Ammeter Shunt - Help me connect the dots!

I'm using the Dynon ammeter shunt and would like to place it in position A so that it measures current flow in and out of the battery. However, I'm having trouble figuring out what that means in terms of what needs to be connected to what. See Dynon manual picture:



I've labeled my system with letters at each possible junction. If I want to measure current flow in and out of the battery, by using Dynon placement "A", between what two letters should I place the shunt (labled as H and G in my picture)?



Thanks for any help you can give.

with your drawing, the shunt would need to be between C and D and your loads going to the aircraft would have to come off at D. This will show current into and out of the battery. Normal in flight amps should be low once the battery has charged up.

Orange/green wire to D and orange/purple to C. If the meter doesn't move in the direction yo want, swap the leads.

I agree with Alton.

Assuming:
-battery positive is wired to A in your picture
-main bus is wired to D

You would put the shunt between C and D to measure current in/out of the battery.

However, consider this. You can tell when your alternator has gone out to lunch when the voltage on the bus is less than 14v. In that case, it would be helpful to know the current draw of the aircraft loads (i.e. position C in Dynon's diagram) so you can intelligently manage the power remaining in the battery.

To do that just wire J to H, G to D and you're done.

Just another option for you to consider.

Load meter v Battery meter

Here is you pic with some notes: (click once or twice to enlarge)
(edit fixed boo boo)

First I would recommend a LOAD (amp) meter to determine how hard your alternator is working. The LOAD meter works during flight. It tells you how many amps your alternator is putting out. That is important. It does nothing with with the engine not running or alternator off line. (Load meter between alternator and first relay or in your case the Bussman fuse.)

The BATTERY (amp) meter (like a Cessna with center and +/- scale) only works on the ground when the engine is not running. It only tells you if the battery is being charged or is being drained. In flight after the battery charged and is just sitting there, so the LOAD meter just sits there doing nothing. Boring and no info that is useful on a daily basis. (Battery meter between battery and buss. If you have multi busses that feed in parallel or dual batteries you are not going to be able to monitor all that with one shunt.)

Some justify the battery meter because if the alternator goes they SAY they will know how much drain they have. Well hooey. A Battery (amp) meter will not tell you have long you have left. The volt meter is more critical at this point, post alternator failure. If your alternator goes off line, you shed nonessential load and land. You should know about what your drain was. It will be what your load (amp) meter said before you lost the alternator. However you should know when you get to essential items what your amps are and how long you can run on battery alone. More about that below.

A LOAD (AMP) METER IS EASIER TO INSTALL AND GIVES YOU MORE DAY IN AND OUT INFO THAN A BAT METER, IMHO.

WHAT IS MORE IMPORTANT is voltage with the alternator off line. The VOLT meter and voltage give a direct battery SOC, state of charge. For an Odyssey battery the SOC schedule is:

Approx SOC numbers (see Odyssey owner manual for chart)
12.8 volt 100%
12.6 volt 80%
12.2 volt 50%
12.0 volt 34%
11.8 volt 20%

You get down to 10 to 11 volts, things will get start to go dark. Some electronics will work well below 11 volts. Most Garmin will go down to 10 volts.

SOC is the capacity in precentage. There is no need to get into detail but in general if you keep the same CURRENT or AMPs the battery will discharge at a faster and faster rate.

If you are flying sans alternator you are not going to break out the calculator and do math to determine the time you have left. To be fair voltage is not really going to tell you much, but if its falling fast and getting into the mid low 11's you are going to run out of juice sooner than later. ALSO to be fair knowing your AMP drain with a BATTERY (AMP) METER (no alternator) IS NOT GOING TO TELL YOU HOW LONG YOU HAVE LEFT EITHER!

HOWEVER you should have a good idea of what you MIN essential current drain is. The Odyssey PC680 should last. Odyssey published drain time from fully charged 100% to 10.02 volts at 10 amps of a little over 1-hour. That voltage is real low so let's split the difference, say 11.5 volts, you should about 30 min to from 12.8 volt peak to 11.5 volts.

My MIN emergency drain, electronic ignition, electronic flt/eng instruments, mater relay, Com in receive totals 4.2 amps, practical 5.7 amp load with transponder. Any lights adds from at. All I know is I have about +30 min with 10 amps, assuming the battery is in good condition.

