---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Wed 01/04/17: 15 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:31 AM - Re: EMI From Seat Heaters and Other Questions (Alec Myers) 2. 04:42 AM - Re: EMI From Seat Heaters and Other Questions (Alec Myers) 3. 05:07 AM - Re: EMI From Seat Heaters and Other Questions (Alec Myers) 4. 08:43 AM - Re: Z-13/8 and SD-8 (user9253) 5. 08:56 AM - Re: SD-20/SD-60 Question (Bill Watson) 6. 10:16 AM - Re: SD-20/SD-60 Question (Robert L. Nuckolls, III) 7. 11:00 AM - Conduit and adding wires (Bill Schertz) 8. 11:22 AM - Rotax 912iS questions (GTH) 9. 11:49 AM - Re: Rotax 912iS questions (Charlie England) 10. 02:22 PM - EMI From Seat Heaters and Other Questions (Owen Baker) 11. 03:29 PM - Re: SD-20/SD-60 Question (William Hunter) 12. 03:32 PM - Re: EMI From Seat Heaters and Other Questions (William Hunter) 13. 04:52 PM - Re: EMI From Seat Heaters and Other Questions (Charlie England) 14. 06:29 PM - Re: EMI From Seat Heaters and Other Questions (Robert L. Nuckolls, III) 15. 09:18 PM - Re: EMI From Seat Heaters and Other Questions (Buckaroo Banzai) ________________________________ Message 1 _____________________________________ Time: 04:31:54 AM PST US From: Alec Myers Subject: Re: AeroElectric-List: EMI From Seat Heaters and Other Questions Someone has their units mixed up here. BTU is a measure of energy. Heaters a re measured in BTU/hour. (Like the difference between joules and watts). 480 W is 1638BTU/h, and 8000BTU/h is 2344W so the two figures given don't seem t o agree. The former seems more reasonable than the latter for this unit. On Jan 3, 2017, at 23:50, Eric Page wrote: > On Jan 3, 2017, at 6:20 PM, William Hunter wr ote: > QUESTION 4: How much heat would a small 12 VDC electric element heater sy stem realistically put out? This is the one we have been discussing it is de signed for a RV unit: http://www.my12voltstore.com/12_Volt_Ducted_Heater_p /sd12-4000.htm > At the risk of being pedantic, I'm not sure how one would answer this other t han to quote the product's specifications and explain the units. The description says this heater rated for 8,016 British Thermal Units (BTUs ). A BTU is the amount of energy it takes to heat one pound of water (about 16 fl oz, or two cups) by one degree Fahrenheit. So, the heat energy this thing puts out could heat a 4-ton tank of water (ap prox 960 US gal) by one deg F in one hour. Or, to use numbers that are a bi t more meaningful, heat about 96 gal of water by 10 deg F in one hour. Stil l not a very helpful comparison. The specs say it draws 480W (40A at 12V). It looks like the blower motor ac counts for 15W (1.25A) of that total, which leaves 465W (38.75A) for the hea ting elements. That's a decent amount of heat, but compare that figure agai nst a typical small domestic space heater that we're all familiar with: they 're commonly rated at 1,500W. The first three search results for "hair drye r" on Amazon are rated at 1,875W! Recommendations vary between 20 and 60 BTU/sq ft for heating a home, dependi ng on your climate region. If you assume a middle value of 40 BTU/sq ft, th en 8,000 BTU would be about right for a 200 sq ft room (in a home insulated t o code). Whether that kind of analysis translates to airplanes, or if 8,000 BTU is ad equate for a light plane cockpit flying through freezing air are interesting questions. How warm is warm enough? Eric ________________________________ Message 2 _____________________________________ Time: 04:42:44 AM PST US From: Alec Myers Subject: Re: AeroElectric-List: EMI From Seat Heaters and Other Questions One might also point out that trying to heat a space from a 12v supply is li ke filling a swimming pool from a garden hose. Don't expect too much - there 's a reason that where the aviation community can't use exhaust muff heating systems (cabin twins, for instance) they don't try electric, they use Janit rol heaters. On Jan 3, 2017, at 23:50, Eric Page wrote: > On Jan 3, 2017, at 6:20 PM, William Hunter wr ote: > QUESTION 4: How much heat would a small 12 VDC electric element heater sy stem realistically put out? This is the one we have been discussing it is de signed for a RV unit: http://www.my12voltstore.com/12_Volt_Ducted_Heater_p /sd12-4000.htm > At the risk of being pedantic, I'm not sure how one would answer this other t han to quote the product's specifications and explain the units. The description says this heater rated for 8,016 British Thermal Units (BTUs ). A BTU is the amount of energy it takes to heat one pound of water (about 16 fl oz, or two cups) by one degree Fahrenheit. So, the heat energy this thing puts out could heat a 4-ton tank of water (ap prox 960 US gal) by one deg F in one hour. Or, to use numbers that are a bi t more meaningful, heat about 96 gal of water by 10 deg F in one hour. Stil l not a very helpful comparison. The specs say it draws 480W (40A at 12V). It looks like the blower motor ac counts for 15W (1.25A) of that total, which leaves 465W (38.75A) for the hea ting elements. That's a decent amount of heat, but compare that figure agai nst a typical small domestic space heater that we're all familiar with: they 're commonly rated at 1,500W. The first three search results for "hair drye r" on Amazon are rated at 1,875W! Recommendations vary between 20 and 60 BTU/sq ft for heating a home, dependi ng on your climate region. If you assume a middle value of 40 BTU/sq ft, th en 8,000 BTU would be about right for a 200 sq ft room (in a home insulated t o code). Whether that kind of analysis translates to airplanes, or if 8,000 BTU is ad equate for a light plane cockpit flying