---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sun 01/13/19: 22 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 03:29 AM - Basic Elec. Diagram -critique pls (supik) 2. 04:17 AM - Re: Basic Elec. Diagram -critique pls (Art Zemon) 3. 06:39 AM - Re: Basic Elec. Diagram -critique pls (Kelly McMullen) 4. 10:56 AM - Re: Basic Elec. Diagram -critique pls (Robert L. Nuckolls, III) 5. 10:56 AM - Re: Basic Elec. Diagram -critique pls (Robert L. Nuckolls, III) 6. 11:57 AM - Re: Basic Elec. Diagram -critique pls (supik) 7. 12:04 PM - Re: Re: Basic Elec. Diagram -critique pls (Kelly McMullen) 8. 12:16 PM - Re: Basic Elec. Diagram -critique pls (supik) 9. 12:30 PM - Re: Basic Elec. Diagram -critique pls (supik) 10. 01:21 PM - Re: Basic Elec. Diagram -critique pls (supik) 11. 02:17 PM - Re: Basic Elec. Diagram -critique pls (supik) 12. 03:23 PM - Re: Re: Basic Elec. Diagram -critique pls (Art Zemon) 13. 04:19 PM - Re: Basic Elec. Diagram -critique pls (supik) 14. 04:33 PM - Re: Basic Elec. Diagram -critique pls (supik) 15. 06:53 PM - Re: Re: Basic Elec. Diagram -critique pls (Kelly McMullen) 16. 07:13 PM - Re: Re: Basic Elec. Diagram -critique pls (Art Zemon) 17. 07:31 PM - Re: Re: Basic Elec. Diagram -critique pls (Charlie England) 18. 07:34 PM - Re: Re: Basic Elec. Diagram -critique pls (Kelly McMullen) 19. 08:02 PM - Internally Regulated Over Voltage Protection (BMC_Dave) 20. 09:01 PM - Re: Internally Regulated Over Voltage Protection (BMC_Dave) 21. 09:39 PM - Re: Re: Basic Elec. Diagram -critique pls (Rick Beebe) 22. 10:19 PM - Re: Re: Basic Elec. Diagram -critique pls (Sebastien) ________________________________ Message 1 _____________________________________ Time: 03:29:49 AM PST US Subject: AeroElectric-List: Basic Elec. Diagram -critique pls From: "supik" (I have posted this on VAF as well) This is my preliminary diagram for my RV-10 Single battery, dual alternator setup. (60amp B&C + 30amp B&C) Backup & Master switches ON during normal ops. Both alternators will be ON during normal ops. ALT-1 (60amp) regulator preset at 14.4V ALT-2 (30amp) regulator preset at 13.8V Both regulators are L3C-14 LV lights from regulators NOT utilized. Respective BUS voltages monitored by G3X Touch. -MAIN BUS threshold monitoring at or below 13.8V triggers (MASTER CAUT) MAIN BUS LV -ESS BUS threshold monitoring at or below 13.0V triggers (MASTER WARN) ESS BUS LV I hope this is possible to setup with the G3X Touch, expert opinion is welcomed. Shall the ESS-BUS relay fail, ESS-BUS alternate feed is provided by a diode. -------- Igor RV10 in progress Read this topic online here: http://forums.matronics.com/viewtopic.php?p=486919#486919 Attachments: http://forums.matronics.com//files/om_ela_basic_elec_diagram_v005_minor_txt_changes_144.jpg ________________________________ Message 2 _____________________________________ Time: 04:17:06 AM PST US From: Art Zemon Subject: Re: AeroElectric-List: Basic Elec. Diagram -critique pls Igor, What are you going to connect to your essential bus? Do you need it at all? I started with a wiring scheme like you have and eliminated the ebus when I realized that, in case of a primary alternator failure, I could simply turn off the pitot heat and landing lights. That reduces the current draw below 30A. -- Art Z. On Sun, Jan 13, 2019 at 5:45 AM supik wrote: > > (I have posted this on VAF as well) > > This is my preliminary diagram for my RV-10 > > Single battery, dual alternator setup. (60amp B&C + 30amp B&C) > Backup & Master switches ON during normal ops. > > Both alternators will be ON during normal ops. > ALT-1 (60amp) regulator preset at 14.4V > ALT-2 (30amp) regulator preset at 13.8V > > Both regulators are L3C-14 > LV lights from regulators NOT utilized. Respective BUS voltages monitored > by G3X Touch. > -MAIN BUS threshold monitoring at or below 13.8V triggers (MASTER CAUT) > MAIN BUS LV > -ESS BUS threshold monitoring at or below 13.0V triggers (MASTER WARN) ESS > BUS LV > I hope this is possible to setup with the G3X Touch, expert opinion is > welcomed. > > Shall the ESS-BUS relay fail, ESS-BUS alternate feed is provided by a > diode. -- https://CheerfulCurmudgeon.com/ *"Be kind, for everyone you meet is fighting a hard battle."