Van's Air Force
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fuses v circuit breakers
- Thread starter tonyjohnson
- Start date
Norman CYYJ
Well Known Member
If you have deep pockets circuit breakers are the way to go, if your pockets are even deeper use circuit breakers that you can pull off and for really deep pockets use toggle circuit breakers. But all joking aside fuses are more reliable, less weight and much cheaper. I guess Van's and Piper and Cessna go to breakers for convienence and a modern look. What ever way you go you are protecting the wire to a device, not the device itself.
Captain_John
Well Known Member
George, I gotta say... I think we (and I mean everyone) are all pretty much on the same page here with all of our thoughts. This is a good thing.
I am not always "on board" with the new designs. Especially the new AFCI's. I am a traditional Yankee and new things are not immediately embraced by me. I take a wait and see attitude ALOT. With regard to the way these types of things make it to market are not to my liking. I have a verbal tirade about this which is too long and too far OT to go into here. If you care to chat about it, www.skype.com me sometime and we can chat.
The AFCI's were NOT WITHOUT their problems when initially introduced and can very easily nuisance trip or not serve their purpose when needed. If that is the case, I prefer NOT to use them. We are being REQUIRED to install them in residential occupancies now and I am sure that they will follow the way of the GFCI's being required in more and more locations as supplies and laws increase in magnitude.
Tony, very nice drop down panel! I will implement a similar feature!
CJ
I am not always "on board" with the new designs. Especially the new AFCI's. I am a traditional Yankee and new things are not immediately embraced by me. I take a wait and see attitude ALOT. With regard to the way these types of things make it to market are not to my liking. I have a verbal tirade about this which is too long and too far OT to go into here. If you care to chat about it, www.skype.com me sometime and we can chat.
The AFCI's were NOT WITHOUT their problems when initially introduced and can very easily nuisance trip or not serve their purpose when needed. If that is the case, I prefer NOT to use them. We are being REQUIRED to install them in residential occupancies now and I am sure that they will follow the way of the GFCI's being required in more and more locations as supplies and laws increase in magnitude.
Tony, very nice drop down panel! I will implement a similar feature!
CJ
jlfernan
Well Known Member
There's been a lot of debate between CB's and fuses and all that it's done is confuse me even more!! No one has yet mentioned(except me many posts ago) switch breakers. They're more costly, but seem to free up plenty of room. Someone, anyone, please chime in with your opinion of these.
Switch breakers
Jorge,
Switch breakers are good too, and are used extensively by Van's. They are expensive, and don't offer the redundancy of a switch and a CB for turning off a circuit. The good news is, they aren't hidden out of sight like most fuse panels.
Take a look at Kahuna's post about the desirability of isolating the BMA and
GR for software re-boot. Ask the guys promoting fuses if that can be done with their system.
Jorge,
Switch breakers are good too, and are used extensively by Van's. They are expensive, and don't offer the redundancy of a switch and a CB for turning off a circuit. The good news is, they aren't hidden out of sight like most fuse panels.
Take a look at Kahuna's post about the desirability of isolating the BMA and
GR for software re-boot. Ask the guys promoting fuses if that can be done with their system.
Yukon said:
Since this keeps coming up with the notion of "preflighting the fuse block", I have to ask....does anyone here take apart their circuit breakers and check the contacts for corrosion or the mechanism for wear as part of their preflight? Does anyone even go around a check that every breaker is in? I sure don't. I turn the system on and perform my check...if it works, the breaker's in. Same with fuses.
What's the big deal anyhow? You ARE allowed to mount a fuse box visibly if you want but most people hide them away so it doesn't take up panel space.
Yukon said:
Use a switch.
Even better, put that one device on a Klixon pullable CB. There's no law that says you can't use a combination of fuses and breakers knowing that each have advantages and disadvantages and each are appropriate (and better) in different circumstances.
Jekyll,Jekyll said:
The status panel uses dual color LEDs, so voltage present indicates green, and voltage absent indicates red. Therefore, you get a positive indication of a good fuse, and you get a positive indication of a blown fuse. Very simple. Of course, there is always the question of the integrity of the wire used to connect to the fuse itself, but every self test system has limitations.
I had a lot of other ideas as to how to do this panel to make it better (blinking LEDs, enable/disable, audio, etc.), but as with any project I found the list growing out of proportion to the actual need, which was to simply show the status of all of the fuses. So, I limited the scope of the panel to my original needs, and it does what it is supposed to do.
Tracy.
Jekyll,
It is a simple board with 3 CMOS hex inverters, which supports 18 inputs. CMOS allows 2-18 volt inputs. Each input goes to the green side of a dual color LED and each output goes to the red side of a dual color LED. When the input is high, the output of the inverter is low. This turns on the green side and turns off the red side. I have the appropriate resistors to ensure that the input is pulled low when there is no voltage on the input.
Tracy.
