Screw Terminals


Saro Marcarian
 

That's not a suggestion.  It's not a special area in a far off airport.  It's also not a semi vulgar expression.

I'm curious about the use of Screw Terminals - the kind where the terminal block directly clamps your stripped and otherwise unterminated wire.  I've come across an interesting solution to handle power distribution / fuse protection for the instrument panel which utilizes these terminals.  Just wondering about folks' thoughts on this type of terminal in an aircraft environment.

I have a simple audio mixing circuit (http://www.fdatasystems.com/ap-60-audio-mixerthat happens to use this type of terminal for audio signals and it fared well after a couple of hundred hours - albeit in a low current, signal capacity.

The specific fuse / power block I was thinking of is https://czh-labs.com/czh-labs-din-rail-mount-ac-dc-532v-10-position-power-distribution-fuse-module-board-p0445-p0445.html.  Has LED blown fuse indicators, handles 40 amps total, up to 10 amps per circuit.

-Saro


Rick Hall
 

I have several of a similar design in my bucket. The terminals, not the completed fuse block. +300 hours, none have loosened up or failed. +5, +12, GND at my EMS module. 'quick' disconnects at the wing root for the NAV/Strobe cables. Pmag uses them too.

As to the fuse block design, it's quite elegant :) Unsure I'd want to push more than 10-15 maps total through it though. That said, you can get ATO fuses with a built in LED. A bit pricey at about $.60/fuse vs .12/unlit fuse, in bulk.

The plain terminal blocks are available from various sources, most common in a through hole configuration. Digi-Key, Mouser, and Jameco all sell them. The ones I have are flush mount (free hanging?) so need some sort of a mount. VHB tape has worked for me. I have a few in the parts bin, can bring one to RR if interested.

Rick

On 9/21/2019 2:34 PM, Saro Marcarian sarodude@... [canard-aviators] wrote:
That's not a suggestion.  It's not a special area in a far off airport.  It's also not a semi vulgar expression.

I'm curious about the use of Screw Terminals - the kind where the terminal block directly clamps your stripped and otherwise unterminated wire.  I've come across an interesting solution to handle power distribution / fuse protection for the instrument panel which utilizes these terminals.  Just wondering about folks' thoughts on this type of terminal in an aircraft environment.


aviationeyes
 

I've used plenty of these type of screw/clamping terminals, though not in devices directly attached to airframes. My impression is that they hang on to the wire quite reliably since (at least on the ones I used) the screw tends to be snug in its threaded hole. I don't know if this is standard or recommended practice, but I had the habit of lightly soldering the wire ends before insertion to  prevent wire fraying or cutting by the clamping force. At any rate, I would suggest the wire(s) or wire bundle be firmly anchored very near the screw terminals.

BTW, it does look like a nifty and good value fuse block. 40 Amps total divided by number of circuits = max Amp/circuit?  However, I do wonder how I would mount it. Planes typically don't have DIN rails. Since the fuse tops are about same height as the screw terminals, mounting on the panel would make fuse replacement awkward. (Awkward unless you use a special clip-tool that I've seen to reach into and grab the ATC fuse, but then that is one more thing to deal with.) I guess one could mount on a wall or sub-panel and then cover with an easily removable cover plate with a cutout for the fuses (and indicators). Maybe it would suffice to leave mostly exposed except for covering over the wires and screw terminals. Devil in the details...
--Jose

On Sat, Sep 21, 2019, at 11:29 PM, Rick Hall rickh@... [canard-aviators] wrote:
 

I have several of a similar design in my bucket. The terminals, not the
completed fuse block. +300 hours, none have loosened up or failed. +5,
+12, GND at my EMS module. 'quick' disconnects at the wing root for the
NAV/Strobe cables. Pmag uses them too.

As to the fuse block design, it's quite elegant :) Unsure I'd want to
push more than 10-15 maps total through it though. That said, you can
get ATO fuses with a built in LED. A bit pricey at about $.60/fuse vs
..12/unlit fuse, in bulk.

The plain terminal blocks are available from various sources, most
common in a through hole configuration. Digi-Key, Mouser, and Jameco all
sell them. The ones I have are flush mount (free hanging?) so need some
sort of a mount. VHB tape has worked for me. I have a few in the parts
bin, can bring one to RR if interested.