George,
Does the more recent picture below depict a proper installation for what you describe as a "load" meter? (This is also, I believe, Dynon version B, shown above.) If so, for ease of wiring, it would work really well with what I've already mounted and wired. (I haven't mounted the shunt yet, it's just there with double stick tape, but the current limiter is.)



Given that I've already bolted my 60amp ANL limiter to the firewall, getting the shunt between that and the battery/starter relays to provide a "battery meter" (version B) would be pretty tough, unless I want to move the ANL somewhere else and leave extra holes in my firewall. Alternatively, the method Dave suggests above (version C) would work pretty easily but that would just tell me how much power I'm using. From the voluminous debate I've already read in the archives, it seems like most people choose either version A or version B (?).

Any other thoughts? My engine from Aeroport just shipped so I'm ready to put it on as soon as I get this figured out!

Yes Sir that rocks!

Yea sure that is it. That is what I would do.

PS disregard the buss feed in my previous (fixed, ok now), your last version above is correct and awesome!

One comment, pic can't show this but that brass tie from the starter relay to the Bussman thing, looks close to the metal fire wall. I am just saying, may be put some fiberglass sleeve insulator or sump-tin? It may be a mile away I can't tell, but its a dead short of the battery to ground with NO fuse, OUCH! Of course as it welds its way though the firewall you will turn the master contactor off. (I am kidding but I just get nervous seeing exposed brass ties. I know its been down 1000's of times successfully but the way it bends on the firewall side might be a little close? May be you can flip it around and put some insulation on it. Even liquid insulation in a tube would be better than nothing.

Do this, seriously
Have some one go into the cockpit and push of the firewall in that critical location (like some one might do with their foot). Than grab the starter contactor and yank on it side to side (while your buddy pushes on the firewall in that critical location). There is this dude named Murphy and he's a jerk! Ha-ha nice work; have fun hanging the engine. Make sure the shunt is perfectly level with in 0.0001 degrees.......ha-ha kidding again.

gmcjetpilot said:

One comment, pic can't show this but that brass tie from the starter relay to the Bussman thing, looks close to the metal fire wall. I am just saying, may be put some fiberglass sleeve insulator or sump-tin? It may be a mile away I can't tell, but its a dead short of the battery to ground with NO fuse, OUCH! Of course as it welds its way though the firewall you will turn the master contactor off. (I am kidding but I just get nervous seeing exposed brass ties. I know its been down 1000's of times successfully but the way it bends on the firewall side might be a little close? May be you can flip it around and put some insulation on it. Even liquid insulation in a tube would be better than nothing.

Click to expand...

Thanks George. Actually the copper strip between the starter relay and the ANL limiter is a full 1/2"+ from the firewall. It's just the angle of the pic that makes it look close. However, I will do the firewall push test you suggest just to make sure and/or twist the copper bar 180-degrees and/or add some type of insulation.

Having said all that, one thing that has been bothering me too for a while is all the exposed copper that is per Van's plans. Obviously it's all on the hot side of the battery. Van's is careful to suggest using boots over the 2AWG battery cable terminals, but says nothing about covering the copper bar. Anyone have any suggestions about whether there is something handy that would protect/insulate those bars? I've thought about just using a piece of heatshrink over them, but don't have any other ideas (and I'm not familiar with the liquid insulation George is describing).

Thanks again for the help. As always, if anyone sees anything that looks kinda funky, let me know please!

Its a good idea to tin all the copper. It will stop any major corrosion. In the marine industry it is mandatory.

alpinelakespilot2000 said:

Anyone have any suggestions about whether there is something handy that would protect/insulate those bars?

Click to expand...

The same boots as you have used on the cable will work, as you mentioned heatshrink will work, you can use multiple layers of it.

You can get nylon tubing at the hardware store in various diameters, an inch or two costs next to nothing, pick a size that will slip over the buss bar when you flatten the tubing. You could also use the boots on this.

Good luck.

Good clearance!

alpinelakespilot2000 said:

Thanks George. Actually the copper strip between the starter relay and the ANL limiter is a full 1/2"+ from the firewall. It's just the angle of the pic that makes it look close. However, I will do the firewall push test you suggest just to make sure and/or twist the copper bar 180-degrees and/or add some type of insulation.

