---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sun 02/14/21: 17 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:01 PM - A 3 phase AC (Alternating Current) question (donjohnston) 2. 12:33 PM - Re: A 3 phase AC (Alternating Current) question (Charlie England) 3. 01:26 PM - Re: A 3 phase AC (Alternating Current) question (Robert L. Nuckolls, III) 4. 02:03 PM - Re: A 3 phase AC (Alternating Current) question (donjohnston) 5. 02:09 PM - Re: Re: A 3 phase AC (Alternating Current) question (Robert L. Nuckolls, III) 6. 02:09 PM - Re: A 3 phase AC (Alternating Current) question (user9253) 7. 02:09 PM - Re: A 3 phase AC (Alternating Current) question (donjohnston) 8. 02:19 PM - Re: Re: A 3 phase AC (Alternating Current) question (Robert L. Nuckolls, III) 9. 04:09 PM - Re: Re: A 3 phase AC (Alternating Current) question (Charlie England) 10. 04:10 PM - Re: A 3 phase AC (Alternating Current) question (Ernest Christley) 11. 04:25 PM - Re: Re: A 3 phase AC (Alternating Current) question (Ernest Christley) 12. 05:44 PM - DC Wiring Diagrams for SPA Panther LS (Rickifly) 13. 06:42 PM - Re: DC Wiring Diagrams for SPA Panther LS (Matthew S. Whiting) 14. 07:48 PM - Re: DC Wiring Diagrams for SPA Panther LS (Rickifly) 15. 09:24 PM - Re: DC Wiring Diagrams for SPA Panther LS (Jeff Luckey) 16. 09:52 PM - Re: Re: A 3 phase AC (Alternating Current) question (Robert L. Nuckolls, III) 17. 10:16 PM - Re: DC Wiring Diagrams for SPA Panther LS (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 12:01:47 PM PST US Subject: AeroElectric-List: A 3 phase AC (Alternating Current) question From: "donjohnston" Looking for some solutions on a project. I have a lathe/mill combo. I'm going to be upgrading it by replacing the motors and controlling them with VFD's. Space is tight and it occurred to me that if I could use one VFD to control the motors (never at the same time) that would simplify the installation. It would also save money since I would only need one VFD. :D But now the question is how to switch the VFD between the two motors? My first thought was a 3P2T switch. But I have not been able to find one rated for 230VAC and 1HP. It was suggested to use a contactor. But then I would need a low voltage source for the contactor with a switch for that power source and now it's no longer simplifying things. Any ideas? Read this topic online here: http://forums.matronics.com/viewtopic.php?p=500688#500688 ________________________________ Message 2 _____________________________________ Time: 12:33:48 PM PST US Subject: Re: AeroElectric-List: A 3 phase AC (Alternating Current) question From: Charlie England On 2/14/2021 2:00 PM, donjohnston wrote: > > Looking for some solutions on a project. > > I have a lathe/mill combo. I'm going to be upgrading it by replacing the motors and controlling them with VFD's. Space is tight and it occurred to me that if I could use one VFD to control the motors (never at the same time) that would simplify the installation. It would also save money since I would only need one VFD. :D > > But now the question is how to switch the VFD between the two motors? > > My first thought was a 3P2T switch. But I have not been able to find one rated for 230VAC and 1HP. It was suggested to use a contactor. But then I would need a low voltage source for the contactor with a switch for that power source and now it's no longer simplifying things. > > Any ideas? Contactors with 120VAC coils are used in thousands of devices. 1 HP should be easy to find; here's one rated at 30A per contact with a 120V coil: https://www.galco.com/buy/Deltrol-Controls/21011-84?source=googleshopping The vendor's spec sheet says '30A @ 30V DC', so it should handle 30A AC with no problem at all. I started by searching for '3pdt 30a 110v relay' Charlie -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ________________________________ Message 3 _____________________________________ Time: 01:26:16 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: A 3 phase AC (Alternating Current) question At 02:00 PM 2/14/2021, you wrote: > >Looking for some solutions on a project. > >I have a lathe/mill combo. I'm going to be upgrading it by >replacing the motors and controlling them with VFD's. Space is >tight and it occurred to me that if I could use one VFD to control >the motors (never at the same time) that would simplify the >installation. It would also save money since I would only need one VFD. :D > >But now the question is how to switch the VFD between the two motors? > >My first