through freezing air are interesting questions. How warm is warm enough? Eric ________________________________ Message 3 _____________________________________ Time: 05:07:24 AM PST US From: Alec Myers Subject: Re: AeroElectric-List: EMI From Seat Heaters and Other Questions Last post for now, I promise: the Janitrol approved for installation in a (4 seat) Cessna 170 is 25000BTU/h which is 7.3kW. Compare 500w... On Jan 4, 2017, at 07:41, Alec Myers wrote: One might also point out that trying to heat a space from a 12v supply is li ke filling a swimming pool from a garden hose. Don't expect too much - there 's a reason that where the aviation community can't use exhaust muff heating systems (cabin twins, for instance) they don't try electric, they use Janit rol heaters. On Jan 3, 2017, at 23:50, Eric Page wrote: > On Jan 3, 2017, at 6:20 PM, William Hunter wr ote: > QUESTION 4: How much heat would a small 12 VDC electric element heater sy stem realistically put out? This is the one we have been discussing it is de signed for a RV unit: http://www.my12voltstore.com/12_Volt_Ducted_Heater_p /sd12-4000.htm > At the risk of being pedantic, I'm not sure how one would answer this other t han to quote the product's specifications and explain the units. The description says this heater rated for 8,016 British Thermal Units (BTUs ). A BTU is the amount of energy it takes to heat one pound of water (about 16 fl oz, or two cups) by one degree Fahrenheit. So, the heat energy this thing puts out could heat a 4-ton tank of water (ap prox 960 US gal) by one deg F in one hour. Or, to use numbers that are a bi t more meaningful, heat about 96 gal of water by 10 deg F in one hour. Stil l not a very helpful comparison. The specs say it draws 480W (40A at 12V). It looks like the blower motor ac counts for 15W (1.25A) of that total, which leaves 465W (38.75A) for the hea ting elements. That's a decent amount of heat, but compare that figure agai nst a typical small domestic space heater that we're all familiar with: they 're commonly rated at 1,500W. The first three search results for "hair drye r" on Amazon are rated at 1,875W! Recommendations vary between 20 and 60 BTU/sq ft for heating a home, dependi ng on your climate region. If you assume a middle value of 40 BTU/sq ft, th en 8,000 BTU would be about right for a 200 sq ft room (in a home insulated t o code). Whether that kind of analysis translates to airplanes, or if 8,000 BTU is ad equate for a light plane cockpit flying through freezing air are interesting questions. How warm is warm enough? Eric ________________________________ Message 4 _____________________________________ Time: 08:43:24 AM PST US Subject: AeroElectric-List: Re: Z-13/8 and SD-8 From: "user9253" Bob, thanks for that explanation. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=464694#464694 ________________________________ Message 5 _____________________________________ Time: 08:56:35 AM PST US Subject: Re: AeroElectric-List: SD-20/SD-60 Question From: Bill Watson On 1/3/2017 9:55 PM, William Hunter wrote: > > I am running a SD-60 and a LR3C-14 Voltage Regulator on one bus with > its own battery and a SD-20 with its own LR3C-14 Voltage Regulator on > the second bus with its own battery. The engine is a Lycoming IO-540. > I have been operating an RV10 with a Z-14, LR3Cs, an SD40 and SD20, all on an IO-540. A Z-14 is what you are describing. > > QUESTION 1: I intend to operate my two electrical systems isolated > with a bus tie that will be used for engine start only and then untied > afterwards. What happens if I forget to untie the two busses after > engine start and both the SD-60 and the SD-20 are providing current to > the combined system? Do they share the load equally on the combined > system? What happens should the system load reach 50 AMPS? Does the > SD-20 simply max out at 20 AMPS and then the SD-60 picks up the rest > of the 30 AMPS? > Operationally, the idea is to use the systems tied for the start, then untie them for flight. I've run them both ways, 50:50, over 800 hours. No problems either way but I can't tell you exactly what was charging what, when, due a voltage measurement problem (see way below). A big reason you run them split is so you can detect any problems. I recently 'lost' the SD-40 in IMC - low voltage light came on and bus voltage dropped to battery levels on the one bus. Nothing popped or anything so I simply cross-tied the buses and turned off the Alt/Batt switch on the SD-40 side. The SD-20 kept the voltage at an acceptable, constant level until the flight was completed. (the problem on the SD-40 bus turned out to a degraded connection somewhere in the LR3-switch-bus circuit that detects field voltage. Executing B&C LR3 troubleshooting procedure identified the problem. All connections were physically reset and problem resolved) > > QUESTION 2: If I do remember to untie the bussesWhat happens to the > single system when there is a temporary current spike on that isolated > system? Example: Should the alternator be running at 90 percent of > its capacity and then the electric landing gear hydraulic pump cycles > and draws another 25-30 AMPS. Does the voltage regulator simply limit > the alternator output to its max output of 60/20 AMPS and then the > system draws down the battery during the short time the gear pump is > active or does the voltage regulator deactivate the SD-60 requiring a > reset? > Just like a single bus/alt/batt, it draws on the battery but you won't even notice. > > QUESTION 3: How much output does the SD-60 and the SD-20 really put > out both at idle and at cruise RPM? I heard