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Amp shunt

Smilin' Jack

Well Known Member
I have mounting the battery box and master and started relays and figured I had better look at the EMS 220 wiring and see i need to install the ammeter shunt.

With the P 680 battery installed and the relays installed as per Vans diagram, where and what terminals do I mount the shunt to if my desire is to use the suggested A mounting as shown on the Dynon EMS?

No a wiring expert by any means.
Thanks,
Smilin' Jack
 
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Typically the shunt would be wired between the alternator output and battery bus. This ensures the amperage reading shown on the EMS will indicate actual alternator output.

Notice my setup in the picture below. The shunt (the smaller of the two blocks on the firewall) is connected with copper to the current limiter on one side (which then goes to the alternator) and on the other side goes to the battery bus.

IMG_1277_640x480.jpg
 
Trevor
i can see the shunt but was I suppose to get current limiters
also?
Stein air has told me to use number 2 wire and it is a bear to bend in short radius .
I am using number 8 to go to my circuit panel buss which is the
Custom Design automatic breaker buss
jack
 
Jack,

It is not an absolute must, but it is a good idea to have a current limiter. It will protect the alternator from too large of current draw (by a fault mostly).

You don't need 2 AGW wire for a short run like that. I used 6 AGW. I'm only using 2 AGW in two places. 1. From the battery positive to the input of the master relay 2. From the output of the starter relay to the starter itself.
The wire through the firewall will be 6 AGW (which is slightly overkill itself. 8 would be sufficient).
 
Trevor is correct. I must have miscommununicated with you, because I'd advise the same thing as previously mentioned. No need to use something as big as AWG2 from the alternator, or as a feed to the shunt. As stated, typically they are inline from the Alt to the relay, and that is usually an AWG8 wire (or thereabouts). That said, if you put your shunt in the main battery line, then it depends on where you put it, because if it's in line with the battery and the contactors (on the way to the starter), then you still need to accomodate the larger current draw during startup - either with heavy wire or flat buss bar type material - which often times is easire to manipulate than fat wires. Hope that helps a little bit!

Cheers,
Stein
 
Thanks Trevor and Stein and others

Thanks Trevor and Stein,
I did find a 60 amp current limiter on line with B&C speciality products and also the holder at a very reasonable price. i'lluse the photo's onthe link that some one gave and wire mine similar to it.

Trevor you have a picture of your installation?
And while I am at it what kind of plane you fly for a living. As I see your a corporate pilot also.

Thanks for the information
Smilin' Jack
Paid 13 dues
CL60 and Hawker 800 XP
 
Hi Jack,

Please see this link to my construction log for pictures and a diagram showing the battery, relays, shunt, and current limiter.

I'm lucky enough to fly a Hawker 800XP and a Citation CJ for my day job :)
Which CL-600 variant are you flying? Where are you based out of? I'm out of UAO.
 
Hey Trevor,
Thanks for the update, we fly a 601-3A which for our owner has worked well.
N204Jk if you want to google it and the Hawker is N800EM.

We have been fortunate to be at PDK for 40 years flying and 20 with this company.
Jack
 
Nice paint job on that 800! You guys ought to look at the API winglets; they make all the difference in the world. I fly N248EC and N41EA.
If you are ever in the PDX area, give me a shout.
 
Ttrevor,
Yep we get a lot of comments on the Hawker...like going down in flames :)
We just gotthe Challenger repainted. We use to go into PDXall the time as the owners sister live there but she passed on.
Jack
 
Getting ready to add an EI FP-VA module to my EI UBG-16/FP-5L and while I think it would be much simpler to add the SHUNT to the ALT B+ lead, I think I would rather put it on the BATTERY B+ lead.

My question, does the SHUNT have to be hard mounted to the Firewall? If you mount it on the ALT B+ lead can it be just mounted inline with the ALT B+ Cable and cover it with HEAT SHRINK or something else in the same fashion?

Or is really the only/best option to mount it to the firewall and then run cables to/from it?

Thanks in advance!
 
I used Trevor's suggestion and mounted mine like he showed. , which I think is a great. I point out this if your shunt should it vibrate around and the heat shrink get frayed and shorts out. it is the total output of your alternator going up in smoke. This would not be a good day.
Jack
 
Get some 4 ga welding cable from your local welding supply. Can handle just as much current and heat as normal battery cable but much more flexible. Buy a decent 4 ga crimper and crimp the battery terminal ends on the welding cable (can buy them at auto supply store). Then solder them on using a torch.

Easy and much cheaper than having cables custom made. Plus you can make them exactly the length you need them.
 
Get some 4 ga welding cable from your local welding supply. Can handle just as much current and heat as normal battery cable but much more flexible. Buy a decent 4 ga crimper and crimp the battery terminal ends on the welding cable (can buy them at auto supply store). Then solder them on using a torch.

Easy and much cheaper than having cables custom made. Plus you can make them exactly the length you need them.

Did you just use the S word with wiring on a plane? just trying to stir a pot.
 
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