thought was a 3P2T switch. But I have not been able to >find one rated for 230VAC and 1HP. It was suggested to use a >contactor. But then I would need a low voltage source for the >contactor with a switch for that power source and now it's no longer >simplifying things. How often do you switch? Perhaps a simple drop-cord off each motor with a twist-lock plug could be used to mate the in-service motor with its power source. Bob . . . Un impeachable logic: George Carlin asked, "If black boxes survive crashes, why don't they make the whole airplane out of that stuff?" ________________________________ Message 4 _____________________________________ Time: 02:03:38 PM PST US Subject: AeroElectric-List: Re: A 3 phase AC (Alternating Current) question From: "donjohnston" > How often do you switch? Perhaps a simple > drop-cord off each motor with a twist-lock > plug could be used to mate the in-service > motor with its power source. Unfortunately, often enough that I'd rather not be swapping cables. That's just as bad as having to move the belts to change speeds. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=500691#500691 ________________________________ Message 5 _____________________________________ Time: 02:09:40 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: A 3 phase AC (Alternating Current) question At 04:03 PM 2/14/2021, you wrote: > > > > How often do you switch? Perhaps a simple > > drop-cord off each motor with a twist-lock > > plug could be used to mate the in-service > > motor with its power source. > > >Unfortunately, often enough that I'd rather not be swapping >cables. That's just as bad as having to move the belts to change speeds. Okay, then use a 2PDT switch or relay to switch two of the three leads between motors. Leave the 3rd wire always connected between VFD and both motors. No current can flow to the 'unpowered' motor unless at least TWO wires are connected. So leaving the third wire always connected will have no effect on system operations. Bob . . . Un impeachable logic: George Carlin asked, "If black boxes survive crashes, why don't they make the whole airplane out of that stuff?" ________________________________ Message 6 _____________________________________ Time: 02:09:52 PM PST US Subject: AeroElectric-List: Re: A 3 phase AC (Alternating Current) question From: "user9253" How about one of these switches: https://www.mouser.com/Electromechanical/Switches/Toggle-Switches/_/N-5g2jZ1yzvvqxZgjdhub?P=1z0z296Z1z0z20xZ1z0z2qcZ1z0yqrwZ1y8pmr4Z1y8ziurZ1y8ziusZ1z0z63x&Rl=5g2jZer5eZ1z0x8gwZ1z0x87nSGT&Ns=Current%20Rating|0 I assume that your VFD has an on-off switch controlling input power. Turn the input power off before switching the output power from one motor to the other. Then the switch will not even know that an inductive load is connected. If you operate a switch with no load on it, then it will handle a lot more current without damage. Even if a switch carries more current than its rating, it will not self destruct. But its life might be shortened, for example from 100,000 cycles to 5,000 cycles. A 3 phase, 240 volt motor will draw less than 4 amps according to this table: https://twcontrols.com/lessons/motors-horsepower-and-amps-of-230vac-and-460vac-3-phase-60hz-electric-motors -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=500693#500693 ________________________________ Message 7 _____________________________________ Time: 02:09:53 PM PST US Subject: AeroElectric-List: Re: A 3 phase AC (Alternating Current) question From: "donjohnston" Would I use one leg of the 230v supply to power the coil? (I haven't used a relay like this before) Read this topic online here: http://forums.matronics.com/viewtopic.php?p=500692#500692 ________________________________ Message 8 _____________________________________ Time: 02:19:44 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: A 3 phase AC (Alternating Current) question At 04:03 PM 2/14/2021, you wrote: > > > > How often do you switch? Perhaps a simple > > drop-cord off each motor with a twist-lock > > plug could be used to mate the in-service > > motor with its power source. > > >Unfortunately, often enough that I'd rather not be swapping >cables. That's just as bad as having to move the belts to change speeds. Plan C: Use two of these puppies https://tinyurl.com/y2dya9lc to effect your 2PDT switching. Only one contactor energized at a time. Then you can switch between motors with an itty-bitty toggle switch located remotely from the high-voltage-fat- wires. You'll also