is desirable to not have the display units and AHRS connected to the power supply supplying power to the engine starter during the engine start (to maximize the current available for the starter, and possibly extend the life of the CCFL backlight in the display unit), this feature allows the fitting of a small (3-5AH) auxiliary battery to one of the power input connections provide power to the EFIS during engine start. If an auxiliary battery is fitted, provisions should be made to keep it charged. What do you think? ________________________________ Message 2 _____________________________________ Time: 08:38:29 AM PST US From: Dave Saylor Subject: Re: AeroElectric-List: Low voltage indicator with dual alternators (3-5AH) auxiliary battery to one of the power input connections provide power to the EFIS during engine start. If an auxiliary battery is fitted, provisions should be made to keep it charged. My GPS/Comm used to reboot on engine start. It was a pain to wait for it to reboot and find sats again. I put it on a TCW backup battery and it stays on during the start now. How nice. On a non-electric point--not to start a primer war, but--I leave my -10 doors open during taxi if it's hot out. It's one of the things I love about the design. Dave Saylor 831-750-0284 CL ________________________________ Message 3 _____________________________________ Time: 09:53:17 AM PST US From: Bill Watson Subject: Re: AeroElectric-List: Low voltage indicator with dual alternators Wow! The TCW product seems perfect for the GRT issue. Was unaware of it. Thanks. I'm not sure I have the ba...., I mean constitution to taxi about with the doors open. But I'm going to think about it. I certainly leave them open in brisk winds and such. I've also cracked it and held on to it during taxi but I'd never have a passenger do that. But wide open 'eh? At home, my field is rough and I'm having trouble imagining them bouncing around. On hard top... I can see it but... Do you limit your door open ops in any way? On 7/10/2013 11:33 AM, Dave Saylor wrote: > > (3-5AH) auxiliary battery to one of the > power input connections provide power to the EFIS during engine > start. If an > auxiliary battery is fitted, provisions should be made to keep it > charged. > > > My GPS/Comm used to reboot on engine start. It was a pain to wait for > it to reboot and find sats again. I put it on a TCW backup battery > and it stays on during the start now. How nice. > > On a non-electric point--not to start a primer war, but--I leave my > -10 doors open during taxi if it's hot out. It's one of the things I > love about the design. > > Dave Saylor > 831-750-0284 CL > > * > > > * > > No virus found in this message. > Checked by AVG - www.avg.com > ________________________________ Message 4 _____________________________________ Time: 11:12:00 AM PST US Subject: Re: AeroElectric-List: Low voltage indicator with dual alternators From: Tcwtech Our IBBS product line provides back-up power to devices like efis equipment a s well as GPS and comm systems. One of the added benefits is that during en gine cranking the auto transfer circuitry knows to keep the connected load f rom dropping out and resetting. Connecting our IBBS product to the GRT s ystem is very straight forward and 1/2 the weight of adding another similar s ized lead acid battery. Also, if you don't need the full feature of back-up power and just want to r esolve the issues with system resets during engine cranking, our IPS systems provide consistent, stable voltage to the connected load(s) with a maintena nce free solution. All the details are on our web site and can be seen at our booth at Oshkosh. Www.Tcwtech.com Bob Newman. Sent from my iPhone On Jul 10, 2013, at 10:52 AM, Bill Watson wrote: > Wow! The TCW product seems perfect for the GRT issue. Was unaware of it . Thanks. > > I'm not sure I have the ba...., I mean constitution to taxi about with the doors open. But I'm going to think about it. > > I certainly leave them open in brisk winds and such. I've also cracked i t and held on to it during taxi but I'd never have a passenger do that. But wide open 'eh? > > At home, my field is rough and I'm having trouble imagining them bouncing a round. On hard top... I can see it but... > > Do you limit your door open ops in any way? > > On 7/10/2013 11:33 AM, Dave Saylor wrote: >> (3-5AH) auxiliary battery to one of the >> power input connections provide power to the EFIS during engine start. If an >> auxiliary battery is fitted, provisions should be made to kee p it charged. >> >> My GPS/Comm used to reboot on engine start. It was a pain to wait for it to reboot and find sats again. I put it on a TCW backup battery and it sta ys on during the start now. How nice. >> >> On a non-electric point--not to start a primer war, but--I leave my -10 d oors open during taxi if it's hot out. It's one of the things I love about t he design. >> >> Dave Saylor >> 831-750-0284 CL >> >> >> >> >> No virus found in this message. >> Checked by AVG - www.avg.com >> 07/10/13 >> > > > ========================== ========= ========================== ========= ========================== ========= ========================== ========= > ________________________________ Message 5 _____________________________________ Time: 12:03:37 PM PST US Subject: AeroElectric-List: Footwell got burned! From: "rparigoris" Hi Group I accidentally burned my starboard foot-well! I replaced my lanterns alkaline battery (EverReady) ~ Christmas 2010. It hasn't seen any use since then. I sit down in front of my Europa XS Mono to study the undercarriage mounting frame, need some light. No problem, I grab my lantern that I always store with the lens up (in case it is left on), turn it on and use it for 5 or so minutes. I turn it off and rest it on my starboard foot-well, again with the lens up. After about 10 minutes I pick it up, turn it on to use it again and see what I think is water on my foot-well, it's turning the Phenolic resin black! I'm not sure just what leaked out of the battery, but it was water clear and had the viscosity of 3 in 1 oil. I was able to get off perhaps 1/2 of the damage, I tried water, alcohol and acetone with scotch-bright. Anyway the resin sure did react quick to whatever it was that leaked out.: https://skydrive.live.com/redir?resid=550FC20DBDDB521D!1656&authkey=!AEWLOllC2BXrnI0 Ron Parigoris Read this topic online here: http://forums.matronics.com/viewtopic.php?p=404405#404405 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.