It is a simple board with 3 CMOS hex inverters, which supports 18 inputs. CMOS allows 2-18 volt inputs. Each input goes to the green side of a dual color LED and each output goes to the red side of a dual color LED. When the input is high, the output of the inverter is low. This turns on the green side and turns off the red side. I have the appropriate resistors to ensure that the input is pulled low when there is no voltage on the input.
Tracy.
Dad's RV-10
Well Known Member
Just curios...does the Nuckolls book describe how to design a system should you prefer to go the all-breaker route?
Or does he just discuss his preferred method of using auto-style fuses?
By the way, it's surprising how much pertinent information you can find about Bob by Googling "Bob Knuckles!"
TIA.
Brad
Or does he just discuss his preferred method of using auto-style fuses?
By the way, it's surprising how much pertinent information you can find about Bob by Googling "Bob Knuckles!"
TIA.
Brad
gmcjetpilot
Well Known Member
Knuckles?
Even Bob's buddies B&C specialities sell CB's and brass strap to gang the CB's together.
The obvious difference is Bob like to hide the fuse block under the panel or near the battery. CB's in general need to be located in the instrument panel. In a RV the difference in location of CB's and fuse block is measure in inches, but there is a physical differnce where the protection is located.
The only substantive change in wiring comes from how to handle the "B-Lead" (battery lead or alternator output) from the alternator to the battery.
Bob suggest using a big "Bussman" fuse hidden and inaccessible under the cowl and wire it direct to the battery (assuming the battery is located under the cowl).
Bob's "B-lead" wiring
ALT (+B)-------(Bussman fuse)----BAT--[firewall]--BUSS
The alternative and traditional, common most prolific way to wire the "B-lead", as in 1000's of Cessna's/Piper's and most production GA airplanes, is to run the "B-lead" to a panel mounted CB and than to the main buss. Bob's philosophy is if the alternator "B-lead" protection (fuse) blows, you don't need or want or need to reset it, as long as you have planned for that eventuality. Bob does that by extra "alternate" wiring direct to the battery. There is more than one way to skin a cat.... and each way is subject to debate.
Traditional "B-lead" wiring
ALT (+B)-----[firewall]-----(CB panel mounted )----BUSS
------------------------------------------------------.^
------------------------------------------------------.^
BAT----------[ firewall]-------------------------------^
The advantage of Bob's method is you don't need to run the "B-lead" in parallel with the battery wire and thru the firewall an extra 2 feet to a panel mounted CB. Bob claims this "B-lead" is noisy, but I disagree. If you have electrical noise you have a problem. Modern alterantors, solid state voltage regulators and good grounds makes modern electrical systems quite, not where you wire the "B-lead".
Nothing wrong with Bob's idea but it is controversial that you can't reset the alternator in flight. As far as big fuses "under the hood", that is common practice in cars, where there is a local fues block under the hood, including some of the high amp protection.
So there is a little difference in the wires. Most of the difference is where the "B-lead" protection is. There is also a little difference in location of wiring circuit protection, since you can hide the fuses. Overall the difference is small from a wiring standpoint.
I get your question but there is little or no additional design difference, except that you substitute the CB for fuel block. Circuit protection is circuit protection and needs to be located where it's needed, with a little exception.Air UPSer said:
Even Bob's buddies B&C specialities sell CB's and brass strap to gang the CB's together.
The obvious difference is Bob like to hide the fuse block under the panel or near the battery. CB's in general need to be located in the instrument panel. In a RV the difference in location of CB's and fuse block is measure in inches, but there is a physical differnce where the protection is located.
The only substantive change in wiring comes from how to handle the "B-Lead" (battery lead or alternator output) from the alternator to the battery.
Bob suggest using a big "Bussman" fuse hidden and inaccessible under the cowl and wire it direct to the battery (assuming the battery is located under the cowl).
Bob's "B-lead" wiring
ALT (+B)-------(Bussman fuse)----BAT--[firewall]--BUSS
The alternative and traditional, common most prolific way to wire the "B-lead", as in 1000's of Cessna's/Piper's and most production GA airplanes, is to run the "B-lead" to a panel mounted CB and than to the main buss. Bob's philosophy is if the alternator "B-lead" protection (fuse) blows, you don't need or want or need to reset it, as long as you have planned for that eventuality. Bob does that by extra "alternate" wiring direct to the battery. There is more than one way to skin a cat.... and each way is subject to debate.
Traditional "B-lead" wiring
ALT (+B)-----[firewall]-----(CB panel mounted )----BUSS
------------------------------------------------------.^
------------------------------------------------------.^
BAT----------[ firewall]-------------------------------^
The advantage of Bob's method is you don't need to run the "B-lead" in parallel with the battery wire and thru the firewall an extra 2 feet to a panel mounted CB. Bob claims this "B-lead" is noisy, but I disagree. If you have electrical noise you have a problem. Modern alterantors, solid state voltage regulators and good grounds makes modern electrical systems quite, not where you wire the "B-lead".
Nothing wrong with Bob's idea but it is controversial that you can't reset the alternator in flight. As far as big fuses "under the hood", that is common practice in cars, where there is a local fues block under the hood, including some of the high amp protection.