need a 24vac source to power the contactor coils https://tinyurl.com/yytcqyuy Bob . . . Un impeachable logic: George Carlin asked, "If black boxes survive crashes, why don't they make the whole airplane out of that stuff?" ________________________________ Message 9 _____________________________________ Time: 04:09:22 PM PST US Subject: Re: AeroElectric-List: Re: A 3 phase AC (Alternating Current) question From: Charlie England On 2/14/2021 4:08 PM, donjohnston wrote: > > Would I use one leg of the 230v supply to power the coil? > > (I haven't used a relay like this before) Yes. You do need a neutral, but anything wired to modern 'code' will have 3 phases, neutral and ground anyway. The switch is between one leg & the relay coil; the other coil terminal goes to neutral. Switch on would feed one output; switch off would feed the other. You'd still need some method of shutting down the whole system, of course. Do check on whether you have 'delta' or 'Y' configuration. With 'Y', you can pick any leg for the coil; with 'delta', you need to pick one of the 120 V legs; the 3rd leg will measure ~180 V to neutral. Charlie -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ________________________________ Message 10 ____________________________________ Time: 04:10:55 PM PST US From: Ernest Christley Subject: Re: AeroElectric-List: A 3 phase AC (Alternating Current) question connect the switch to relays?=C2- But, now you're talking six relays, so more complication. On Sunday, February 14, 2021, 03:02:43 PM EST, donjohnston wrote: m> Looking for some solutions on a project. I have a lathe/mill combo.=C2- I'm going to be upgrading it by replacing the motors and controlling them with VFD's.=C2- Space is tight and it occ urred to me that if I could use one VFD to control the motors (never at the same time) that would simplify the installation.=C2- It would also save money since I would only need one VFD. :D But now the question is how to switch the VFD between the two motors? My first thought was a 3P2T switch.=C2- But I have not been able to find one rated for 230VAC and 1HP.=C2- It was suggested to use a contactor.=C2 - But then I would need a low voltage source for the contactor with a swi tch for that power source and now it's no longer simplifying things. Any ideas? Read this topic online here: http://forums.matronics.com/viewtopic.php?p=500688#500688 - S - WIKI - - =C2- =C2- =C2- =C2- =C2- -Matt Dralle, List Admin. ________________________________ Message 11 ____________________________________ Time: 04:25:53 PM PST US From: Ernest Christley Subject: Re: AeroElectric-List: Re: A 3 phase AC (Alternating Current) question Plan D:=C2- If you want to keep it really simple.=C2- I just switched my mill to use an old treadmill motor.=C2- It required some machining to make thing fit up, but two treadmill motors could use the same controller w ith a DPDT switch.=C2- Another DPDT before that one could also give you r everse (but, you'll want to pin the flywheel if you do that).=C2- I've go t a video up showing what I did. https://rumble.com/vdm28n-powering-a-rong-fu-mill-with-a-treadmill-motor.ht ml?mref=fui8j&mc=c5hbl On Sunday, February 14, 2021, 05:20:29 PM EST, Robert L. Nuckolls, III wrote: At 04:03 PM 2/14/2021, you wrote: --> AeroElectric-List messageposted by: "donjohnston" > How often do you switch? Perhaps a simple > drop-cord off each motor with a twist-lock > plug could be used to mate the in-service > motor with its power source. Unfortunately, often enough that I'd rather not be swapping cables.=C2-Th at's just as bad as having to move the belts to changespeeds. =C2-Plan C: =C2-Use two of these puppieshttps://tinyurl.com/y2dya9lc =C2-to effect your 2PDT switching. Only one contactor =C2-energized at a time. =C2-Then you can switch between motors with an itty-bitty =C2-toggle switch located remotely from the high-voltage-fat- =C2-wires. =C2- You'll also need a 24vac source to power the =C2- contactor coils =C2-https://tinyurl.com/yytcqyuy =C2- Bob . . . =C2- Un impeachable logic: George Carlin asked, "If blackboxes =C2- survive crashes, why don't they make the whole airplane =C2- out of that stuff?" ________________________________ Message 12 ____________________________________ Time: 05:44:26 PM PST US From: Rickifly Subject: AeroElectric-List: DC Wiring Diagrams for SPA Panther LS Hello everyone, I created DC wiring diagrams for my Panther LS in Solidworks. EAA offers this 2D/3D cad program free for members. It is very easy to use and fairly intuitive. I