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Fuse Blocks for Experimentals

stknrddr

Registered User
Greenville (north east), Wi. U.S.A.
For experimentals, can anyone suggest:

1. a suitable fuse block/s (auto style) to use, opposed to individual Glass fuses in fuse holders, and opposed to circuit breakers?

2. thoughts on mounting location, either in the panel, or under the panel?

thanks!
john
 
Here's a couple I was looking at:

10-fuse Waterproof Fuse Block ($9.00)
and
Liteway 10-Way Fuse Block ($15.00)

Both have the LED lights that indicate which fuse is blown, and both use the [FONT=&quot]standard .250" male quick disconnect terminals. The main difference is that the first one has the terminals at the rear (which I would prefer, since I was planning on panel mounting it), the second one has them beside the fuses, angled at 45º toward the front.

They also make a zillion of these with screw-type mounts for ring terminals, if you want to go that route.[/FONT]
 
West Marine is a good source of higher grade marine type stuff, and I seem to remember them having some power panels complete.
 
Not sure they are better but for a simple experimental they have thier place, light and cheap. There is a line of reasoning that if the breaker trips (or blows) you don't really want to reset it anyway until you find the problem on the ground (Bob Nuckolls, Aeroelectric Connection) John I reccommend this book to you. I've used several from BandC with good results. The whole fuse block set up is about the same cost as one breaker and can be mounted under the panel to save panel space. I know from a certified perspective they may not make sense but in the exp world they are used quite successfully.
 
Fuses/breakers are safety items, so don't forget that. They prevent fires/loss of equipment, and possible human damage. Certified or not, that's an area where price shouldn't over ride purpose.

I don't like the automotive fuse blocks as they retain the fuses by friction fit. World wide, glass fuses are easier to find than the blade types. I use breakers, whether certified or experimental, as the styles I use are relatively sealed and have a good track record. Also be sure not to use the non resettable breakers. If one trips during a flight, you might just need to force the reset to keep a function (think fuel transfer pump with no place to land).

When I do use fuses, I favor a water resistant type (Bulgin FX0180). Simple to install on an existing wire and stays intact when installed.

Web
 
I use blade fuses. They are more reliable than the out dated round fuses. The round fuses rely on solder joints internally which I have seen too many fail for no reason.
Not sure I have a link to the inline panel mount holders I have been using for a few decades. I will look. They have a better grip on the fuse then many of the circuit board style. The blade fuses are far easier to pull with the plastic tool designed for the purpose. I hate trying to pull a smoking hot glass tube that should have blown but has not.
 
Fuses/breakers are safety items, so don't forget that. They prevent fires/loss of equipment, and possible human damage. Certified or not, that's an area where price shouldn't over ride purpose.

I don't like the automotive fuse blocks as they retain the fuses by friction fit. World wide, glass fuses are easier to find than the blade types. I use breakers, whether certified or experimental, as the styles I use are relatively sealed and have a good track record. Also be sure not to use the non resettable breakers. If one trips during a flight, you might just need to force the reset to keep a function (think fuel transfer pump with no place to land).

When I do use fuses, I favor a water resistant type (Bulgin FX0180). Simple to install on an existing wire and stays intact when installed.

Web
Ordinarily, I would not presume to disagree with Web... His expertise and advise in this forum has been invaluable to me. But in this case, I do take exception with him on one narrow point: Those "automotive fuse blocks" are used (almost exclusively) in off-road racing, dirt bikes, and offshore racing power boats, where they are subjected to more vibration and stress than they would ever encounter in a light plane. If the "friction fit" retention was a problem, it would show up in that environment far sooner than it would in light planes.

The auto (and boating) world has pretty much moved away from "glass fuses" for the vast majority of applications (other than the occasional in-line add-on circuits). I believe you could go into pretty much any auto parts store in the world and be able to find those blade-type fuses... After all, if that country has autos on the road that were built after about 2000 or so, they're almost certainly using blade-type fuses, and thus the parts places will have them in stock.

OK - having disposed of that minor disagreement... The US Army used to have a "standard operating procedure" concerning circuit breakers... If they popped in flight, you could reset them ONCE, and once only. If they popped again, resetting was prohibited until maintenance had been performed to determine the root cause of the problem. I feel the same way about fuses – if they "fried" themselves protecting the circuit, I don't want to re-connect that circuit until I understand why it happened.