So there is a little difference in the wires. Most of the difference is where the "B-lead" protection is. There is also a little difference in location of wiring circuit protection, since you can hide the fuses. Overall the difference is small from a wiring standpoint.
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f1rocket
Well Known Member
If you using alternator controllers, they "CAN" be reset in flight and these should trip before the Bussman does. They are the only C/Bs in my cockpit. If I get a short that blows an 60 AMP fuse, I sure as heck do not want to turn it back on in flight until I can check it out. That's a pretty hefty load and quite capable of starting a fire!gmcjetpilot said:
Kevin Horton
Well Known Member
This "requirement" is a red herring. First, it is a FAR Part 23 requirement, i.e. it applies to type-certificated aircraft. It does not apply to RVs.Red said:
Second, the requirement reads:
23.1357(d) If the ability to reset a circuit breaker or replace a fuse is essential to safety in flight, that circuit breaker or fuse must be so located and identified that it can be readily reset or replaced in flight.
But, if you have a system that is essential to safety in flight (for example, an EFIS, if you fly IFR), then you also need to consider the case of that system simply failing, with the failure not caused by a blown fuse or CB.
How do you ensure that you can safely complete the flight if the EFIS fails and you are IFR? You do this by having suitable backup instruments. As soon as you add the backup instruments, the EFIS is no longer essential to safety in flight, and you don't have to worry about being able to access the fuses or CBs.
gmcjetpilot
Well Known Member
I can't disagree
There could be a surge where the alternator pops the CB, which is not a dead short and could be restored. I know of one case where this happened, granted there where mitigating factors.
Bottom line there's nothing wrong with the IF IT POPS/BLOWS LEAVE IT ALONE philosophy. I don't personally buy there is never a need to reset a Fuse or CB, but than it depends on so many factors, mission and system redundancy. I have had may be two or three CB's pop over the years from normal operations (in larger planes). They tend to be large current users like window or prop heat or electric motors/pumps. It happens. Still there is the PIC option to not reset even once. I personally use and like a pull-able "B-lead" CB to assure or at least help isolate the alternator out-put if needed (aka B-lead disconnect). Again there's nothing wrong with Bob's idea, but somehow Bob makes it sound like it's the ONLY WAY. I personally like the control and ability to open circuits individually if needed. Probably will never need to do that in a RV, but it makes me happy. Say a radio smokes and is not controlled with the on off switch. You could turn everything off with the master or avionics switch I guess. Either way (philosophies) are safe and reasonable approaches. No mea culpa bro.
That is your prerogative Captain Randy and sounds fine to me. However sometimes the 60 amp CB pops because you are running near the rated output for some normal reason. After "load shedding" you can reset the CB.f1rocket said:
There could be a surge where the alternator pops the CB, which is not a dead short and could be restored. I know of one case where this happened, granted there where mitigating factors.
One of my students many years ago was going on one of her solo cross country flights. Well she made one mistake and turned the battery on and accidentally left the ALT off (Cessna split switch). She took off enroute and did not note the discharge, mistake two. Never the less I can see it happening to anyone. She realized her error and proceed to turn the ALT on. Because the battery was now discharged it demanded a large current, it popped the CB with the combined load of lights, radios and battery charging. She did not think to "load shed" first, before resetting the CB.
Well from then on she was perfect. She noted the CB pop, let cool, reset once and left it out when it popped out the 2nd time. She did a 180 and than did an electrical load shed to save the remaining battery. Nearing the airport she powered the comm up and landed without further incidence. Yes she should have turned the ALT on first; Yes she should have checked for charge right after start; Yes she probably would have been successful resetting the CB if she would have turned the strobes and avionics off first, before turning the ALT on, however I never taught her this. To be sure from than on I went over this in detail with all students using Machado's water flow analogy.
Well from then on she was perfect. She noted the CB pop, let cool, reset once and left it out when it popped out the 2nd time. She did a 180 and than did an electrical load shed to save the remaining battery. Nearing the airport she powered the comm up and landed without further incidence. Yes she should have turned the ALT on first; Yes she should have checked for charge right after start; Yes she probably would have been successful resetting the CB if she would have turned the strobes and avionics off first, before turning the ALT on, however I never taught her this. To be sure from than on I went over this in detail with all students using Machado's water flow analogy.
Bottom line there's nothing wrong with the IF IT POPS/BLOWS LEAVE IT ALONE philosophy. I don't personally buy there is never a need to reset a Fuse or CB, but than it depends on so many factors, mission and system redundancy. I have had may be two or three CB's pop over the years from normal operations (in larger planes). They tend to be large current users like window or prop heat or electric motors/pumps. It happens. Still there is the PIC option to not reset even once. I personally use and like a pull-able "B-lead" CB to assure or at least help isolate the alternator out-put if needed (aka B-lead disconnect). Again there's nothing wrong with Bob's idea, but somehow Bob makes it sound like it's the ONLY WAY. I personally like the control and ability to open circuits individually if needed. Probably will never need to do that in a RV, but it makes me happy.