based my electrical design on the Aeroelectric drawing files and B&C electric products. I don't mind sending these drawings out to use as a starting point in your own electrical designs. DM me for your preferred drawing format. .pdfs, .slddrw or .dwg formats. Notes: Based on the Aeroelectric Connection Handbook and drawing Z09A. The ignition and fuel systems are for a Corvair with Dual Ignition. The voltage Regulator is the new B&C Electric AVC-1. It features three functions in one and is Aircraft purpose built v the JohnDeere or Ford types of VR's. Scheme uses GRT Avionics as primary EFIS and MGL Avionics as a backup. Basic Day/Night VFR scheme. The lighting is FLYLEDS. The drawings are my draft design. I have not wired my airplane yet. They are not 100% the final scheme. Here are my concerns: 1. I chose to utilize relays to operate many of the devices that are on toggle switches (as long as the relay didn't draw more current than the actual devices). I can operate the devices by toggle switch without the intermediate relays, but wanted to see what everyone thought about how the S704-1 Relay is used in my schemes. 2. Inputs to the EIS device where the 4.8V excitation outputs are used to drive the sensors (oil, temp. pressure) and the way they are wired electrically for each circuit. Specifically how the Resistors are in series and parallel. 3. Use of flyback diodes on the relay coils and contactors, and the unidirectional diodes on the LED lighting circuits. Are they wired in the correct direction (anode and cathode)? 4. Headset mic and headphone jacks. Curious if I have these wired correctly. Thanks and many kind regards, Rick Gamble SPA Panther LS - under construction ________________________________ Message 13 ____________________________________ Time: 06:42:39 PM PST US From: "Matthew S. Whiting" Subject: Re: AeroElectric-List: DC Wiring Diagrams for SPA Panther LS Did you use the SolidWorks Electrical package or just the base mechanical pa ckage? I tried to install it a year or so ago and was able to install the b ase package just fine, but I could not get the electrical package to install .. Sent from my iPad > On Feb 14, 2021, at 8:53 PM, Rickifly wrote: > > =EF=BB > Hello everyone, > > I created DC wiring diagrams for my Panther LS in Solidworks. > EAA offers this 2D/3D cad program free for members. It is very easy to use and fairly intuitive. > > I based my electrical design on the Aeroelectric drawing files and B&C ele ctric products. I don't mind sending these drawings out to use as a starting point in your own electrical designs. DM me for your preferred drawing form at. .pdfs, .slddrw or .dwg formats. > > Notes: > Based on the Aeroelectric Connection Handbook and drawing Z09A. > The ignition and fuel systems are for a Corvair with Dual Ignition. > The voltage Regulator is the new B&C Electric AVC-1. It features three fun ctions in one and is Aircraft purpose built v the JohnDeere or Ford types of VR's. > Scheme uses GRT Avionics as primary EFIS and MGL Avionics as a backup. > Basic Day/Night VFR scheme. The lighting is FLYLEDS. > The drawings are my draft design. I have not wired my airplane yet. They a re not 100% the final scheme. > > Here are my concerns: > 1. I chose to utilize relays to operate many of the devices that are on to ggle switches (as long as the relay didn't draw more current than the actual devices). I can operate the devices by toggle switch without the intermedia te relays, but wanted to see what everyone thought about how the S704-1 Rela y is used in my schemes. > 2. Inputs to the EIS device where the 4.8V excitation outputs are used to d rive the sensors (oil, temp. pressure) and the way they are wired electrical ly for each circuit. Specifically how the Resistors are in series and parall el. > 3. Use of flyback diodes on the relay coils and contactors, and the unidir ectional diodes on the LED lighting circuits. Are they wired in the correct direction (anode and cathode)? > 4. Headset mic and headphone jacks. Curious if I have these wired correctl y. > > Thanks and many kind regards, > Rick Gamble > SPA Panther LS - under construction > > > > > ________________________________ Message 14 ____________________________________ Time: 07:48:09 PM PST US From: Rickifly Subject: Re: AeroElectric-List: DC Wiring Diagrams for SPA Panther LS I am using the basic student edition of Solidworks. I may invest in the full version if I keep modeling in 3D. It is very easy to learn and now I want a new graphics card and more