And I sure don't want to be doing that troubleshooting in the air, unless (as Web correctly points out) the design of the system in question left me no other alternative in an emergency-type situation. And here's one invaluable piece of knowledge I acquired from Bob Nuckols' "AeroElectric Connection" book and online forum: Design for simplicity, but include redundancy where essential. In the case of a fuel transfer pump as a single point of failure, it might be worthwhile to have a secondary transfer pump as a backup – on a completely separate electrical circuit, of course.

The question then becomes, is the additional weight and complexity of the backup system justified by the risk of a single point of failure? Flying in Texas, Oklahoma, and Kansas, I might say that secondary fuel transfer pump was overkill, because reasonably "survivable" places to land are abundant.

On the other hand, when flying over Canyonlands National Park recently – often going 5-10 minutes at a time where there was absolutely no place to land without destroying the airplane – I was acutely aware that my RANS S-6ES has only the engine-driven fuel pump (no electric backup) and that if it should fail, I'd be in a world of hurt... My thinking on this was probably colored by the fact that two days earlier, I was flying with a friend in his Cherokee 160 when his engine sputtered and died. Turning the electric fuel pump on restored power instantly. Turns out the engine-driven fuel pump had failed. That thought was going through my mind during the flight over that beautiful, but ultimately hostile to landing aircraft terrain.

Thus, I will be adding an electric backup pump to my plane in the near future. And I'll probably use a circuit breaker on that circuit, for the reasons Web articulated in his post. (And, yes, it's nice to be flying an Experimental, where I've got the choice to alter the system to meet my needs...)
 
IMG_9411.JPG
(click picture for bigger clearer view)
Lighter than breakers. Only breaker will be for alternator output. (Too many amps for fuse block connections)


Sent from my iPhone using SuperCub.Org mobile app
 

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Tom,
Your Summit Racing link pulls up numerous master disconnect options. Which switch/solenoid are you happy with?

Thanks,

Mr. Ed
 
This is the style switch I use in the road race cars and boats I build. These are light and reliable not to mention non conductive externally.
https://www.summitracing.com/parts/pco-5575a
It is a $20 to $30 switch and I have no clue why Summit is trying for the stupid money here but I show it for reference.
There are some very low dollar versions that one should not consider using. Low dollar as in under $10 or 15 retail.
 
Where do you mount it? I'm thinking the cool side of the firewall, but that seem inconvenient. The instrument panel seems not quite right either with those fat wires.
If you are using that as a master switch it should be located as close as practical to the battery to limit the length of unprotected wire.
 
If you are using that as a master switch it should be located as close as practical to the battery to limit the length of unprotected wire.

Preferably on the battery box itself. It's there to turn off battery power to as much as possible. The cable from the positive terminal to the switch/solenoid needs to be as short as possible.

Web
 
Blue Sea from West Marine. I made a rectangular hole in the panel just little smaller than the unit so I could mount it behind the panel on standoffs. All power and ground connections are accessible by removing the velcroed surface mount GPS. Or put all your required placards on a velcroed cover. Really saves panel space without putting breakers in the wing roots.
 
Blue Sea from West Marine. I made a rectangular hole in the panel just little smaller than the unit so I could mount it behind the panel on standoffs. All power and ground connections are accessible by removing the velcroed surface mount GPS. Or put all your required placards on a velcroed cover. Really saves panel space without putting breakers in the wing roots.

Exactly what I'm using on my project
Dan
 
yhst-142618731068637_2634_144080802
This is a good one, rear terminal and very robust circuit connection on the back side. Cut a rectangle hole for the main body to fit through and secure with the four screw points. Remove the cover. I did a lot of research as this customer wants a forward facing ATC fuse set up and I'm happy with this one. Comes in 8-24 circuit. Bussmann 15711 series, about $25
 
Very nice piece of kit!
Here is what I bought from Blue Sea

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ST Blade Fuse #5025 ST Blade Fuse #5035 Dual Bus #2701

I'll be testing these goodies soon...
 

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