Infineon controller wiring

[hagerty1]

I am doing a trike project. Battery pack 14s x 14p /Motor 1000w/Infinion 12fet controller all will be mounted in the back. Pack and controller will be in a sealed waterproof aluminum diamond plate case used as a heat sink for controller/converter. I need to run control wiring forward. My question is can I use a common ground wire for all controller functions ? Throttle/3SP/E-brake lever/cruise/reverse ? I want to just run a single ground wire to front of trike and use it as common. I am planning to use 20 Ga. wire for all control functions as these are all low current functions.
All phase/hall and main 49V power will stay rear.
I will also be running 2 16 Ga. leads forward Pos/Neg from a 48V-12V converter for running GPS/Lights/Stereo/Horn
The converter will run off the pack. I know this is a stupid question......can that converted 12V Neg. be used for controller function ground ?
I am using a combo full twist throttle/3SP/Cruise on right and a combo high/low light/momentary push button reverse.
I am trying to run as few wires forward as possible as they will need to be around 7 feet long routed through the frame. Can I consolidate/centralize any of the other leads? 5V Pos?
I will have a small junction box on the front of the trike so I don't have to remove all the plug ends from the various controls, I will slot one side to allow control wires with their standard plug ends to enter box with lid removed and be sealed when lid attached.
Thanks for any help
Jim

 

[teklektik]

My question is can I use a common ground wire for all controller functions ? Throttle/3SP/E-brake lever/cruise/reverse ? I want to just run a single ground wire to front of trike and use it as common. I am planning to use 20 Ga. wire for all control functions as these are all low current functions.
...
I am trying to run as few wires forward as possible as they will need to be around 7 feet long routed through the frame. Can I consolidate/centralize any of the other leads? 5V Pos?

The control functions (throttle/3SP/E-brake lever/cruise/reverse) are all very low current and can share the same Gnd and +5V leads. 20ga wire is a good minimum for physical handling and protection on a vehicle but is substantially more than these signals require electrically. If you can get you hands on some, you might find it a bit better to run one or two lengths of electronic multiwire cable with the appropriate number of 24/26ga wires. This also gets you a protective sheath.

I will also be running 2 16 Ga. leads forward Pos/Neg from a 48V-12V converter for running GPS/Lights/Stereo/Horn
The converter will run off the pack. I know this is a stupid question......can that converted 12V Neg. be used for controller function ground ?

DC/DC converters frequently have a common input/output ground and are not fully isolated anyway. So they actually share the same ground point back at the battery as the controller. But this isn't a schematic showing 'logically common' connections -- wire routing is everything. There are two considerations here:

• The horn (I'm assuming you're talking about a real auto horn not an electronic toy bike horn) is a massive inductor that will inject a lot of electrical noise onto your power and ground leads. I would really recommend that you run two dedicated leads for these so your GPS and other electronics are unaffected. This is a matter of 'best practices' and it's quite possible that you can get by without doing this - but it will be a matter of happenstance and rely entirely on the design of your electronic gear - not on wiring design. (Here enters anecdotal evidence from folks 'proving' that it works). So you can try it and wing it, or run a couple of extra leads and never worry about it. Give it it's own fuse and the leads should join the harness as electrically close to the converter as practicable.
• There are different schools of thought here, but I would not recommend sharing a ground with the control functions mentioned above. All of those signals except the throttle are effectively digital (ON/OFF) and frankly will work okay. However, the throttle is analog and any noise or increase in ground potential from heavy current draw (accessories) will be reflected in the apparent throttle voltage. Again, sharing the ground may work, but simply keeping the control functions separate from the service power is a good practice that only costs one small ground wire.

You did not mention a kill switch. This is highly recommended and requires two additional leads at full pack voltage. These carry less than 100ma and voltage drop is not an issue so thinner 20-24ga wire will do for these as well.

As a last thought - you might consider a Cycle Analyst V3 on the build. This gets you speed/power monitoring and other cool features but importantly drastically changes the fore and aft wiring. The CA uses a single multiwire cable to consolidate wiring (you would likely need a custom length). Throttle, ebrakes, 3-pos switch connect to the CA and get power and ground from there (autocruise is a throttle function - no switch). If you need regen, you can use a CA-adapter to recover the controller ebrake connection in the rear without using another wire - if no regen then a controller ebrake hook-up is unnecessary. The controller kill switch can tap the CA for pack voltage so only one wire need be run back for that. Temperature monitoring and PAS would require minimally one extra wire each if you wanted those features. And of course, your reverse wire would still need to be run. Whether the reduced/different wire runs, features, and cost are an advantage or not is for you to decide, but the wiring change is significant and a later retrofit is problematic for builds with through-frame wiring.