Say a radio smokes and is not controlled with the on off switch. You could turn everything off with the master or avionics switch I guess. Either way (philosophies) are safe and reasonable approaches. No mea culpa bro.
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gmcjetpilot
Well Known Member
Same page different preferences
1) Make ever possible effort to make sure it is not subject to nuisance trip/blowing per the above paragraph (proper sizing of circuit protection and wiring).
2) You have designed you system to not be flight critical for a blown B-lead fuse based on mission, equip and redundancy (say extra battery capacity or second alternator for example, if needed say for a IFR mission or electrically dependant engine).
We are on the same page, just different preferences. G
I agree proper sizing of CB or Fuse and wiring is key. Excellent point. Just that sometimes 60 amp "rated" alternators sometimes can produce 80 amps, but I am stretching. You make a great point, and again I say there is nothing WRONG with using a hidden fuse if you do two things:f1rocket said:
1) Make ever possible effort to make sure it is not subject to nuisance trip/blowing per the above paragraph (proper sizing of circuit protection and wiring).
2) You have designed you system to not be flight critical for a blown B-lead fuse based on mission, equip and redundancy (say extra battery capacity or second alternator for example, if needed say for a IFR mission or electrically dependant engine).
We are on the same page, just different preferences. G
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Hail VAF members!
In MY opinion, if I get the chance to build my own Vans Areoplane, the areoplane cockpit would contain pullable CB's for every circuit.
In MY experience, aircraft quality pullable circuit breakers are very reliable ( and you CAN test them!)
Let me start right away to say that if a builder/pilot is satisfied with fuses only, then I respect that opinion. My post here is meant to answer the original question in a way that has yet been answered.
Overall, CB's give the PIC CHOICES. Many issues have already been addresses, but I can add a few more.
1) Gremlins! So you have a Nifty Spiffy Vans Areoplane built yourself. In fact it has X Y and Z super dooper equipment on it. The local guys are all running variations of A B and C equipment without any issues all on fused circuits. ( Again this is fine, there is nothing wrong with good circuit design using fuses.) However, it just happens that no EE has been paid to evaluate the the fluctuations for normal output noise of the source, not to mention all the possible backfeed noise as each equipment draws the power it needs ... ( never mind the possibly high induce currents from RF radiation coming from three dimensional sources causing intermodulation in circuits ( never mind the thermal changes in electronic values.. ( never mind the changes caused by atmospheric changes) ...
Yeap, fuses and CB's can open when just the 1 in a million, less odds then the lottery, set of conditions occur.
Jump starting shouldn't cause any problems. If no other issues are found, I'm going to have to blame Gremlins!
2) Fire! Very often an electrical fire CAN occur with low currents. In fact, currents that are LOWER then the rated fuse. Lets just say you raised your flaps, and checked for "up" ... then noticed a slight trace of smoke coming from the joint nearest the flap motor. If this circuit is on a CB you just pull the fuse. If not .... I hope you are on the ground, and not climbing back out after a touch-n-go.
3) Smoke! Ok, so it happend, the transponder decided to take a lunch break, smoke poured out, and the circuit blew. With a CB, the PIC has a choice; with a fuse, no choice. In modern electronics, there are many, many circuits in each "box". The higher current circuit in that particular transponder might be for Mode IV. After the smoke clears, resetting the CB MAY allow all other modes to still function. Unless the PS for the unit dies, it is unlikely that a single circuit failure will cause complete failure of the unit. Resetting the CB for the device may restore partial functionality.
4)Operating Systems. More and more systems are run with software. You might have laughed about the "gremlins" comment above with hardware, but certainly can't ignore the "gremlins" in software. Anything that has a BIOS, or can be FLASHED, should be on its own pullable CB. There is no reason to take down the entire avionics bus just to cycle and reboot the GPS.
And finally, as the PIC, EXTREME Caution needs to be taken when making the decision to reset a circuit. Though my information above promotes having the ABILITY to perform a reset, ultimately if the device is NOT needed, it is of course generally safer to leave the circuit open.
I hope this is as clear as mud.
Good luck,
tonyjohnson said:
n468ac said:
In MY opinion, if I get the chance to build my own Vans Areoplane, the areoplane cockpit would contain pullable CB's for every circuit.
In MY experience, aircraft quality pullable circuit breakers are very reliable ( and you CAN test them!)
Let me start right away to say that if a builder/pilot is satisfied with fuses only, then I respect that opinion. My post here is meant to answer the original question in a way that has yet been answered.
Overall, CB's give the PIC CHOICES. Many issues have already been addresses, but I can add a few more.