* ________________________________ Message 3 _____________________________________ Time: 06:39:42 AM PST US Subject: Re: AeroElectric-List: Basic Elec. Diagram -critique pls From: Kelly McMullen Hard to judge without knowing anything about the electrical load besides you plan one electronic ignition. What do you expect normal cruise VFR load to be, normal IFR/IMC load, what you would shed if primary alternator failed. Is your normal mission pleasure VFR without "need" to keep a business schedule? Or you plan on business use that requires keeping a tighter schedule, flying as much IFR as needed, within airframe/equipment limits? Are you going with mechanical fuel injection or electronic fuel injection with required high pressure electric pump? What type of lighting with what current draw? I would defer deciding on brand and model of EFIS until you are ready to build the panel...new options come along every month. You likely will be modifying your electrical diagram up to that point as well. The items needed for install in the wing and fuselage are well defined. You will need a master solenoid at the battery in the rear compartment, nav and strobe lights and some form of landing light. All those can be wired generically until you are really ready to do the instrument panel/firewall wiring. On 1/13/2019 4:29 AM, supik wrote: > > (I have posted this on VAF as well) > > This is my preliminary diagram for my RV-10 > > Single battery, dual alternator setup. (60amp B&C + 30amp B&C) > Backup & Master switches ON during normal ops. > > Both alternators will be ON during normal ops. > ALT-1 (60amp) regulator preset at 14.4V > ALT-2 (30amp) regulator preset at 13.8V > > Both regulators are L3C-14 > LV lights from regulators NOT utilized. Respective BUS voltages monitored by G3X Touch. > -MAIN BUS threshold monitoring at or below 13.8V triggers (MASTER CAUT) MAIN BUS LV > -ESS BUS threshold monitoring at or below 13.0V triggers (MASTER WARN) ESS BUS LV > I hope this is possible to setup with the G3X Touch, expert opinion is welcomed. > > Shall the ESS-BUS relay fail, ESS-BUS alternate feed is provided by a diode. > > -------- > Igor > > RV10 in progress > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=486919#486919 > > > > > Attachments: > > http://forums.matronics.com//files/om_ela_basic_elec_diagram_v005_minor_txt_changes_144.jpg > > > > > > ________________________________ Message 4 _____________________________________ Time: 10:56:38 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Basic Elec. Diagram -critique pls At 05:29 AM 1/13/2019, you wrote: > >(I have posted this on VAF as well) > >This is my preliminary diagram for my RV-10 > >Single battery, dual alternator setup. (60amp B&C + 30amp B&C) >Backup & Master switches ON during normal ops. > >Both alternators will be ON during normal ops. E-bus alternate feed on or off? Why run both alternators? Driving the e-bus with an alternator makes the alternate feed path into an bus feeder with a potential current burden equal to the alternator output. The feeder needs to be beefed up to 10AWG, the S704 relay replaced with something more robust and you need to reconsider sizes and placment of feeder fuses. Let's back up and review the value for wiring other than what's shown in Z-12? Bob . . . ________________________________ Message 5 _____________________________________ Time: 10:56:57 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Basic Elec. Diagram -critique pls At 06:06 AM 1/13/2019, you wrote: >Igor, > >What are you going to connect to your essential bus? Do you need it >at all? I started with a wiring scheme like you have and eliminated >the ebus when I realized that, in case of a primary alternator >failure, I could simply turn off the pitot heat and landing lights. >That reduces the current draw below 30A. Exactly what happens in a TC aircraft with the sb alternator option (z-12). Bob . . . ________________________________ Message 6 _____________________________________ Time: 11:57:56 AM PST US Subject: AeroElectric-List: Re: Basic Elec. Diagram -critique pls From: "supik" art(at)zemon.name wrote: > Igor, > > > What are you going to connect to your essential bus? Do you need it at all? I started with a wiring scheme like you have and eliminated the ebus when I realized that, in case of a primary alternator failure, I could simply turn off the pitot heat and landing lights. That reduces the current draw below 30A. > > > -- Art Z. > > Art, for IFR in Europe we have to carry dual Nav/Coms and DME. With schedding Pitot heat and Land lights I would be still at 31amps with typical load only. The ESS BUS shall give me a quick shedding option to run only the most necessary equipment for completing the IFR flight safely and stay below 30amps. +Redundancy if the main battery contactor fails. -------- Igor RV10 in progress Read this topic online here: http://forums.matronics.com/viewtopic.php?p=486937#486937 ________________________________ Message 7 _____________________________________ Time: 12:04:07 PM PST US Subject: Re: AeroElectric-List: Re: Basic Elec. Diagram -critique pls From: Kelly McMullen Hmm, do you plan on old partial tube type navcoms like the KX170, or are you figuring power based on current draw for transmit, which is intermittent? Even KX-155 generation navcoms are under 3 amps in receive mode. 30 amps is a huge draw. Master relays failure rate is almost infinitesimal, if you define failure as not activating, or dropping out. Most common fault is developing high resistance, which is still functional for flight if you get the engine started. On 1/13/2019 12:57 PM, supik wrote: > > > art(at)zemon.name wrote: >> Igor, >> >> >> What are you going to connect to your essential bus? Do you need it at all? I started with a wiring scheme like you have and eliminated the ebus when I realized that, in case of a primary alternator failure, I could simply turn off the pitot heat and landing lights. That reduces the current draw below 30A. >> >> >> -- Art Z. >> >> > > > Art, for IFR in Europe we have to carry dual Nav/Coms and DME. With schedding Pitot heat and Land lights I would be still at 31amps with typical load only. The ESS BUS shall give me a quick shedding option to run only the most necessary equipment for completing the IFR flight safely and stay below 30amps. > > +Redundancy if the main battery contactor fails. > > -------- > Igor > > RV10 in progress > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=486937#486937 > > > > > > > > > ________________________________ Message 8 _____________________________________ Time: 12:16:25 PM PST US Subject: AeroElectric-List: Re: Basic Elec. Diagram -critique pls From: "supik" nuckolls.bob(at)aeroelect wrote: > > E-bus alternate feed on or off? Why > run both alternators? > > Driving the e-bus with an alternator > makes the alternate feed path into > an bus feeder with a potential > current burden equal to the alternator > output. The feeder needs to be beefed > up to 10AWG, the S704 relay replaced > with something more robust and you > need to reconsider sizes and placment > of feeder fuses. > > Let's back up and review the value > for wiring other than what's shown > in Z-12? > > > > Bob . . . My load analysis tells me the main alternator (ALT-1) would be above 80% at standard IFR ops with pitot heat ON. This is a little bit misleading as our rules require to calculate with the equipment's max draw and 1radio in TX mode -stupid but this is the local regulation. To comply with the regulation I have the standby alt (ALT-2) always ON. In case the draw will max out ALT-1, ALT-2 is supposed to take over. E BUS is fed from both the diode & the relay (which is always on during normal ops). You are right, I was too fast without crosschecking the wire sizes & relay's max amp. The battery will be a 24ah Concorde. What would be the correct fuse placement & size for the EBUS relay/contactor feed? Bob, thank you very much for sharing your diagrams & knowledge! -------- Igor RV10 in progress Read this topic online here: http://forums.matronics.com/viewtopic.php?p=486940#486940 ________________________________ Message 9 _____________________________________ Time: 12:30:48 PM PST US Subject: AeroElectric-List: Re: Basic Elec. Diagram -critique pls From: "supik" Kellym wrote: > Hmm, do you plan on old partial tube type navcoms like the KX170, or are > you figuring power based on current draw for transmit, which is > intermittent? Even KX-155 generation navcoms are under 3 amps in receive > mode. 30 amps is a huge draw. Master relays failure rate is almost > infinitesimal, if you define failure as not activating, or dropping out. > Most common fault is developing high resistance, which is still > functional for flight if you get the engine started. > > On 1/13/2019 12:57 PM, supik wrote: > > > > > > > > > art(at)zemon.name wrote: > > > Igor, > > > > > > > > > What are you going to connect to your essential bus? Do you need it at all? I started with a wiring scheme like you have and eliminated the ebus when I realized that, in case of a primary alternator failure, I could simply turn off the pitot heat and landing lights. That reduces the current draw below 30A. > > > > > > > > > -- Art Z. > > > > > > > > > > > > Art, for IFR in Europe we have to carry dual Nav/Coms and DME. With schedding Pitot heat and Land lights I would be still at 31amps with typical load only. The ESS BUS shall give me a quick shedding option to run only the most necessary