Just wiring up my switches and wondering if chaining the grounds together requires a larger ground than the (+) due to the total possible current going through? I suspect yes? Should I just add up the total possible and use appropriate ground size?
Just wiring up my switches and wondering if chaining the grounds together requires a larger ground than the (+) due to the total possible current going through? I suspect yes? Should I just add up the total possible and use appropriate ground size?
912 IS
Airmaster Prop
Garmin Stack
C-FKLO
I would use a ground bus, and ground to that, chaining grounds together is asking for trouble ...
At least if my understanding of what you are doing is correct. (i.e. a sequential chain)
Run a decent size main ground lead to a terminal block (maybe 12-14 awg), and then connect your
independent grounds to it. Something like this, with wire sized accordingly.
Just think hub and spokes, and the main ground wire goes to the hub.
Jeff
I have had one ground wire break off at the ground bus so far. Apparently crimped too tightly. Imagine if this sort of thing happens with a daisy chain ground.
Eddie Forward
Flying
SS7, 912iS, Garmin G3X
Don't "daisy chain" them, but I think you are possibly talking about a common buss bar or wire across a group of switches. That is fine, and the buss bar (or wire links) needs to be sized to accommodate the total potential load. However, you don't normally switch the ground circuit. The switches will be on the positive side of the circuits. Like Jeff said, if you have multiple smaller ground wires going to a "hub" or terminal strip, the "main" wire connected to that strip and ultimately connected to the negative terminal of the battery needs to be properly sized to handle the total potential load of all the circuits combined. I would recommend getting a good book, like "AeroElectric Connection", and studying it. It would be a good resource for you and it is available online as a free download.
Last edited by jrevens; 12-11-2019 at 09:40 AM.
John Evens
Arvada, CO
Kitfox SS7 N27JE
EAA Lifetime
Chap. 43 honorary Lifetime
Previous hobby I rebuilt Land Rover Defenders. Every joke ever made about Land Rovers are about leaks and electrical issues. 99% of the electrical issued were because of bad DAISY CHAIN grounds. #friendsdontletfriendsdaisychaingrounds
Dave
KitFox 6 Taildragger
912 ULS
Whirlwind Prop
Garmin G3x
All around nice guy
Yeah I have a main ground block already. I was more thinking about the bus bars I see used for switches which then go to main ground block. And doing that with wire. But sounds like I should either get a bar or run individual grounds.
912 IS
Airmaster Prop
Garmin Stack
C-FKLO
Just the start of my rewiring. No more daisy chain/ground loop mess,
Screen Shot 2019-12-11 at 3.04.59 PM.png
There is logic behind the madness. Everything labeled 1-10 will be accessories (Keyed power) , 20-29 Ignition, 30-39 Radio (Which has its own ground for all the shielding wires)
Each circuit breaker and switch is individually wired. (Still just laying things out here, and testing the dash template)
Screen Shot 2019-12-11 at 3.12.40 PM.jpg
Last edited by 4Hummer; 12-11-2019 at 01:17 PM.
I think there may by a little confusion with terminology. The bus bars used for switches don't then go to a "main ground block". A "ground block" would denote a common "block" of connection points that is connected to ground (neg.). Switches normally switch the positive (+) side of the circuit. There is nothing inherently wrong with connecting them together with wire instead of a bar.
John Evens
Arvada, CO
Kitfox SS7 N27JE
EAA Lifetime
Chap. 43 honorary Lifetime
Thanks. I just ran individual grounds.
912 IS
Airmaster Prop
Garmin Stack
C-FKLO