1) Gremlins! So you have a Nifty Spiffy Vans Areoplane built yourself. In fact it has X Y and Z super dooper equipment on it. The local guys are all running variations of A B and C equipment without any issues all on fused circuits. ( Again this is fine, there is nothing wrong with good circuit design using fuses.) However, it just happens that no EE has been paid to evaluate the the fluctuations for normal output noise of the source, not to mention all the possible backfeed noise as each equipment draws the power it needs ... ( never mind the possibly high induce currents from RF radiation coming from three dimensional sources causing intermodulation in circuits ( never mind the thermal changes in electronic values.. ( never mind the changes caused by atmospheric changes) ...
Yeap, fuses and CB's can open when just the 1 in a million, less odds then the lottery, set of conditions occur.
Jump starting shouldn't cause any problems. If no other issues are found, I'm going to have to blame Gremlins!
2) Fire! Very often an electrical fire CAN occur with low currents. In fact, currents that are LOWER then the rated fuse. Lets just say you raised your flaps, and checked for "up" ... then noticed a slight trace of smoke coming from the joint nearest the flap motor. If this circuit is on a CB you just pull the fuse. If not .... I hope you are on the ground, and not climbing back out after a touch-n-go.
3) Smoke! Ok, so it happend, the transponder decided to take a lunch break, smoke poured out, and the circuit blew. With a CB, the PIC has a choice; with a fuse, no choice. In modern electronics, there are many, many circuits in each "box". The higher current circuit in that particular transponder might be for Mode IV. After the smoke clears, resetting the CB MAY allow all other modes to still function. Unless the PS for the unit dies, it is unlikely that a single circuit failure will cause complete failure of the unit. Resetting the CB for the device may restore partial functionality.
4)Operating Systems. More and more systems are run with software. You might have laughed about the "gremlins" comment above with hardware, but certainly can't ignore the "gremlins" in software. Anything that has a BIOS, or can be FLASHED, should be on its own pullable CB. There is no reason to take down the entire avionics bus just to cycle and reboot the GPS.
And finally, as the PIC, EXTREME Caution needs to be taken when making the decision to reset a circuit. Though my information above promotes having the ABILITY to perform a reset, ultimately if the device is NOT needed, it is of course generally safer to leave the circuit open.
I hope this is as clear as mud.
Good luck,
dan
Well Known Member
Smoke or fire due to something electric, since my airplane has fuses, I have ONE SIMPLE TASK to perform: TURN THE MASTER OFF. That's it. No fiddling with breakers or trying to figure out what's causing it. Just flip the switch, done deal.
Reducing "choices" or options for the PIC is not necessarily a bad thing in my book. By reducing choices, workload in an emergency situation is simplified. The fewer choices I have to make, the less likely I'm gonna slam into terrain while distracted trying to troubleshoot something...yikes...which breaker do I pull now?!
Reducing "choices" or options for the PIC is not necessarily a bad thing in my book. By reducing choices, workload in an emergency situation is simplified. The fewer choices I have to make, the less likely I'm gonna slam into terrain while distracted trying to troubleshoot something...yikes...which breaker do I pull now?!
Hail RAF member jlfernan,
Switch breakers are a really neat idea. I just wonder, "WHY?"
The answer may very well be, "to free up plenty of room".
In MY opinion, I do not like the idea of combining "on/off" switch function with "circuit protection".
There is a distinct difference between the two choices used everywhere else.
If you run the 30 cords of Christmas lights off one garage wall socket, then plug in the compressor in the same socket some night while on Christmas vacation.... well the breaker is going to blow.
Normal remedy is to turn off / remove the items from the circuit, then reset the breaker.
In MY opinion, the on/off funcitons of a device should be SEPERATE from current protection offered by a fuse or circuit breaker.
This is just MY opinion. Of course, if space/weight is a number one priority then other options may well be the preferred choice for the application.
Good luck,
jlfernan said:
Switch breakers are a really neat idea. I just wonder, "WHY?"
The answer may very well be, "to free up plenty of room".
In MY opinion, I do not like the idea of combining "on/off" switch function with "circuit protection".
There is a distinct difference between the two choices used everywhere else.
If you run the 30 cords of Christmas lights off one garage wall socket, then plug in the compressor in the same socket some night while on Christmas vacation.... well the breaker is going to blow.
Normal remedy is to turn off / remove the items from the circuit, then reset the breaker.
In MY opinion, the on/off funcitons of a device should be SEPERATE from current protection offered by a fuse or circuit breaker.
This is just MY opinion. Of course, if space/weight is a number one priority then other options may well be the preferred choice for the application.
Good luck,
Hail VAF Dan,
Sir, I do honestly wish you the best of luck if you do have an serious electrical problem on ONE circuit.
Your willingness to shut everything down, regardless of the flight circumstances, for one failed system ( in one failure mode ) is surprising to me. Possibly your actions would be correct in some circumstances, but I can not imagine that any current flight training program advocates shutting EVERYTHING DOWN because of ONE system failure.
And again, my comments suggested PIC CHOICES. If such a problem, as in fire/smoke amoung closely located circuits made it impossible to pull the appropriate breaker immeadiately, it would still be possible to TURN the MASTER OFF right away. Then, as/when time allows, pull the CB's likley to provide power to that area, and return the Master to the ON posistion restoring the rest of the funcitoning equipment. With a fused system, this option is not as easily available.