that the belt driven > alternator will put out full production at low RPM however the SD-20 > will only put out lower production at low RPM and only reach its full > rated production at max RPM? > Yes, the SD-20 will put out considerably less than 20amps at idle. Doesn't really matter in my experience Voltage Measurement: I created a problem with how I measured bus voltages. I have a GRT panel with (3) EFISs and (1) EIS. I took one voltage measurement from the EIS and the other from the EFIS, and then displayed the 2 voltages on the EFIS. This was easy since the EFISs were on 1 bus and the EIS on the other. In both cases I was getting the voltage level of the feeds for each system. However the EFISs represent a significant load and the voltage there was about .6 volts less than bus voltage. On the other hand, the EIS is a very low, constant load device and the voltage there more or less was equal to bus voltage. Many problems resulted from this. The solution is to get your 2 bus measurements from places that match bus voltages. Load Balancing: Distinguish between constant loads and temporary loads. My understanding is that you generally balance for constant loads (Powered on panel devices, strobes, running lights) and rely on your excess capacity and battery for the others (gear, landing lights, radio transmit, engine start). I got a bit fancy and started with too many constant loads on the SD-20. Though the SD-20 will run everything on both buses in daytime cruise and keep the battery fully charged. Charging voltage levels: If you are using AGM batteries (PC680s here) be careful about low bus voltages. 14.2 is a good minimum and you should see at least 14 on both buses at shutdown. Anything less means that your battery is being stored at less than full charge and that will shorten its life. Any shutdown voltage level of 13.x is going to cost you extra battery money in my experience. Bill "wishing for FIKI" Watson --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ________________________________ Message 6 _____________________________________ Time: 10:16:27 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: SD-20/SD-60 Question I am running a SD-60 and a LR3C-14 Voltage Regulator on one bus with its own battery and a SD-20 with its own LR3C-14 Voltage Regulator on the second bus with its own battery. The engine is a Lycoming IO-540. Okay, Figure Z-14 . . . QUESTION 1: I intend to operate my two electrical systems isolated with a bus tie that will be used for engine start only and then untied afterwards. What happens if I forget to untie the two busses after engine start and both the SD-60 and the SD-20 are providing current to the combined system? Do they share the load equally on the combined system? What happens should the system load reach 50 AMPS? Does the SD-20 simply max out at 20 AMPS and then the SD-60 picks up the rest of the 30 AMPS? Not necessarily. Both regulators should be set for optimal BATTERY maintenance (14.2 to 14.6 volts). It's practically impossible to set them to the same voltage. Hence, while paralleled, the alternator with the slightly higher setting will 'hog' the load until such time as it maxes out, bus voltage falls until the alternator with the lower set-point picks up the difference. QUESTION 2: If I do remember to untie the busses . . . How would this happen? If wired per the published drawing, the crossfeed contactor is automatically closed when a SPRING LOADED switch is moved to START position. This gets you two batteries for cranking while illuminating a CROSSFEED WARN light. When the engine starts, the switch is released, the contactor opens, the light goes out. Nothing to 'forget'. Emacs! What happens to the single system when there is a temporary current spike on that isolated system? Example: Should the alternator be running at 90 percent of its capacity and then the electric landing gear hydraulic pump cycles and draws another 25-30 AMPS. Does the voltage regulator simply limit the alternator output to its max output of 60/20 AMPS and then the system draws down the battery during the short time the gear pump is active or does the voltage regulator deactivate the SD-60 requiring a reset? Not sure what the concern is here. First, how do you expect to normally load either alternator so heavily? Both sides should be designed to achieve 25% or so of headroom on the alternator for battery charging. But even if the inrush current from a pump motor exceeds an alternator's rated capacity, the bus voltage sags, the battery picks up the difference, and all returns to normal after the event . . . which is generally over in tens of milliseconds. No big deal. QUESTION 3: How much output does the SD-60 and the SD-20 really put out both at idle and at cruise RPM? I heard that the belt driven alternator will put out full production at low RPM however the SD-20 will only put out lower production at low RPM and only reach it's full rated production at max RPM? Generally true. Don't go by what you HEAR . . . go get the specs from the folks who design, manufacture, sell and support the systems. Generally speaking, B&C belt driven alternators DO run fast . . . unlike alternators deliberately slowed by installation of larger pulleys (to save bearings), the B&C alternators (and most others) produce a substantial fraction of rated output at taxi speeds. The SD-20 is mechanically crippled by installation on a drive pad with a max rpm on the order of 4K . . . LESS than minimum speed for full output from the 40A core from which the SD-20 is manufactured. Have offered that, it behooves every builder to KNOW what the in