processors, for those realistic looking models. I completed my first parts in 3D for the airplane: the Panel and the GRT Sport EFIS. And was able to send the Avionics Panel with cutouts modeled part drawing to EMachineShop for a quote. They accept Solidworks modeled parts without converting them to a step file or machine file. The electrical package would be great to have as an add-in. The automated features are very cool. For this little airplane I prob could finish point to points in short order... The Solidworks 2021 version seems better than previous years BTW. Rick On Sun, Feb 14, 2021 at 8:48 PM Matthew S. Whiting wrote: > Did you use the SolidWorks Electrical package or just the base mechanical > package? I tried to install it a year or so ago and was able to install > the base package just fine, but I could not get the electrical package to > install. > > Sent from my iPad > > On Feb 14, 2021, at 8:53 PM, Rickifly wrote: > > =EF=BB > > Hello everyone, > > I created DC wiring diagrams for my Panther LS in Solidworks. > EAA offers this 2D/3D cad program free for members. It is very easy to us e > and fairly intuitive. > > I based my electrical design on the Aeroelectric drawing files and B&C > electric products. I don't mind sending these drawings out to use as a > starting point in your own electrical designs. DM me for your preferred > drawing format. .pdfs, .slddrw or .dwg formats. > > Notes: > Based on the Aeroelectric Connection Handbook and drawing Z09A. > The ignition and fuel systems are for a Corvair with Dual Ignition. > The voltage Regulator is the new B&C Electric AVC-1. It features three > functions in one and is Aircraft purpose built v the JohnDeere or Ford > types of VR's. > Scheme uses GRT Avionics as primary EFIS and MGL Avionics as a backup. > Basic Day/Night VFR scheme. The lighting is FLYLEDS. > The drawings are my draft design. I have not wired my airplane yet. They > are not 100% the final scheme. > > Here are my concerns: > 1. I chose to utilize relays to operate many of the devices that are on > toggle switches (as long as the relay didn't draw more current than the > actual devices). I can operate the devices by toggle switch without the > intermediate relays, but wanted to see what everyone thought about how th e > S704-1 Relay is used in my schemes. > 2. Inputs to the EIS device where the 4.8V excitation outputs are used to > drive the sensors (oil, temp. pressure) and the way they are wired > electrically for each circuit. Specifically how the Resistors are in seri es > and parallel. > 3. Use of flyback diodes on the relay coils and contactors, and the > unidirectional diodes on the LED lighting circuits. Are they wired in th e > correct direction (anode and cathode)? > 4. Headset mic and headphone jacks. Curious if I have these wired > correctly. > > Thanks and many kind regards, > Rick Gamble > SPA Panther LS - under construction > > > > > ________________________________ Message 15 ____________________________________ Time: 09:24:21 PM PST US From: Jeff Luckey Subject: Re: AeroElectric-List: DC Wiring Diagrams for SPA Panther LS Hey Rick, Nice drawings! Regarding Relays: Relays can be used for all sorts of things.=C2- Two of the most common us es are:1. To use a small current to control a big current2. To implement sp ecial switching logic (like your trim control) It looks like several of the things you are controlling with relays are pre tty low current (less than 10 amp) so putting a relay in the circuit is sup erfluous. Those relays just add complexity, parts count, number of terminat ions, weight, etc without adding any real value.=C2- You'd be better-off using switches directly for the fuel pumps & auto pilot and probably the av ionics relay (also consider that a single avionics switch is a possible sin gle point of failure).=C2-=C2- That's what I saw with a quick glance at your drawings.=C2- I did not stu dy them. -Jeff On Sunday, February 14, 2021, 07:57:32 PM PST, Rickifly wrote: I am using the basic student edition of Solidworks. I may invest in the fu ll version if I keep modeling in 3D. It is very easy to learn and now I wan t a new graphics card and more processors, for those realistic looking mode ls. I completed my first parts in 3D for the airplane: the Panel and the GR T Sport EFIS.=C2- And was able to send the Avionics Panel with cutouts mo deled part drawing to EMachineShop for a quote.=C2- They accept Solidwork s modeled parts without converting them to a step file or machine file. =C2 -The electrical package would be great to have as an add-in.