Fused systems are going to work the vast majority of the time without issue. If you are comfortable with how you have set up the wiring for your plane, then so am I. There is often more then one way to resolve an inflight failure with satisfactory results. The intent of my post was to state that MY opinion is that CBs give the PIC CHOICES. Anyone is welcome to dissagree with me, as that is what happens when oppinions are stated.
Thanks for the feedback, and good luck,
dan said:
Sir, I do honestly wish you the best of luck if you do have an serious electrical problem on ONE circuit.
Your willingness to shut everything down, regardless of the flight circumstances, for one failed system ( in one failure mode ) is surprising to me. Possibly your actions would be correct in some circumstances, but I can not imagine that any current flight training program advocates shutting EVERYTHING DOWN because of ONE system failure.
And again, my comments suggested PIC CHOICES. If such a problem, as in fire/smoke amoung closely located circuits made it impossible to pull the appropriate breaker immeadiately, it would still be possible to TURN the MASTER OFF right away. Then, as/when time allows, pull the CB's likley to provide power to that area, and return the Master to the ON posistion restoring the rest of the funcitoning equipment. With a fused system, this option is not as easily available.
Fused systems are going to work the vast majority of the time without issue. If you are comfortable with how you have set up the wiring for your plane, then so am I. There is often more then one way to resolve an inflight failure with satisfactory results. The intent of my post was to state that MY opinion is that CBs give the PIC CHOICES. Anyone is welcome to dissagree with me, as that is what happens when oppinions are stated.
Thanks for the feedback, and good luck,
W1Curtis:
Couldn't agree more, the worst possible place to troubleshoot smoke or flames is in the air. All off, land as soon as possible and trobleshoot on the ground.
Smoke and flames can ruin your day in a New York minute. If a CB didn't pop, then you are forced to identify the fault while flying, choking, spitting and gagging, possible while fighting a fire (you do have an extinguisher, right). Nope, it doesn't matter whether I'm flying with CB's or fuses, step 1 is to turn off the master, step 2 is to land, step 3 is to troubleshoot.
Now if I'm IMC, then I might alter this a bit as follows:
step 1 turn master off
step 2 turn off all selectable equipment
step 3 turn master on
step 4 turn flight essential items on one-at-a-time
step 4 land as soon as possible
step 5 troubleshoot
I don't see a difference here between fuses and CB's when the circuit protector fails to perform.
Jekyll
Couldn't agree more, the worst possible place to troubleshoot smoke or flames is in the air. All off, land as soon as possible and trobleshoot on the ground.
Smoke and flames can ruin your day in a New York minute. If a CB didn't pop, then you are forced to identify the fault while flying, choking, spitting and gagging, possible while fighting a fire (you do have an extinguisher, right). Nope, it doesn't matter whether I'm flying with CB's or fuses, step 1 is to turn off the master, step 2 is to land, step 3 is to troubleshoot.
Now if I'm IMC, then I might alter this a bit as follows:
step 1 turn master off
step 2 turn off all selectable equipment
step 3 turn master on
step 4 turn flight essential items on one-at-a-time
step 4 land as soon as possible
step 5 troubleshoot
I don't see a difference here between fuses and CB's when the circuit protector fails to perform.
Jekyll
Sam Buchanan
been here awhile
Yep, that original line made the siren go off on my, uh......Smoke Detector......
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gmcjetpilot
Well Known Member
philosophically speaking
You know stuff happens and you might have a bad day no matter how you wire your plane. IMC with an electical fire........ or what ever "Snakes On a Plane" scenario you want to paint, may be your last. It just will not matter fuse v. CB. You can drive your self nutty with what ifs, but I think you have more to worry about statistically in a single pilot, single engine plane than what treat you think a fuse or CB brings.
For those that have creative minds and come up with gloom and doom senerios I say this, DESIGN YOUR ELECTICAL SYSTEM BY FACTS, NOT FEAR. You can design the B747 of electical systems but still have the prop fall off. The likely hood of a CB or FUSE causing the accident is remote, especially if basic good wiring practices are followed.
Back in the DAY flying factory GA planes, the standard procedure was to turn the MASTER off if you smelled smoke. With VAC flight instruments and an engine running magnetos and mechanical fuel pump, independant of electical power, you could fly without electricity. THIS HAS NOTHING TO DO WITH FUSE OR CB'S. The issue of the increased dependence on electricity from Glass Flt Inst. panels and electrically dependant engines, with electric ignition and fuel system, is important but not a CB v Fuse issue.
I am all for the instruments with a self contained battery EFIS/Gyro like a Dynon or the Sporty's Back-up gyro, but this is not what we are talking about here.