flight running loads are on ANY alternators. To KNOW what headroom is available to recharge the companion battery. To KNOW what energy levels are stored in any combination of batteries. Figure Z-14 offers a tall fire-wall against failures but it does not negate the value of discovering and understanding EVERYTHING there is to know about how all the pieces fit together along with the effect any single failure might have on in-flight systems operations. Bob . . . --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ________________________________ Message 7 _____________________________________ Time: 11:00:48 AM PST US From: "Bill Schertz" Subject: AeroElectric-List: Conduit and adding wires One other technique for adding a wire to an existing conduit if you don't have the embedded string is to take a length of 1/4" polyethylene tubing, run it down the existing conduit (may have to occasionally turn it) it is stiff enough to allow you to install it, then run the wire into the tube, fasten the far end and pull the tube back out. The slippery nature of the tubing makes pushing the wire through easy,. Bill Schertz ________________________________ Message 8 _____________________________________ Time: 11:22:01 AM PST US From: GTH Subject: AeroElectric-List: Rotax 912iS questions Hi all, Presently considering the wiring of a Rotax 912iS in a friend's composite project. The engine features a digital fuel injection with high pressure fuel pumps, digital control "lanes", backup power circuit, dual alternator with control box etc. The Rotax Installation manual calls for a certain number of panel switches : Pump A and B switches (permanent) : 10 A each Lane A & B switches (permanent) : 7.5 A each Engine Control Unit start power switch (momentary) : 20 A Backup battery switch (permanent) : 20 A QUESTION : is it advisable to bring such heavy current carrying wires to the panel, or would it be preferable to use relays to control the system ? Any input appreciated, Thanks in advance, -- Best regards, Gilles http://contrails.free.fr http://lapierre.skunkworks.free.fr ________________________________ Message 9 _____________________________________ Time: 11:49:28 AM PST US Subject: Re: AeroElectric-List: Rotax 912iS questions From: Charlie England On 1/4/2017 1:21 PM, GTH wrote: > > Hi all, > > Presently considering the wiring of a Rotax 912iS in a friend's > composite project. > > The engine features a digital fuel injection with high pressure fuel > pumps, digital control "lanes", backup power circuit, dual alternator > with control box etc. > > The Rotax Installation manual calls for a certain number of panel > switches : > > Pump A and B switches (permanent) : 10 A each > > Lane A & B switches (permanent) : 7.5 A each > > Engine Control Unit start power switch (momentary) : 20 A > > Backup battery switch (permanent) : 20 A > > QUESTION : is it advisable to bring such heavy current carrying wires > to the panel, or would it be preferable to use relays to control the > system ? > > Any input appreciated, > > Thanks in advance, > > > -- > Best regards, > Gilles > http://contrails.free.fr > http://lapierre.skunkworks.free.fr For me, the decisions were based both on overall weight, and complexity/reliability (yes, I know they aren't necessarily the same thing, but can be related). How much weight (length has a big influence) will using the heavier gauge wire add, vs the added weight of the relay? How much reliability will you sacrifice by adding a relay and all the extra terminations required? Even 20 A is not that big a deal for the proper switch. Going bigger than that, a relay starts to look more attractive, especially since the automotive world now makes fairly light weight, high current relays available for very reasonable prices. Charlie ________________________________ Message 10 ____________________________________ Time: 02:22:09 PM PST US From: "Owen Baker " Subject: AeroElectric-List: EMI From Seat Heaters and Other Questions 1/4/2017 Hello Bill Hunter, I could not find enough space under the engine cowling to put a heat muff on the exhaust system of my KIS TR-1 airplane powered by a Continental Motors IO-240 B9B engine. I initially tried to use an recreational vehicle heater similar to your: http://www.my12voltstore.com/12_Volt_Ducted_Heater_p/sd12-4000.htm It generated about as much heat as waving a lighted cigarette around in the cockpit. Also it generated noise on the radio. Totally useless. My solution was electrically heated clothing like the motorcyclists and the snowmobile riders use. My brand was Gerbings bought several years ago which has worked great. That company=99s recent history is shaky so shop around before you buy. OC ============= Time: 06:23:06 PM PST US From: "William Hunter" Subject: AeroElectric-List: EMI From Seat Heaters and Other Questions Hi AeroElectric Cyber Friends!!! I figured I would bounce these questions off of the folks on this forum. Over at the Velocity Aircraft Forum we have some questions with respect to EMI from 12 VDC supplemental cabin heat systems such as heated seats, heated blankets (such as an electric blanket that you plug into the cigarette lighter), and/or a 12 volt electric heating element heater. QUESTION 1: Would the heat blanket/seat system affect the magnetometer on the aircraft? The 12 VDC electric heater has a motor and an element so that certainly might cause issues. If so how far away would you consider it the reasonable distance from the magnetometer to the heated element in the blanket/seat? QUESTION 2: If the heated seat would cause EMI, is it possible to mitigate the EMI by "polarizing" the