Rick

On 9/21/2019 2:34 PM, Saro Marcarian sarodude@...
[canard-aviators] wrote:
> That's not a suggestion.  It's not a special area in a far off
> airport.  It's also not a semi vulgar expression.
>
> I'm curious about the use of Screw Terminals - the kind where the
> terminal block directly clamps your stripped and otherwise
> unterminated wire.  I've come across an interesting solution to handle
> power distribution / fuse protection for the instrument panel which
> utilizes these terminals.  Just wondering about folks' thoughts on
> this type of terminal in an aircraft environment.
>



-- 
  
  skyeyecorp@...



 

Saro-
Personally, I have a bunch of devices (CNC) that use these quite reliably.
None in my aircraft, but I think I would not hesitate to use them.
But I purchased this crimper which makes the wire ends nicely manageable
without having to solder them.
It simultaneously and symmetrically crimp the circular sleeve at multiple depths securely.
-Christian
 
--        www.BrilliantDesignOnline.com
Solidworks Design & CNC Plasma Cutting

         -a division of-
www.AlpineWorldwide.com
       "We build ideas.."


On Sat, Sep 21, 2019 at 2:36 PM Saro Marcarian sarodude@... [canard-aviators] <canard-aviators@...> wrote:
 

That's not a suggestion.  It's not a special area in a far off airport.  It's also not a semi vulgar expression.

I'm curious about the use of Screw Terminals - the kind where the terminal block directly clamps your stripped and otherwise unterminated wire.  I've come across an interesting solution to handle power distribution / fuse protection for the instrument panel which utilizes these terminals.  Just wondering about folks' thoughts on this type of terminal in an aircraft environment.

I have a simple audio mixing circuit (http://www.fdatasystems.com/ap-60-audio-mixerthat happens to use this type of terminal for audio signals and it fared well after a couple of hundred hours - albeit in a low current, signal capacity.

The specific fuse / power block I was thinking of is https://czh-labs.com/czh-labs-din-rail-mount-ac-dc-532v-10-position-power-distribution-fuse-module-board-p0445-p0445.html.  Has LED blown fuse indicators, handles 40 amps total, up to 10 amps per circuit.

-Saro


lezdreamer
 

These screw terminals are widely used in industrial automation such as in factories.  Just look at any PLCs and/or terminal blocks.  They are very robust when you use the proper torque.

Robert Asis
Long EZ, KAWO


On Sep 22, 2019, at 2:58 PM, Christian von Delius alpineglobalprivate@... [canard-aviators] <canard-aviators@...> wrote:

  

Saro-
Personally, I have a bunch of devices (CNC) that use these quite reliably.
None in my aircraft, but I think I would not hesitate to use them.
But I purchased this crimper which makes the wire ends nicely manageable
without having to solder them.
It simultaneously and symmetrically crimp the circular sleeve at multiple depths securely.
-Christian
 
--        www.BrilliantDesignOnline.com
Solidworks Design & CNC Plasma Cutting

         -a division of-
www.AlpineWorldwide.com
       "We build ideas.."


On Sat, Sep 21, 2019 at 2:36 PM Saro Marcarian sarodude@... [canard-aviators] <canard-aviators@...> wrote:
 

That's not a suggestion.  It's not a special area in a far off airport.  It's also not a semi vulgar expression.

I'm curious about the use of Screw Terminals - the kind where the terminal block directly clamps your stripped and otherwise unterminated wire.  I've come across an interesting solution to handle power distribution / fuse protection for the instrument panel which utilizes these terminals.  Just wondering about folks' thoughts on this type of terminal in an aircraft environment.

I have a simple audio mixing circuit (http://www.fdatasystems.com/ap-60-audio-mixerthat happens to use this type of terminal for audio signals and it fared well after a couple of hundred hours - albeit in a low current, signal capacity.

The specific fuse / power block I was thinking of is https://czh-labs.com/czh-labs-din-rail-mount-ac-dc-532v-10-position-power-distribution-fuse-module-board-p0445-p0445.html.  Has LED blown fuse indicators, handles 40 amps total, up to 10 amps per circuit.

-Saro