CB's are now and have been the standard for sometime in the aircraft industry, Cessna, Piper, Cirrus, Lancair Columbia........ What does it mean? Nothing but it's a standard or common practice. My wiring is easily understood by any A&P/AI or person familiar with aircraft wiring. Using CB's readily accessible and visable on the panel, I achieve "commonality" with factory planes. Hidden and remote fuses blocks under the panel, cowl or elsewhere is a unique aeroelectric "experimental" thing. That does not mean it is better or worse, just different. Pick you poison. Some may say, so what, I have an experimental and I don't have to follow those stinking factory planes. Fair enough. Each to their own.
Common design and procedures are a plus to me. Sure it is experimental, but I use a certified engine and prop combo for a reason! I understand builders desire to improve their experimental, which they are free to do. I have no issue with fuses, but it is nothing new, no earth shaking invention or breakthrough in DC power distribution and wiring safety. There's nothing new under the sun, just a rehash of the same old.
Homebuilders wiring has improved over time, but there have been no quantum leaps. Little things like better fuses. The old glass tube fuse was not as good as today's ATC flat blade fuses, which already have been around about +20 years now. Same with CB's, they have improved over the years, but the principles of both are still pretty much the same and well understood. There are better CB's for aircraft coming down the road with fault interrupt. Probably too expensive for us or GA planes. So I see technology has brought the fuse into the picture with a small improvement. Some might argue a solid state is the ultimate wiring protection? How good do we need?
Just consider there are old planes, 30 or more years old, with realitively tired and poor electical systems, some with fuses, some with CB's, that are still flying with great reliability. How much better can we do than that? Don't over worry about it. Good grounds, solid terminal connections and safe wire runs, using quality parts is way more important than the choice of fuse or CB.
The plastic fuse block is cheaper and lighter, both good in my book. Good enough to recommend its use in an RV, but arguments that it's superior or safer is hogwash. I could make up scenarios where a pull-able CB, accessible in flight, could SAVE THE DAY, like a radio was still smoking after turning it's individual power switch OFF. We can go all day with the what if's. Still you should have a way to turn off all or most of the electical system quickly, while still staying in the air (min instrument and engine running).
I present my philosophy for entertainment purposes only, and let each individual reader decide, primarily those who have not already decided. If budget is not an issue, I would still go with CB's. If on a budget or trying to save a pound, I would have no problem with going plastic fuses block. Either way they get you into the air. Viva La Difference.
You know stuff happens and you might have a bad day no matter how you wire your plane. IMC with an electical fire........ or what ever "Snakes On a Plane" scenario you want to paint, may be your last. It just will not matter fuse v. CB. You can drive your self nutty with what ifs, but I think you have more to worry about statistically in a single pilot, single engine plane than what treat you think a fuse or CB brings.
For those that have creative minds and come up with gloom and doom senerios I say this, DESIGN YOUR ELECTICAL SYSTEM BY FACTS, NOT FEAR. You can design the B747 of electical systems but still have the prop fall off. The likely hood of a CB or FUSE causing the accident is remote, especially if basic good wiring practices are followed.
Back in the DAY flying factory GA planes, the standard procedure was to turn the MASTER off if you smelled smoke. With VAC flight instruments and an engine running magnetos and mechanical fuel pump, independant of electical power, you could fly without electricity. THIS HAS NOTHING TO DO WITH FUSE OR CB'S. The issue of the increased dependence on electricity from Glass Flt Inst. panels and electrically dependant engines, with electric ignition and fuel system, is important but not a CB v Fuse issue.
I am all for the instruments with a self contained battery EFIS/Gyro like a Dynon or the Sporty's Back-up gyro, but this is not what we are talking about here.
CB's are now and have been the standard for sometime in the aircraft industry, Cessna, Piper, Cirrus, Lancair Columbia........ What does it mean? Nothing but it's a standard or common practice. My wiring is easily understood by any A&P/AI or person familiar with aircraft wiring. Using CB's readily accessible and visable on the panel, I achieve "commonality" with factory planes. Hidden and remote fuses blocks under the panel, cowl or elsewhere is a unique aeroelectric "experimental" thing. That does not mean it is better or worse, just different. Pick you poison. Some may say, so what, I have an experimental and I don't have to follow those stinking factory planes. Fair enough. Each to their own.
Common design and procedures are a plus to me. Sure it is experimental, but I use a certified engine and prop combo for a reason! I understand builders desire to improve their experimental, which they are free to do. I have no issue with fuses, but it is nothing new, no earth shaking invention or breakthrough in DC power distribution and wiring safety. There's nothing new under the sun, just a rehash of the same old.
Homebuilders wiring has improved over time, but there have been no quantum leaps. Little things like better fuses. The old glass tube fuse was not as good as today's ATC flat blade fuses, which already have been around about +20 years now. Same with CB's, they have improved over the years, but the principles of both are still pretty much the same and well understood. There are better CB's for aircraft coming down the road with fault interrupt. Probably too expensive for us or GA planes. So I see technology has brought the fuse into the picture with a small improvement. Some might argue a solid state is the ultimate wiring protection? How good do we need?