seat inserts (placing one element in one direction and the other in the opposite direction? This is the heated seat kit I bought for my aircraft: https://www.amazon.com/Water-Carbon-Premium-Heated-Seats/dp/B00AKEVNP2/re f=s r_1_10?ie=UTF8&qid=1483494619&sr=8-10&keywords=car%2Bheated%2Bsea ts&th=1 QUESTION 3: Would an electric seat/blanket cause radio noise? If so what can one do to mitigate the noise? QUESTION 4: How much heat would a small 12 VDC electric element heater system realistically put out? This is the one we have been discussing it is designed for a RV unit: http://www.my12voltstore.com/12_Volt_Ducted_Heater_p/sd12-4000.htm Does anybody happen to have any experience with this particular unit and to see if it's worth the cost / weight penalty involved in hauling this thing around. I was thinking of installing this under the instrument panel and using it as a defroster by directing the "heated" air toward the windshield. We are in a "heated discussion" on how to add a heat source to the airplane. The only heat in the velocity airplane design is an oil cooler mounted in the nose and that air/oil heat exchanger is used for cabin heat.the problem being that outside air is blown through the oil cooler and into the cabin and naturally during cold months the OAT is significantly cold and therefore the heat increase is not very efficient plus the fact that our air cooled engines may not be producing that much oil temperature to begin with so we are dreaming of ways to supplement our interior heat. Any suggestions/feedback/experience would be greatly appreciated!!! THANKS!!! Bill Hunter ________________________________ Message 11 ____________________________________ Time: 03:29:54 PM PST US From: "William Hunter" Subject: RE: AeroElectric-List: SD-20/SD-60 Question Joe and Bob, I am VERY GRATEFUL for your help on this!!! >Okay, Figure Z-14 . . . Yes exactly.I stole that idea from the best source I could find. I did not go with the auto bus tie option however. >Both sides should be designed to achieve 25% or so of headroom on the alternator for battery charging. Can you all PLEASE check my homework on the current draw of the proposed equipment on each system? Naturally not all of these items will be running at the same time so it is hard to try to figure out what the actual steady state load will be. EXAMPLE: On hot days I will need the turbo intercooler electric fans but no pitot heat nor heated seats and vice versa. Communications radios on receive mode draw very little however when transmitting they draw 3 AMPS for only that time. I will be running two Dynon SV-1000s and each will be powered by its onside independent electrical system. Red System Loads (SD-20): The left system with the SD-20 is called "RED" (because there is a red light on the left wingtip). CB NAME AMP ITEM ON RED (PILOT SIDE) BUS BAR VOLT REG SENSE 2 LR3C-14 Voltage Regulator BUS VOLTAGE SENSE VOLT REG FIELD 5 VOLTAGE REGULATOR FIELD EFIS 5 Pilot side EFIS system SV-D1000 10" SKYVIEW DISPLAY 3.5amp SV-GPS-250 GPS MODULE 0.10amp SV-BAT-320 1.00 amp (only when at max charge) SV-ADAHRS-200 0.15amp USB WiFi ADAPTER 0.10amp SV-ARINC-429 0.10amp SV-KNOB-PANEL 0.07 amp SV-AP-PANEL 0.05 amp SV-EMS220 0.11amp SV COM 5 SV-COM-425 0.2amp continuous in RCV mode 3 amp only during XMT SV-AP SERVO 5 SV-AP SERVO Pitch servo 2 amps only when moving at MAX torque Roll servo 2 amps only when moving at MAX torque SV-AP POWER 3 SV-AP UNIT AP control box less than 3 amps TAXI LIGHT 5 TAXI LIGHT IN NOSE ENG FAN 2 ELECTRIC TURBO INTERCOOLER COOLING FANS ACCY FEED This CB powers the accessory power for the relays only. There are two engine cooling fans mounted below the turbocharger intercooler and there are two relays (one for each fan) attached to the battery box and each relay needs a 12V signal for accessory on and then it also needs a ground signal to close the relay contacts that power the fans. The ground signal is provided by switched ground. When the relay closes the fans get their power feed directly from the GREEN battery output through a 30 AMP inline fuse. The Intercooler fans provide supplemental ground and climb cooling to the intercooler and engine and therefore this system is not required for flight GREEN BUS SD-60 The right system with the SD-60 is called "GREEN" (you get the idea). CB NAME AMP ITEM ON MAIN BUS BAR VOLT REG SENSE 2 LR3C-14 Voltage Regulator BUS VOLTAGE SENSE VOLT REG FIELD 5 VOLTAGE REGULATOR FIELD EFIS 5 (All these items are powered from the #2 Skyview) SV-D1000 10" SKYVIEW DISPLAY 3.5amp SV-GPS-250 GPS MODULE 0.10amp SV-BAT-320 1.00 amp SV-ADAHRS-200 0.15amp SV-ARINC-429 0.10amp SV-KNOB-PANEL 0.07 amp SV-AP-PANEL 0.05 amp SV-EMS220 0.11amp USB WiFi ADAPTER 0.10amp FUEL PUMP 10 ELECTRIC FUEL PUMP PITOT 10 10.0amp max @ max heat START 5 STARTER SOLENOID GEAR CONTROL 5 Gear Controller circuitry 18 AWH wire GEAR HYD 30 Electro-Hydraulic pump for retractable gear actuation STROBE 10 WHELEN HDACF 01-0770028-05 LAND LIGHT 10 HID Landing Light plus two LED landing lights MISC LTS 5 INTERIOR LEDS AND OTHER LED MISC LIGHTS USB 10 USB CHARGER AND CIGARETTE LIGHTER SOCKET FUEL QTY 2 PRINCETON CAPACITANCE PROBES (two probes total) NAV 5 INCANDESCENT LIGHTS HEATED SEATS 10 FOUR SEATS IN THE AIRPLANE WILL BE HEATED. THIS CB IS FOR THE ACCESSORY CONTROL ONLY. THE SEAT HEATERS HAVE THEIR OWN 10 AMP MINI CB THAT IS CONNECTED TO THE GREEN BUS BAR. AVIONICS BUS YELLOW: The Avionics bus will be normally powered by the GREEN Bus through a dedicated Honeywell LT-001 ON/OFF switch. During abnormal operations after manual load shedding the Avionics Bus can be powered by the