Having said all that, one thing that has been bothering me too for a while is all the exposed copper that is per Van's plans. Obviously it's all on the hot side of the battery. Van's is careful to suggest using boots over the 2AWG battery cable terminals, but says nothing about covering the copper bar. Anyone have any suggestions about whether there is something handy that would protect/insulate those bars? I've thought about just using a piece of heatshrink over them, but don't have any other ideas (and I'm not familiar with the liquid insulation George is describing).

Thanks again for the help. As always, if anyone sees anything that looks kinda funky, let me know please!

Click to expand...

Half inch you are fine, don't worry about testing it.

Its called liquid tape
http://www.plastidip.com/industrial_solutions/Liquid_Tape_-_Electrical_Insulation
http://www.thetapeworks.com/liquid-tape.htm
http://cableorganizer.com/insultherm-spark/#prices

Actually now I think of it, from a recent discussion Permatex® Ultra Copper® Maximum Temperature RTV Silicone stuff is awesome. It's copper in name only. I called them, just curious and its a very good insulator. If you scuffed the copper buss strap and coat / encapsulate it, the dark red goop, it will look nice and not so unfinished. Permatex is avaiable at any car place, the liquid tape I don't know where they have it.

Dropping a wrench or screw driver on the buss feed bars it might cause 4th of July. Can you imagine if it jams between the firewall and strap! I could also put my wild scenario hat on; say in a crash metal crumples, subjecting the buss straps to grounding? Pretty far fetched.


Another idea is a sleeve made with fiberglass or other material. If you Google "wire braided sleeving" you will find all kinds of vendors from wrap for the brass straps. Many places sell by the foot.
http://www.techflex.com/prod_SPB.asp
http://cableorganizer.com/insultherm-spark/
http://cableorganizer.com/wire-management/
http://www.aircraftspruce.com/catalog/elpages/expandablesleeving.php


Yes, I always wondered about Van's set up. However open copper buss bars have been used for a century, in all manner of power distribution systems. As long as nothing grounds, you're cool. However I think covering those open buss bars might be a good idea and give it a finished look?


[COLOR=[B]"Blue"]Norman CYYJ[/B] - "Its a good idea to tin all the copper. It will stop any major corrosion. In the marine industry it is mandatory."[/COLOR] This would be overkill but you can buy these fiberglass sleeves of all diameters, colors and weaves to protect electrical stuff or items from heat.
Good idea!

hook the shunt to the anl limiter, than ... mark the shunt for high and low on each end. Then hook the low side to the limiter, then hook the altenator and the load for the aircraft to the High side. Then hook the high from the dynon to the high side of the shunt on the little screws, then hook the low from the dynon to the little screw on the shunt. This hook up will give you the first choice of possitive and negetive 60amps on the dynon.

Why Bat meters are no longer important

allbee said:

hook the shunt to the anl limiter, than ... mark the shunt for high and low on each end. Then hook the low side to the limiter, then hook the altenator and the load for the aircraft to the High side. Then hook the high from the dynon to the high side of the shunt on the little screws, then hook the low from the dynon to the little screw on the shunt. This hook up will give you the first choice of possitive and negetive 60amps on the dynon.

Click to expand...

"mark the shunt for high and low on each end".

The shunt is not directional or polarized. There is a voltage drop across it so I guess there is a low and high side, if that is what you mean. So you are right the high side is next to the ANL and low the other end.

"Then hook the high from the dynon......."

The shunt works on different voltage due to a slight drop across it (like milliamps).

"....will give you the first choice of positive and negative 60amps on the dynon."

You hook both shunt wires to the AMP gauge or Dynon. If it reads backwards (pos v neg) you switch the leads. Not sure what choice of pos and neg 60 amps on dynon. If you are wiring for a "LOAD METER" it should be positive by convention, but yes you could have it read negative. The EIS4000 does not do negative so it's always positve. The EIS4000 also uses a hall effect device not a shunt. The advantage with the hall effect is the wire just runs through a loop, there is not direct connection.

There are really only two ways to connect the shunt:


WARNING TECHNICAL CONTENT & HISTORY LESSON - WHY BAT METERS ARE OBSOLETE

Why BATTERY METERS are not important any more:
This is a throw back to the 1940's. Keep in mind in the old days Generators could not always provide enough charge, so it was normal for the battery to fill in and charge and discharge all the time. They really did not car what the VALUE of the current was (AMPS) but was it charging or discharging. Most Bat (amp) meters did not even have a scale. Some charge/discharge BAT gauges had just have 3-tick marks, center/zero and two full scale charge/discharge ticks, sometimes labeled, sometimes not.