Just consider there are old planes, 30 or more years old, with realitively tired and poor electical systems, some with fuses, some with CB's, that are still flying with great reliability. How much better can we do than that? Don't over worry about it. Good grounds, solid terminal connections and safe wire runs, using quality parts is way more important than the choice of fuse or CB.
The plastic fuse block is cheaper and lighter, both good in my book. Good enough to recommend its use in an RV, but arguments that it's superior or safer is hogwash. I could make up scenarios where a pull-able CB, accessible in flight, could SAVE THE DAY, like a radio was still smoking after turning it's individual power switch OFF. We can go all day with the what if's. Still you should have a way to turn off all or most of the electical system quickly, while still staying in the air (min instrument and engine running).
I present my philosophy for entertainment purposes only, and let each individual reader decide, primarily those who have not already decided. If budget is not an issue, I would still go with CB's. If on a budget or trying to save a pound, I would have no problem with going plastic fuses block. Either way they get you into the air.
Viva La Difference.
Last edited:
Smoke or Mirrors?
Hail VAF members!
Yea yea yea, I got a little excited, my first post and all.
Anyways, I understand some of you didn't like my sentence that sounded like "My Doubletalk Emitter was way into the yellow here!".
Take a looky here:
http://www.dra73.org/intermod101.html
"Anytime two or more RF signals are brought together in a mixer, sum and difference frequencies are produced."
And of course, I can link to a site with a more laymans approach, larger RF engery source lacking the second RF signal for intermod in the circuit:
http://hamjudo.com/notes/cdrom.html
Note: The above light show could have just happened on the traces to your GPS reciever; since it was
enclosed in it's case, you couldn't see it. (You MIGHT have seen the smoke... )
Wait, there is more!
I certainly have ZERO desire to write a 5 page article on the subjet when one silly sentence gets
the point across. Read just ONE article that mentions SOME of the issues here:
http://www.issues.org/19.2/strauss.htm
The article above referenced electronic equipment, many that are manufactured under compliance with Part 15 FCC regulations. Of course there ARE devices INTENDED to transmit ... ( NOT FCC Part 15 compliant )
YES, this means Cell Phones.
And of course, here is a link of what can happen with cell phone useage, dispite their very low
power output:
http://www.wired.com/news/culture/0,41177-0.html
An indepth read on further Cell Phone useage here:
http://www.spectrum.ieee.org/print/3069
And, if you still think I just write silly sentences, you can read about flight issues with the devices NOT intended to transmit. And, a very many of you use THESE "IN FLIGHT" for navigation.
http://gpsinformation.net/airgps/gpsrfi.htm
So, maybe I wrote a sentence that sounded "silly" and came across as "My Doubletalk Detector was way into the yellow here".
Maybe I was right. And, maybe I was just trying to help educate (without writing my own 50 page post ... er book).
Sprig
Hail VAF members!
Yea yea yea, I got a little excited, my first post and all.
Anyways, I understand some of you didn't like my sentence that sounded like "My Doubletalk Emitter was way into the yellow here!".
Take a looky here:
http://www.dra73.org/intermod101.html
"Anytime two or more RF signals are brought together in a mixer, sum and difference frequencies are produced."
And of course, I can link to a site with a more laymans approach, larger RF engery source lacking the second RF signal for intermod in the circuit:
http://hamjudo.com/notes/cdrom.html
Note: The above light show could have just happened on the traces to your GPS reciever; since it was
enclosed in it's case, you couldn't see it. (You MIGHT have seen the smoke... )
Wait, there is more!
I certainly have ZERO desire to write a 5 page article on the subjet when one silly sentence gets
the point across. Read just ONE article that mentions SOME of the issues here:
http://www.issues.org/19.2/strauss.htm
The article above referenced electronic equipment, many that are manufactured under compliance with Part 15 FCC regulations. Of course there ARE devices INTENDED to transmit ... ( NOT FCC Part 15 compliant )
YES, this means Cell Phones.
And of course, here is a link of what can happen with cell phone useage, dispite their very low
power output:
http://www.wired.com/news/culture/0,41177-0.html
An indepth read on further Cell Phone useage here:
http://www.spectrum.ieee.org/print/3069
And, if you still think I just write silly sentences, you can read about flight issues with the devices NOT intended to transmit. And, a very many of you use THESE "IN FLIGHT" for navigation.
http://gpsinformation.net/airgps/gpsrfi.htm
So, maybe I wrote a sentence that sounded "silly" and came across as "My Doubletalk Detector was way into the yellow here".
Maybe I was right. And, maybe I was just trying to help educate (without writing my own 50 page post ... er book).
Sprig
mlw450802
Well Known Member
AMEN!jcoloccia said:Mine's in the red now...
There is some valuble information we can take from here, though. If you ever build an airplane out of old CD-ROMS, don't fly it through a giant microwave oven. Words to live by...
This is the significant quote that I got from the articles:
"Airlines generally abide by the FAA's recommendation, but what they don't tell passengers is that no agency -- not even the RTCA -- has come up with definitive evidence of portable electronic devices interfering with a plane's instruments. "
-mike