RED Bus through a dedicated Honeywell LT-001 ON/OFF switch. CB NAME AMP ITEM ON AVIONICS BUS BAR GARMIN COM 10 GARMIN GNS650 Comm Connector .45A continuous 5.66A Max when transmitting GARMIN NAV 7.5 GARMIN GNS650 Nav Connector .6A continuous 1.16A Max Main Connector 1.6A continuous 2.8A Max AUDIO 3 SL-15 0.350amp typ 1.5amp max XPNDR 5 SV-XPNDR-261 0.4amp ADS-B 5 SV-ADSB-470 0.2amp THANKS AGAIN!!! .. Cheers!!! Bill Hunter Mobile 408-464-1902 From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L. Nuckolls, III Sent: Wednesday, January 4, 2017 10:15 AM Subject: Re: AeroElectric-List: SD-20/SD-60 Question I am running a SD-60 and a LR3C-14 Voltage Regulator on one bus with its own battery and a SD-20 with its own LR3C-14 Voltage Regulator on the second bus with its own battery. The engine is a Lycoming IO-540. Okay, Figure Z-14 . . . QUESTION 1: I intend to operate my two electrical systems isolated with a bus tie that will be used for engine start only and then untied afterwards. What happens if I forget to untie the two busses after engine start and both the SD-60 and the SD-20 are providing current to the combined system? Do they share the load equally on the combined system? What happens should the system load reach 50 AMPS? Does the SD-20 simply max out at 20 AMPS and then the SD-60 picks up the rest of the 30 AMPS? Not necessarily. Both regulators should be set for optimal BATTERY maintenance (14.2 to 14.6 volts). It's practically impossible to set them to the same voltage. Hence, while paralleled, the alternator with the slightly higher setting will 'hog' the load until such time as it maxes out, bus voltage falls until the alternator with the lower set-point picks up the difference. QUESTION 2: If I do remember to untie the busses . . . How would this happen? If wired per the published drawing, the crossfeed contactor is automatically closed when a SPRING LOADED switch is moved to START position. This gets you two batteries for cranking while illuminating a CROSSFEED WARN light. When the engine starts, the switch is released, the contactor opens, the light goes out. Nothing to 'forget'. What happens to the single system when there is a temporary current spike on that isolated system? Example: Should the alternator be running at 90 percent of its capacity and then the electric landing gear hydraulic pump cycles and draws another 25-30 AMPS. Does the voltage regulator simply limit the alternator output to its max output of 60/20 AMPS and then the system draws down the battery during the short time the gear pump is active or does the voltage regulator deactivate the SD-60 requiring a reset? Not sure what the concern is here. First, how do you expect to normally load either alternator so heavily? Both sides should be designed to achieve 25% or so of headroom on the alternator for battery charging. But even if the inrush current from a pump motor exceeds an alternator's rated capacity, the bus voltage sags, the battery picks up the difference, and all returns to normal after the event . . . which is generally over in tens of milliseconds. No big deal. QUESTION 3: How much output does the SD-60 and the SD-20 really put out both at idle and at cruise RPM? I heard that the belt driven alternator will put out full production at low RPM however the SD-20 will only put out lower production at low RPM and only reach it's full rated production at max RPM? Generally true. Don't go by what you HEAR . . . go get the specs from the folks who design, manufacture, sell and support the systems. Generally speaking, B&C belt driven alternators DO run fast . . . unlike alternators deliberately slowed by installation of larger pulleys (to save bearings), the B&C alternators (and most others) produce a substantial fraction of rated output at taxi speeds. The SD-20 is mechanically crippled by installation on a drive pad with a max rpm on the order of 4K . . . LESS than minimum speed for full output from the 40A core from which the SD-20 is manufactured. Have offered that, it behooves every builder to KNOW what the in flight running loads are on ANY alternators. To KNOW what headroom is available to recharge the companion battery. To KNOW what energy levels are stored in any combination of batteries. Figure Z-14 offers a tall fire-wall against failures but it does not negate the value of discovering and understanding EVERYTHING there is to know about how all the pieces fit together along with the effect any single failure might have on in-flight systems operations. Bob . . . _____ This email has been checked for viruses by Avast antivirus software. www.avast.com ________________________________ Message 12 ____________________________________ Time: 03:32:44 PM PST US From: "William Hunter" Subject: RE: AeroElectric-List: EMI From Seat Heaters and Other Questions Thanks All for your time in contributing to this subject. I certainly came to the right place. DANGand I thought that a =9CBTU=9D was a form of currency changing because I see BTU on my utility bill and my currency changes from my account to the utility company account. .. Cheers!!! Bill Hunter From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Alec Myers Sent: Wednesday, January 4, 2017 4:31 AM Subject: Re: AeroElectric-List: EMI From Seat Heaters and Other Questions Someone has their units mixed up here. BTU is a measure of energy. Heaters are measured in BTU/hour. (Like the difference between joules and watts). 