Now with Alternators, that can supply 100% of the load all the time, even at idle, there is no discharge of the battery, ever when the alternator is on-line. BAT METERS have lost their charm or usefulness. In a car or plane BAT-METER'S will do nothing for you, but sit at Zero or just to the Pos side, all day long.

Many early planes including Cessna's had generators. Planes made before the 60's definitely had generators. I had a 1958 Piper twin. It had two 160 HP lycs with generators. It was common to start one engine and run RPM up to get it at least zero or just on the positive side of the BAT METER. After starting #2, you bring the engine back to normal idle. With some electrical items on, and both engines at idle, it was normal to see a slight discharge, more at night with lights on. So if you where stopped, you might bring one or both engines up a little to KEEP IT ZERO or slightly POS. You did not care what the AMPS where. You just wanted to keep the BAT out of drain mode as much as possible, however that was not always the case.

The above Generator monkey motions are not needed with an Alternator. With an alternator a Bat-meter may jump occasionally, when you put on a big electrical load, for a fraction of a second, IF YOU HAVE AN ANALOG meter/needle. With a digital display however, I doubt you will see it. It happens so fast it will not be visible. Who cares? The jump is just a nanosecond delay in the voltage regulator to keep up. Today solid state switching regulators can keep up. In the old days voltage regulators where mechanical. They had actual relays opening and closing to keep the voltage at the desired level. There where big voltage drops or brown outs when high current items came on. This is not the case with alternators and solid state regulation. You might see a wiggle of the needle but not much on a digital display.

There is no right or wrong, its like primers and tip/slide canopies, Personal preference. But if you have an alternator 100% of you power comes from it 100% of the time. It is more useful to see how much you total load is than look at a gauge that reads ZERO all day. Cheers

you mark the shunt so you know what side to hook up the wires. I marked and hooked up just as I said and works perfect.

let me add just a little here. make your wiring simple. First Dynon has you hook the amps, orange w/green wire(high) to one side of the shunt, so make that side the high, if you want mark it no.1, but I think high is easier. than you do the same with orange w/purple wire it's the low. so if you mark one side of the shunt with High and the other with Low, than you can hook up things and keep them straight, at least for me. Low side goes to the battery, the high side goes to the load and the alt. simple and staight forward.

why did I hook things up this way, simple, I want to know when there is a draw. I thought it was pretty cool to set the ems to monitor the amps while I hooked up my seat warmers, found out real quick if they were working without having to touch the warmers, negative amps when I put on the switch, pretty cool. Oh, and I did have trouble with one seat, the wiring in the loom was hooked up wrong. I like to see that my charging system is working. hooked up the way I did will show me right off.

I didn't see it mentioned in this thread but it is a good idea and Dynon recomends you use inline 1 Amp fuses when connecting the current sense wires to the shunt. Although the Dynon EMS typically will not draw any current through these wires, if either of these wires are accidently shorted to ground, you have the potential of drawing a lot of current through them until they vaporize. I used 1 Amp pigtail fuses Digikey part number F2313-ND $.55 ea. I soldered them inline and covered with shrink tubing close to the shunt. I think Dynon also says you can use a short higher gauge wire seqment instead of the fuse if you want. Either way, the idea is to keep the heat, smoke and possible sparks close to the shunt and preferably outside the cabin if either of these current sense wires short to ground.

yes indeed. I used fusable links.

FYI - Van's drawing OP-10 shows the shunt installed in cable P1 between the master relay and main bus, i.e. Position A on the Dynon diagram.

I installed the shunt in the P1 cable per the Van's drawing and mounted it vertically on the sub-panel and to the right of the LH Panel Bracket just behind a Van's Ammeter so it measures current flow in and out of the battery. I also have a low voltage indicator connected to the 60A alternator breaker.

Jim Sharkey
RV6 - Wiring etc

the thing that is cool with the d180 is the fact that you can set up the alarms for the amps in negative. What happens on my panel, the yellow light turns on when there is a warning from the EMS. So if the amps go negative, on goes the light and then all I have to do is switch the screen to monitor the EMS. Believe me the amps goes down a lot faster than the voltage. I get a warning right away, or will. So I like the +60, -60 amp reading, when the charging system quits, I'll know it.