=C2- The au tomated features are very cool.=C2- For this little airplane I prob could finish point to points in short order...The Solidworks 2021 version seems better than previous years BTW.Rick=C2- On Sun, Feb 14, 2021 at 8:48 PM Matthew S. Whiting wrote: Did you use the SolidWorks Electrical package or just the base mechanical p ackage?=C2- I tried to install it a year or so ago and was able to instal l the base package just fine, but I could not get the electrical package to install. Sent from my iPad On Feb 14, 2021, at 8:53 PM, Rickifly wrote: =EF=BB Hello everyone,=C2- I created DC wiringdiagrams for my Panther LS in Solidworks.=C2-EAA offer s this 2D/3D cad programfree for members. It is very easy to use and fairly intuitive. I based my electrical design on the Aeroelectricdrawing files and B&C elect ric products. I don't mind sending these drawings out to use as a starting point in yourown electrical designs. DM me for your preferred drawing forma t. .pdfs, .slddrwor .dwg formats. Notes: Based on the Aeroelectric Connection Handbook anddrawing Z09A.=C2- The ignition and fuel systems are for a Corvairwith Dual Ignition. The voltage Regulator is the new B&C ElectricAVC-1. It features three funct ions in one and is Aircraft purpose built v theJohnDeere or Ford types of V R's. Scheme uses GRT Avionics as primary EFIS and MGLAvionics as a backup. Basic Day/Night VFR scheme. The lighting isFLYLEDS. The drawings are my draft design. I have not wiredmy airplane yet. They are not 100% the final scheme. Here are=C2-my concerns:1. I chose to utilize relays to operate many of t hedevices that are on toggle switches (as long as the relay didn't=C2-dra w more current than the actual=C2-devices). I can operate the devices by toggleswitch without the intermediate relays, but wanted to see what everyo ne thought about how the S704-1 Relay is used in my schemes.=C2- 2. Inputs to the EIS device where the 4.8V excitation=C2-outputs are used to drive the sensors (oil, temp. pressure) and the way they are wired elec trically for each circuit. Specifically how the Resistors are in series and parallel.=C2-=C2-3. Use of flyback diodes on the relay coils and conta ctors, and the unidirectional diodes on the LED lighting circuits.=C2- Ar e they wired in the correct direction (anode and cathode)?4. Headset mic an d headphone jacks. Curious if I have these wired correctly.=C2- Thanks and many kind regards,Rick GambleSPA Panther LS - under construction ________________________________ Message 16 ____________________________________ Time: 09:52:15 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: A 3 phase AC (Alternating Current) question At 04:08 PM 2/14/2021, you wrote: > >Would I use one leg of the 230v supply to power the coil? > >(I haven't used a relay like this before) > > See attached . . . Bob . . . Un impeachable logic: George Carlin asked, "If black boxes survive crashes, why don't they make the whole airplane out of that stuff?" ________________________________ Message 17 ____________________________________ Time: 10:16:50 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: DC Wiring Diagrams for SPA Panther LS Here are my concerns: 1. I chose to utilize relays to operate many of the devices that are on toggle switches (as long as the relay didn't draw more current than the actual devices). I can operate the devices by toggle switch without the intermediate relays, but wanted to see what everyone thought about how the S704-1 Relay is used in my schemes. What advantage is secured by doing this? It adds weight and complexity. Why an 'avionics switch'? It too adds complexity and offers single point of failure for all avionics. A Boeing 787 doesn't have one . . . they were slightly useful in 1965 but totally worthless by 1980. 2. Inputs to the EIS device where the 4.8V excitation outputs are used to drive the sensors (oil, temp. pressure) and the way they are wired electrically for each circuit. Specifically how the Resistors are in series and parallel. Are these resistors required per manufacturer's installation instructions? There are better ways to 'package' these. Threaded fastener terminal strips are kind of a last resort. Bob . . . Un impeachable logic: George Carlin asked, "If black boxes survive crashes, why don't they make the whole airplane out of that stuff?" ------------------------------------------------------------------------------------- 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.