480W is 1638BTU/h, and 8000BTU/h is 2344W so the two figures given don't seem to agree. The former seems more reasonable than the latter for this unit. On Jan 3, 2017, at 23:50, Eric Page > wrote: On Jan 3, 2017, at 6:20 PM, William Hunter > wrote: QUESTION 4: How much heat would a small 12 VDC electric element heater system realistically put out? This is the one we have been discussing it is designed for a RV unit: http://www.my12voltstore.com/12_Volt_Ducted_Heater_p/sd12-4000.htm At the risk of being pedantic, I'm not sure how one would answer this other than to quote the product's specifications and explain the units. The description says this heater rated for 8,016 British Thermal Units (BTUs). A BTU is the amount of energy it takes to heat one pound of water (about 16 fl oz, or two cups) by one degree Fahrenheit. So, the heat energy this thing puts out could heat a 4-ton tank of water (approx 960 US gal) by one deg F in one hour. Or, to use numbers that are a bit more meaningful, heat about 96 gal of water by 10 deg F in one hour. Still not a very helpful comparison. The specs say it draws 480W (40A at 12V). It looks like the blower motor accounts for 15W (1.25A) of that total, which leaves 465W (38.75A) for the heating elements. That's a decent amount of heat, but compare that figure against a typical small domestic space heater that we're all familiar with: they're commonly rated at 1,500W. The first three search results for "hair dryer" on Amazon are rated at 1,875W! Recommendations vary between 20 and 60 BTU/sq ft for heating a home, depending on your climate region. If you assume a middle value of 40 BTU/sq ft, then 8,000 BTU would be about right for a 200 sq ft room (in a home insulated to code). Whether that kind of analysis translates to airplanes, or if 8,000 BTU is adequate for a light plane cockpit flying through freezing air are interesting questions. How warm is warm enough? Eric ________________________________ Message 13 ____________________________________ Time: 04:52:50 PM PST US Subject: Re: AeroElectric-List: EMI From Seat Heaters and Other Questions From: Charlie England Well....That's kinda comparing apples to kumquats. Ever driven a late model car with seat heaters? Hop in on a freezing cold day, crank the engine, and with the seat heaters on, your body will be warm before the engine coolant has gone up 2 degrees. All the heat goes directly to your body core. As an analogy, consider the radiant heaters used in a lot of workshops. As long as they are pointed at the worker, the worker stays reasonably warm even though the shop's air temp stays cold. I suspect that twins had Janitrol heaters long before heated seats were invented, or even a possibility (many generators from that era could barely keep up with the electrical demands of the instrument panel). And the current crop of cabin twins have them because those that can afford them expect them to offer all the comforts of home; hang the expense and inefficiency. Charlie On 1/4/2017 6:41 AM, Alec Myers wrote: > One might also point out that trying to heat a space from a 12v supply > is like filling a swimming pool from a garden hose. Don't expect too > much - there's a reason that where the aviation community can't use > exhaust muff heating systems (cabin twins, for instance) they don't > try electric, they use Janitrol heaters. > > On Jan 3, 2017, at 23:50, Eric Page > wrote: > > On Jan 3, 2017, at 6:20 PM, William Hunter > wrote: >> >> QUESTION 4: How much heat would asmall 12 VDC electric element >> heater system realistically put out? This is the one we have been >> discussing it is designed for a RV unit: >> http://www.my12voltstore.com/12_Volt_Ducted_Heater_p/sd12-4000.htm >> > > At the risk of being pedantic, I'm not sure how one would answer this > other than to quote the product's specifications and explain the units. > > The description says this heater rated for 8,016 British Thermal Units > (BTUs). A BTU is the amount of energy it takes to heat one pound of > water (about 16 fl oz, or two cups) by one degree Fahrenheit. > > So, the heat energy this thing puts out could heat a 4-ton tank of > water (approx 960 US gal) by one deg F in one hour. Or, to use > numbers that are a bit more meaningful, heat about 96 gal of water by > 10 deg F in one hour. Still not a very helpful comparison. > > The specs say it draws 480W (40A at 12V). It looks like the blower > motor accounts for 15W (1.25A) of that total, which leaves 465W > (38.75A) for the heating elements. That's a decent amount of heat, > but compare that figure against a typical small domestic space heater > that we're all familiar with: they're commonly rated at 1,500W. The > first three search results for "hair dryer" on Amazon are rated at 1,875W! > > Recommendations vary between 20 and 60 BTU/sq ft for heating a home, > depending on your climate region. If you assume a middle value of 40 > BTU/sq ft, then 8,000 BTU would be about right for a 200 sq ft room > (in a home insulated to code). > > Whether that kind of analysis translates to airplanes, or if 8,000 BTU > is adequate for a light plane cockpit flying through freezing air are > interesting questions. How warm is warm enough? > > Eric ________________________________ Message 14 ____________________________________ Time: 06:29:49 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: EMI From Seat Heaters and Other Questions > >I suspect that twins had Janitrol heaters long before heated seats >were invented, or even a possibility (many generators from that era >could barely keep up with the electrical demands of the instrument >panel). And the current crop of cabin twins have them because those >that can afford them expect them to offer all the comforts of home; >hang the expense and inefficiency. Janitrol and Southwind . . . both legacy icons in cabin comfort in the air and especially on the ground. I picked up an old Southwind heater at a garage sale some years back and was fascinated by the technology. MUCH simpler than the gas fired heater in my VW van. Dug up the patents on a few models . . . very slick. Used engine vacuum to 'suck' fuel, provide 'draft' and dispose of exhaust gasses. Glo plug for ignition. Really slick. Combustion fuel/air pathway totally closed. These were popular before my time but relatives spoke highly of them. McCollum's name appears on dozens of Southwind patents of that era . . . he was a prolific inventor/developer. My mentor (Ken Razak) and I puzzled over the practicality of adapting a similar technology to compact cabin heaters for the Ez series aircraft . . . using a venturi to produce operating vacuum. It appeared doable but not without a great deal of R&D . . . and the market was limited. All light twins use gas heaters 'cause you just can't get exhaust-muff heated air in from the wings. Further if the airplane is pressurized, the cabin air side of a gas heater lends itself to becoming part of the pressure vessel. Persons interested in reviewing this piece of automotive history are welcome to download the data package at: http://tinyurl.com/jy6potv Bob . . . --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ________________________________ Message 15 ____________________________________ Time: 09:18:18 PM PST US From: Buckaroo Banzai Subject: RE: AeroElectric-List: EMI From Seat Heaters and Other Questions Have you considered a door in the fresh air inlet to the air-oil cooler and an alternate air path to recycle cabin air through the air-oil cooler? -------------------------------------------- On Wed, 1/4/17, William Hunter wrote: Subject: RE: AeroElectric-List: EMI From Seat Heaters and Other Questions To: aeroelectric-list@matronics.com Date: Wednesday, January 4, 2017, 3:31 PM #yiv3929019256 #yiv3929019256 -- _filtered #yiv3929019256 {panose-1:2 4 5 3 5 4 6 3 2 4;} _filtered #yiv3929019256 {font-family:Calibri;panose-1:2 15 5 2 2 2 4 3 2 4;} #yiv3929019256 #yiv3929019256 p.yiv3929019256MsoNormal, #yiv3929019256 li.yiv3929019256MsoNormal, #yiv3929019256 div.yiv3929019256MsoNormal {margin:0in;margin-bottom:.0001pt;font-size:11.0pt;} #yiv3929019256 a:link, #yiv3929019256 span.yiv3929019256MsoHyperlink {color:#0563C1;text-decoration:underline;} #yiv3929019256 a:visited, #yiv3929019256 span.yiv3929019256MsoHyperlinkFollowed {color:#954F72;text-decoration:underline;} #yiv3929019256 span.yiv3929019256EmailStyle17 {color:windowtext;font-weight:normal;font-style:normal;} #yiv3929019256 span.yiv3929019256EmailStyle18 {color:black;font-weight:normal;font-style:normal;} #yiv3929019256 .yiv3929019256MsoChpDefault {font-size:10.0pt;} _filtered #yiv3929019256 {margin:1.0in 1.0in 1.0in 1.0in;} #yiv3929019256 div.yiv3929019256WordSection1 {} #yiv3929019256 Thanks All for your time in contributing to this subject. I certainly came to the right place. DANGand I thought that a BTU was a form of currency changing because I see BTU on my utility bill and my currency changes from my account to the utility company account... Cheers!!! Bill Hunter From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Alec Myers Sent: Wednesday, January 4, 2017 4:31 AM To: aeroelectric-list@matronics.com Subject: Re: AeroElectric-List: EMI From Seat Heaters and Other Questions Someone has their units mixed up here. BTU is a measure of energy. Heaters are measured in BTU/hour. (Like the difference between joules and watts). 480W is 1638BTU/h, and 8000BTU/h is 2344W so the two figures given don't seem to agree. The former seems more reasonable than the latter for this unit. On Jan 3, 2017, at 23:50, Eric Page wrote:On Jan 3, 2017, at 6:20 PM, William Hunter wrote:QUESTION 4: How much heat would a small 12 VDC electric element heater system realistically put out? This is the one we have been discussing it is designed for a RV unit: http://www.my12voltstore.com/12_Volt_Ducted_Heater_p/sd12-4000.htm At the risk of being pedantic, I'm not sure how one would answer this other than to quote the product's specifications and explain the units. The description says this heater rated for 8,016 British Thermal Units (BTUs). A BTU is the amount of energy it takes to heat one pound of water (about 16 fl oz, or two cups) by one degree Fahrenheit. So, the heat energy this thing puts out could heat a 4-ton tank of water (approx 960 US gal) by one deg F in one hour. Or, to use numbers that are a bit more meaningful, heat about 96 gal of water by 10 deg F in one hour. Still not a very helpful comparison. The specs say it draws 480W (40A at 12V). It looks like the blower motor accounts for 15W (1.25A) of that total, which leaves 465W (38.75A) for the heating elements. That's a decent amount of heat, but compare that figure against a typical small domestic space heater that we're all familiar with: they're commonly rated at 1,500W. The first three search results for "hair dryer" on Amazon are rated at 1,875W! Recommendations vary between 20 and 60 BTU/sq ft for heating a home, depending on your climate region. If you assume a middle value of 40 BTU/sq ft, then 8,000 BTU would be about right for a 200 sq ft room (in a home insulated to code). Whether that kind of analysis translates to airplanes, or if 8,000 BTU is adequate for a light plane cockpit flying through freezing air are interesting questions. How warm is warm enough? Eric ------------------------------------------------------------------------------------- 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.