Unbelievable...

"Believe me the amps goes down a lot faster than the voltage."

Umm, my considered opinion is that the amps and volts go down simultaneously. When the alternator stops alternating, the battery bus will drop from mid 14s, to 13 and change, instantly.

I'm with albee on this one. Sorry, George

The load-meter configuration is great if you are managing a marginal (generator) system, or developing / troubleshooting a system.

Once properly implemented, the alternator is intended to carry the entire running load of the electrical system, yes? Yes! So having the zero-centered approach is a better indication.

Zero is an easy number to memorize and see on the ammeter (thinking '62 Chevy truck here). I especially like the 'turn it RED' on a negative amp indication.

Any deviation from Z indicates some thinking:

Positive Amps: If you just started up, normal. If its (+) too long, the battery is not taking a charge i.e. a portion of the alternator output is continuously going into the battery and its not responding..

Zero Amps: the alternator is handling the entire electrical load, including keeping the battery charged. GREAT!

Negative Amps: You are taking capacity out of the battery. There can be several causes but they all add up to one thing: the alternator is not carrying the electrical load of the airplane, the battery is chipping in and your electrics will die when the battery is depleted.

I personally find this a lot easier to think about than the loadmeter approach. I don't care what the load is. I just want to know if the alternator is carrying it (fly on) or if the battery is being used to drive it (land).

So my shunt is in the battery (+) lead from the alternator (not including the starter). The (+) sense input to your ammeter should be towards the alternator but don't worry.. If the ammeter shows a (+) reading with the engine off, just swap the sense wires.


JMHO

"Zero Amps: the alternator is handling the entire electrical load, including keeping the battery charged."

Yes, but... the drawback to this approach, at least with analog meters, is that poorly performing alternators are hard to detect. If the normal indication is +1amp, on a 0 - 60amp scale, that's barely off the center mark. If the alternator is starting to screw up, -1amp is equally hard to detect.

Of course, with a high res. digital meter (efis), it's not a problem.

lucky333 said:

I personally find this a lot easier to think about than the loadmeter approach. I don't care what the load is. I just want to know if the alternator is carrying it (fly on) or if the battery is being used to drive it (land).

Click to expand...

That's exactly the way I think about it. I also have the volt meter and low voltage warning light to monitor the health of the alternator.

In the end, it's personal choice as explained several times earlier.

L.Adamson

I was playing with my Dynon with the amps. I watched both the amps and the voltage, turned the heaters for the seats on and wow, the amps dropped right off real quick into the negative, the voltage, slowely dropped a couple tenth of a volt. My money is on the amps picking up a negative discharge, or a charging system failure. Now this is with only the main switch on and no alternator working.

I agree, Ted.. and albee and L.A

... and I was going to say as well that I would set up the 'RED' discharge indication with a bit of dead band to swamp inaccuracies in the ammeter and avoid bogus readings. Say.. RED at -1/2 amp. If the ammeter is dead on and you really are that close, you'll see a dropping voltage eventually.. but we are splitting hairs.

Your assertion about inaccurate analog ammeters is valid but I'll still stick with what I said for several reasons:

1) A load meter requires you to know whether the load presented agrees with whatever stuff you have turned on. That's a lot of data points compared to just left or right of zero.

2) Once you get used to a visual position of zero, or a half-needles width one way or another, its easy to see deviation from normal.

3) In most cases (once the electrical system is properly designed and implemented) the usual failures e.g. alternator, will be easy to detect i.e. zero output reading on the loadmeter or negative reading on MY ammeter as well as whatever idiot lights come alive. My preference for the +/- amps approach is that it gives some guidance about load shedding (go for min - amps) rather than just indicating that the alternator is dead (I already know that..).

Personal preference and as albee and L. Adamson chipped in while I was writing.. Yeah. The battery voltage will drop a bit when the alternator fails but then keep the busses up at some good voltage because.. that's what its for. Better to know that your charging system is not up to snuff before the voltage drops too far to be useful.

Believable

allbee said:

Believe me the amps goes down a lot faster than the voltage.

Click to expand...

Ted is right. With the alternator running, volts are = 14.x volt. With alternator off, battery volt are 12.8-12.6 volt, if battery is fully charged. Yes you load the battery with with more amps the volts will drop slightly. (However as volts drop, a using device that needs constant power, means current goes up, ohms law.)