equipment for completing the IFR flight safely and stay below 30amps. > > > > +Redundancy if the main battery contactor fails. > > > > -------- > > Igor > > > > RV10 in progress > > > > > > > > > > Read this topic online here: > > > > http://forums.matronics.com/viewtopic.php?p=486937#486937 > > > > > > > > > > > > > > > > > > > > > In real life, both radios in RX mode with ALL equipment ON I expect to be at 44Amps total with a typical load and 19.9Amps on the E BUS. Intermittent load not calculated. As mentioned before, the local load analysis has to calculate with max draw and 1 radio in TX mode. -------- Igor RV10 in progress Read this topic online here: http://forums.matronics.com/viewtopic.php?p=486941#486941 ________________________________ Message 10 ____________________________________ Time: 01:21:05 PM PST US Subject: AeroElectric-List: Re: Basic Elec. Diagram -critique pls From: "supik" Relay update, v.007 -------- Igor RV10 in progress Read this topic online here: http://forums.matronics.com/viewtopic.php?p=486942#486942 Attachments: http://forums.matronics.com//files/om_ela_basic_elec_diagram_v007_relay_change_150.jpg ________________________________ Message 11 ____________________________________ Time: 02:17:11 PM PST US Subject: AeroElectric-List: Re: Basic Elec. Diagram -critique pls From: "supik" v.008 (E BUS updated wire size & protection) peak max draw incl. intermittent draw is 33,7 Amps on the EBUS) -------- Igor RV10 in progress Read this topic online here: http://forums.matronics.com/viewtopic.php?p=486944#486944 Attachments: http://forums.matronics.com//files/om_ela_basic_elec_diagram_v008_e_bus_circuit_protection_125.jpg ________________________________ Message 12 ____________________________________ Time: 03:23:45 PM PST US From: Art Zemon Subject: Re: AeroElectric-List: Re: Basic Elec. Diagram -critique pls Igor, Did you do your load analysis at maximum current draw or at typical current draw? For instance, my VAL COM 2000 radio is 0.50 amps typical but 3.00 amps maximum (when transmitting). In the same vein, my pair of autopilot servos draw 1.80 amps typical and 3.42 maximum. For my BD-4C, my typical draw without pitot heat is 18.57 amps and max is 29.28 amps. The Dynon heated pitot tube is 10.00 amps with the heat on. Add 2.00 amps for USB devices and another 1.00 amp for something plugged into a 12V convenience outlet and my typical load is still 31.57 amps, which is darned close to what the B&C backup alternator can deliver at cruise RPM. I don't know what all equipment you have in your RV-10 but you might be overestimating your power requirements and nudging yourself toward an overly complex electrical system. -- Art Z. -- https://CheerfulCurmudgeon.com/ *"Be kind, for everyone you meet is fighting a hard battle."* ________________________________ Message 13 ____________________________________ Time: 04:19:24 PM PST US Subject: AeroElectric-List: Re: Basic Elec. Diagram -critique pls From: "supik" art(at)zemon.name wrote: > Igor, > > > Did you do your load analysis at maximum current draw or at typical current draw? For instance, my VAL COM 2000 radio is 0.50 amps typical but 3.00 amps maximum (when transmitting). In the same vein, my pair of autopilot servos draw 1.80 amps typical and 3.42 maximum. For my BD-4C, my typical draw without pitot heat is 18.57 amps and max is 29.28 amps. > > > The Dynon heated pitot tube is 10.00 amps with the heat on. Add 2.00 amps for USB devices and another 1.00 amp for something plugged into a 12V convenience outlet and my typical load is still 31.57 amps, which is darned close to what the B&C backup alternator can deliver at cruise RPM. > > > I don't know what all equipment you have in your RV-10 but you might be overestimating your power requirements and nudging yourself toward an overly complex electrical system. > > > -- Art Z. > > > > -- > https://CheerfulCurmudgeon.com/ (https://CheerfulCurmudgeon.com/)"Be kind, for everyone you meet is fighting a hard battle." Art, My TYPICAL TOTAL Draw incl. lights, pitot heat & usb.. is recalculated: 46Amps (both Coms RX) -intermittent loads excluded. If I turn off pitot heat and land lights, I'll end up with 32.3 TOTAL TYPICAL Draw. With further avionics load shedding I can get below 30Amps of course. Would you suggest that the E BUS architecture makes little sense? -------- Igor RV10 in progress Read this topic online here: http://forums.matronics.com/viewtopic.php?p=486947#486947 ________________________________ Message 14 ____________________________________ Time: 04:33:43 PM PST US Subject: AeroElectric-List: Re: Basic Elec. Diagram -critique pls From: "supik" My Load Analysis attached: -------- Igor RV10 in progress Read this topic online here: http://forums.matronics.com/viewtopic.php?p=486948#486948 Attachments: http://forums.matronics.com//files/loadanalysis_om_ela_v23_lr3c_14_regulators_added_179.pdf ________________________________ Message 15 ____________________________________ Time: 06:53:44 PM PST US Subject: Re: AeroElectric-List: Re: Basic Elec. Diagram -critique pls From: Kelly McMullen I don't begin to understand some of the math you are doing on your spreadsheet analysis, but I see several areas that I would consider differently. Landing lights are not continuous for anything but perhaps the last mile of landing. Cockpit LEDs are unlikely to be used during flight more than intermittently. Your LED strobe values seem about double what mine are. Using your values I come up with about 24 amps for IFR flight. USB charger is not needed during any alternator failure scenario..your portable/backup GPS has an internal battery for that situation. I would get rid of the rudder trim servo. It is not needed. Once you get a fixed trim wedge sized for cruise flight, the force needed for climb or descent is about the same or less than a Cessna 172. You may consider a yaw damper, which will also deal with the slight rudder forces needed in non-cruise condition. Putting even a relatively light weight of a servo in the rudder will change its harmonic balance, which is undesirable. There is a reason that Vans recommends a plastic or wood wedge for cruise trim. I also don't use roll trim..just keeping your fuel tanks switched at least once an hour is sufficient. Your roll servo will handle any minor imbalances. Unless you regularly fly in visible moisture, you won't use pitot heat continuously. In summary, I think your electrical needs are about 60% what your totals show. Your battery will handle the intermittent loads. On 1/13/2019 5:32 PM, supik wrote: > > My Load Analysis attached: > > -------- > Igor > > RV10 in progress > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=486948#486948 > > > > > Attachments: > > http://forums.matronics.com//files/loadanalysis_om_ela_v23_lr3c_14_regulators_added_179.pdf > > > > > > ________________________________ Message 16 ____________________________________ Time: 07:13:53 PM PST US From: Art Zemon Subject: Re: AeroElectric-List: Re: Basic Elec. Diagram -critique pls Igor, You have certainly done your homework on the load analysis. A few things stand out when I look at the IFR night cruise column, which is 56 amps. You have the 12 amp pitot heat as a continuous load. I always used pitot heat when the temp was 10C or colder and there was visible moisture. My personal limitations call for pitot heat as a last resort. I am not interested in continued flight into possible icing conditions an my airplane. If I have the pitot heat on, it is temporary, either because I am climbing to known clear air above the clouds or because I am landing. I don't have my GTN650 (I will install that next fall) but I am very surprised to see a combined load of 1.16 + 2.80 + 4.02 = 8 amps continuous. That's a boatload of power! You've got two radio receivers and a small display screen for continuous load. That 8 amp figure has me scratching my head. My nav and com radios, combined, have a continuous load of just 1 amp. The audio panel at 2.39 amps is another head scratcher. My PS Engineering audio panel has a continuous load of 0.35 amps. I also wonder about the continuous load for your display units. You list them at 2 amps each. I have MGL displays which are 10.4 inches diagonally and they only draw 1.20 continuous (each) and 2.25 max. I don't know the Garmin product line at all so you may well be spot on with your analysis. If you are, and you are willing to fly in conditions when you need your pitot heat for a long time, then I applaud your planning. You can see the load analysis for my plane on this page: https://drive.google.com/file/d/0BzOP2gb9_3RQSU5qbVN1ckJNOUk/view?usp=sharing -- Art Z. -- https://CheerfulCurmudgeon.com/ *"Be kind, for everyone you meet is fighting a hard battle."