My point about battery voltage is that is LIFE, if that is all you have, aka alternator goes TU. The voltage is its strength. Example, you have a bunch of batteries in a drawer at home for a flashlight. You pull them out and put a VOM meter on them. The ones with more volts make you happier, they have more power avaiable.

lucky333 said:

Zero is an easy number to memorize and see on the ammeter (thinking '62 Chevy truck here). I especially like the 'turn it RED' on a negative amp indication.

Positive Amps: If you just started up, normal. If its (+) too long, the battery is not taking a charge i.e. a portion of the alternator output is continuously going into the battery and its not responding..

Zero Amps: the alternator is handling the entire electrical load, including keeping the battery charged. GREAT!

Negative Amps: You are taking capacity out of the battery.

I personally find this a lot easier to think about than the load meter approach. I don't care what the load is. I just want to know if the alternator is carrying it (fly on) or if the battery is being used to drive it (land). JMHO

Click to expand...

That is a good point, a '62 Chevy truck has a BAT METER, so it must be good. When you Chevy truck flies I'll take out the load meter and put in a battery amp meter, ha ha.

A lot of people grew up on the "How Goes It" Bat meter, straight up zero is good. On the other hand a LOAD meter takes some interpretation, but if it's reading zero, it is not Rocket Science to kow that's bad as well. So one zero is good and the other zero is bad.

The consumer (car) did not need an amp load or whould even know what to do with 23.3 amps. That is why many BAT amp meters did not have a scale. But that makes my point, they are easy for someone to read, but might give a little less info in normal operation. It's like a GO / NO-GO gauge.

Also after alternators came in use, mechanical voltage regulators where used for a time. They where notorious for failing low or high. So a ZERO is "All-Right" meter was cool, but than the car makers discovered people did not look at the gauge any way; So than they took the gauge out and put in a LOW VOLT / NO CHARGE idiot light we have had in car's since the 70's. Not may new cars have an amp meter of any type. Electrical systems are just very reliable compared to the 60's.

As someone above said, it's a GOOD IDEA (must) to have a LOW VOLT light. I agree. Regardless of the AMP meter type, BAT or LOAD, if you don't look at it, it's useless.

You make a good point, a hows goes it gauge has use. I made it sound useless but that is of course not true. There is preference. It's nice to know if the alternator/generator keeping up with the needle center or slightly on the Pos side. However a LOAD meter reading ZERO says something else, the battery is taking the load. Along with a volt meter you also have a how goes it.

Either way voltage will drop to 12.6 volts approximately and the LOW VOLT LIGHT you should have goes on.

allbee said:

I was playing with my Dynon with the amps. I watched both the amps and the voltage, turned the heaters for the seats on and wow, the amps dropped right off real quick into the negative, the voltage, slowely dropped a couple tenth of a volt. My money is on the amps picking up a negative discharge, or a charging system failure. Now this is with only the main switch on and no alternator working.

Click to expand...

Another good point. A Bat-meter is handy on the ground to check electrical load of individual items like the pitot. However you can always turn it on and go see if its getting warm or powered.

However in flight if you want to see if your pitot or landing light is working (with the alternator running) the LOAD METER is the only thing that will tell you. The BAT METER will sit there fat happy and dumb at ZERO.

gmcjetpilot said:

TAs someone above said, it's a GOOD IDEA (must) to have a LOW VOLT light. I agree. Regardless of the AMP meter type, BAT or LOAD, if you don't look at it, it's useless.

Click to expand...

I installed the low voltage light from Van's. It flashes bright red for 30 seconds at low voltage, and then goes to solid red. Should be enough to be noticed!

L.Adamson

Steve, I entered this fray a little late but to answer your question about protecting the copper bar, I used heatshrink (buy the assortment kit from Harbor Freight).

Protective flap

smithhb said:

Steve, I entered this fray a little late but to answer your question about protecting the copper bar, I used heatshrink (buy the assortment kit from Harbor Freight).
......

Click to expand...

Bret... you still have the terminals exposed...

My thought, not yet implemented, is to fabricate a flap of baffle material, and use it to loosely cover all of the power terminals in the area, possibly with a velcro attachment.

gil A

smithhb said:

Steve, I entered this fray a little late but to answer your question about protecting the copper bar, I used heatshrink (buy the assortment kit from Harbor Freight).

Click to expand...

Thanks Bret-
I was just at NAPA and found a spray can version of the plasti-dip stuff. The can says it's good for insulating, so I think I'll give that a try

az_gila said:

Bret... you still have the terminals exposed...

My thought, not yet implemented, is to fabricate a flap of baffle material, and use it to loosely cover all of the power terminals in the area, possibly with a velcro attachment.

Click to expand...

Or, just spray a dot of the above over the terminals. It would be easy enough to peel it off if the terminals needed future service. (?)

Several spots....

alpinelakespilot2000 said:

Thanks Bret-
I was just at NAPA and found a spray can version of the plasti-dip stuff. The can says it's good for insulating, so I think I'll give that a try

Or, just spray a dot of the above over the terminals. It would be easy enough to peel it off if the terminals needed future service. (?)

Click to expand...

Should work.... but you would need several layers to get a reasonable thickness.

Since there are at least 5 terminals to protect, this might be more work....

gil A

Geez Gil,

I'm building as fast as I can... The terminals will be covered before first engine start I assure you.

Steve, I don't know anything about the plasti-dip stuff but I bet it makes a real mess.

OK...

smithhb said:

Geez Gil,

I'm building as fast as I can... The terminals will be covered before first engine start I assure you.

Steve, I don't know anything about the plasti-dip stuff but I bet it makes a real mess.

Click to expand...

Bret... I was trying to save you work....

The other stuff all needs protecting, so I was thinking a a single, one piece solution instead of multiple separate ones... ...the big rubber booties are a pain to get on...

gil A

One big cover

The heat shrink is great, why did I not think of it. But how about a cover over the whole mess of relays/contactors/solenoids, shunts, ANL fuses........

Cover it all...

gmcjetpilot said:

The heat shrink is great, why did I not think of it. But how about a cover over the whole mess of relays/contactors/solenoids, shunts, ANL fuses........

Click to expand...

Yep.....

http://www.vansairforce.com/community/showpost.php?p=208559&postcount=29

gil A

Dang beat me to the punch again

az_gila said:

Yep.....

http://www.vansairforce.com/community/showpost.php?p=208559&postcount=29

gil A

Click to expand...

Gil BUDDY you have to stop showing be up and being smarter (not that hard to do) but really.......... ha ha ha great minds think alike?

Two related questions

First, what is an ANL? (and where to get one if necessary)
Second, is it necessary to have a shunt the same amps as the alternator? I have a 60A Plane Power alternator and got a 40A shunt. My reading is that perhaps the 40A shunt will just go off scale if it is charging or discharging more than the 40A. (this is all hooked to a Dynon D120)

thanks,
greg

They look like this..

http://www.vteworld.com/content/electromech/fuse/html/anl/anlfuse.php

'ANL' is a fuse type like 3AG etc.. Specifically, its a series of low voltage (32v) used in high power delivery systems (battery chargers, electric forklifts etc). The 'L' means current limited but don't get all rosy about that. It just means that the fuse is designed (by structure mainly) to 'limit' the overload current while its blowing. By 'limit' in this context, we are not talking about 210 amps. When you consider that a 200A ANL may be connected to a battery that can deliver 10,000+ short-circuit amps, limiting to 2x or 4x or even 10x this amount in the sub-seconds it takes it to blow is an advantage. Eliminates ad-hoc arc-welding you see.. Its more to stop fires from starting than to salvage your errant alternator etc..

Mainly, the ANL package useful for us because it is flat, rugged and bolts down securely. Good enough. Remember that fuses are NOT power management devices. They are present to protect wiring (the basic story) and at the 200A level, to keep you from bursting into flames when you have a serious electrical fault. Credit to Gary Newstead for that last one. I never got the whole fuse in the main line thing until he brought up the advantage of cutting off batteries when your cables get severed in a mishap or worse, especially with rear mounted batteries.. I like the idea so.. mine has ANL's too.

BTW. I have no real knowledge about the outfit in the link. Nice picture though.

BTW-II: if you want to insulate the bus strips, a thick heat shrink may be better than a coating. The plasti-dip that you can coat and recoat may build up enough to protect but a thick heat shrink is tougher. YMMV

Shunt wiring

Just finished changing some details on the firewall of the 7-A I'm building and really liked the way this picture looked.

Great job..think I'll copy you
Thanks
Smilin jack