* ________________________________ Message 17 ____________________________________ Time: 07:31:42 PM PST US Subject: Re: AeroElectric-List: Re: Basic Elec. Diagram -critique pls From: Charlie England This has come up before, but it's worthwhile to actually measure current draw for each device. The mfgrs often are quite conservative (meaning that they overstate) power demands for their devices. I've measured a few of my devices, and some draw less than half what their data sheets say. Charlie On 1/13/2019 9:12 PM, Art Zemon wrote: > Igor, > > You have certainly done your homework on the load analysis. A few > things stand out when I look at the IFR night cruise column, which is > 56 amps. > > You have the 12 amp pitot heat as a continuous load. I always used > pitot heat when the temp was 10C or colder and there was visible > moisture. My personal limitations call for pitot heat as a last > resort. I am not interested in continued flight into possible icing > conditions an my airplane. If I have the pitot heat on, it is > temporary, either because I am climbing to known clear air above the > clouds or because I am landing. > > I don't have my GTN650 (I will install that next fall) but I am very > surprised to see a combined load of 1.16+ 2.80+ 4.02 = 8 amps > continuous. That's a boatload of power! You've got two radio receivers > and a small display screen for continuous load. That 8 amp figure has > me scratching my head. My nav and com radios, combined, have a > continuous load of just 1 amp. > > The audio panel at 2.39 amps is another head scratcher. My PS > Engineering audio panel has a continuous load of 0.35 amps. > > I also wonder about the continuous load for your display units. You > list them at 2 amps each. I have MGL displays which are 10.4 inches > diagonally and they only draw 1.20 continuous (each) and 2.25 max. > > I don't know the Garmin product line at all so you may well be spot on > with your analysis. If you are, and you are willing to fly in > conditions when you need your pitot heat for a long time, then I > applaud your planning. > > You can see the load analysis for my plane on this page: > https://drive.google.com/file/d/0BzOP2gb9_3RQSU5qbVN1ckJNOUk/view?usp=sharing > > -- Art Z. > > -- > https://CheerfulCurmudgeon.com/ > > /"Be kind, for everyone you meet is fighting a hard battle."/ --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ________________________________ Message 18 ____________________________________ Time: 07:34:22 PM PST US Subject: Re: AeroElectric-List: Re: Basic Elec. Diagram -critique pls From: Kelly McMullen The GTN 650 in receive mode is 3.5 amps. The screen and GPS receivers are 3 amps and the com is .5. I agree the audio panel power is negligible. I also agree with pitot heat rarely being needed continously, unless someone is a lot bolder than I am. I don't know how the RV-10 wing and tail perform in icing, and have no intention of finding out. When I am doing training or maintenance that needs my panel on ground power, a 10 amp charger struggles a bit to keep up, but 15 amps more than covers the need. On 1/13/2019 8:12 PM, Art Zemon wrote: > Igor, > > You have certainly done your homework on the load analysis. A few things > stand out when I look at the IFR night cruise column, which is 56 amps. > I don't have my GTN650 (I will install that next fall) but I am very > surprised to see a combined load of 1.16+ 2.80+ 4.02 = 8 amps > continuous. That's a boatload of power! > > The audio panel at 2.39 amps is another head scratcher. My PS > Engineering audio panel has a continuous load of 0.35 amps. > > I also wonder about the continuous load for your display units. You list > them at 2 amps each. I have MGL displays which are 10.4 inches > diagonally and they only draw 1.20 continuous (each) and 2.25 max. > > I don't know the Garmin product line at all so you may well be spot on > with your analysis. If you are, and you are willing to fly in conditions > when you need your pitot heat for a long time, then I applaud your planning. > > You can see the load analysis for my plane on this page: > https://drive.google.com/file/d/0BzOP2gb9_3RQSU5qbVN1ckJNOUk/view?usp=sharing > > -- Art Z. > > -- > https://CheerfulCurmudgeon.com/ > > /"Be kind, for everyone you meet is fighting a hard battle."/ ________________________________ Message 19 ____________________________________ Time: 08:02:37 PM PST US Subject: AeroElectric-List: Internally Regulated Over Voltage Protection From: "BMC_Dave" I see that schematics for providing over voltage regulation on internally regulated alternators have been scrubbed: http://www.aeroelectric.com/DIY/DIY_Crowbar_OVP_F.pdf Looks like the last rev was in 2005. Has there been any changes in thinking in the last 14 years as to the use of internally regulated alternators? Is there possibly an example of this safety features use on an IR alternator I can see so I can at least have the information? Any help is greatly appreciated, thanks. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=486953#486953 ________________________________ Message 20 ____________________________________ Time: 09:01:49 PM PST US Subject: AeroElectric-List: Re: Internally Regulated Over Voltage Protection From: "BMC_Dave" After finding Z-24 I wonder if leaving the ebus alt feed closed normally would help with load dumps for in flight switching off of the alternator? The easiest solution is to turn off the engine first when shutting down. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=486954#486954 ________________________________ Message 21 ____________________________________ Time: 09:39:41 PM PST US Subject: Re: AeroElectric-List: Re: Basic Elec. Diagram -critique pls From: Rick Beebe On 1/13/2019 10:12 PM, Art Zemon wrote: > I don't have my GTN650 (I will install that next fall) but I am very > surprised to see a combined load of 1.16+ 2.80+ 4.02 = 8 amps > continuous. That's a boatload of power! You've got two radio receivers > and a small display screen for continuous load. That 8 amp figure has > me scratching my head. My nav and com radios, combined, have a > continuous load of just 1 amp. That's the maximum draw at 14 volts. 2.8 on the main connector, 4.0 on the com while transmitting, and 1.16 on the nav. "Typical" current draw is 1.6, .45 and .60. --Rick ________________________________ Message 22 ____________________________________ Time: 10:19:32 PM PST US From: Sebastien Subject: Re: AeroElectric-List: Re: Basic Elec. Diagram -critique pls Art and Igor, as someone with about 700 hours of actual time in cloud I feel competent to comment on pitot heat use. There is a reason the POH for any TC aircraft meant to be operated in IFR conditions will have pitot heat on before takeoff. There is a reason many aircraft will give you a warning if they get airborne with the pitot heat off. The problem with turning on pitot heat once you need it is that your first indication of that need may be the loss of all speed indications. While this should not necessarily be fatal for a current and competent pilot, it has proved fatal many times, especially on departure. If you are flying IFR or at night, turn the pitot heat on before takeoff and leave it on until after landing. I regularly fly IFR in AB and TC aircraft with 1 alternator and 1 battery so as others have stated, I find the design goal of a second alternator that can carry all loads indefinitely to be not useful but no matter what the goal, including continuous use of pitot heat for an IFR aircraft is a must in my books and any aircraft manufacturer's books I have ever seen. Regards, Sebastien On Jan 13, 2019 7:18 PM, "Art Zemon" wrote: Igor, You have certainly done your homework on the load analysis. A few things stand out when I look at the IFR night cruise column, which is 56 amps. You have the 12 amp pitot heat as a continuous load. I always used pitot heat when the temp was 10C or colder and there was visible moisture. My personal limitations call for pitot heat as a last resort. I am not interested in continued flight into possible icing conditions an my airplane. If I have the pitot heat on, it is temporary, either because I am climbing to known clear air above the clouds or because I am landing. I don't have my GTN650 (I will install that next fall) but I am very surprised to see a combined load of 1.16 + 2.80 + 4.02 = 8 amps continuous. That's a boatload of power! You've got two radio receivers and a small display screen for continuous load. That 8 amp figure has me scratching my head. My nav and com radios, combined, have a continuous load of just 1 amp. The audio panel at 2.39 amps is another head scratcher. My PS Engineering audio panel has a continuous load of 0.35 amps. I also wonder about the continuous load for your display units. You list them at 2 amps each. I have MGL displays which are 10.4 inches diagonally and they only draw 1.20 continuous (each) and 2.25 max. I don't know the Garmin product line at all so you may well be spot on with your analysis. If you are, and you are willing to fly in conditions when you need your pitot heat for a long time, then I applaud your planning. You can see the load analysis for my plane on this page: https://drive.google.com/file/d/0BzOP2gb9_3RQSU5qbVN1ckJNOUk/view?usp=sharing -- Art Z. -- https://CheerfulCurmudgeon.com/ *"Be kind, for everyone you meet is fighting a hard battle."* ------------------------------------------------------------------------------------- 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.