Waterproof your controller connectors on the cheap

Electric Motors and Controllers
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MJSfoto1956   100 W

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Waterproof your controller connectors on the cheap

Post by MJSfoto1956 » Jan 12 2019 10:53am

So I'm just now starting my eZuma upgrade build and the first thing to tackle was making my wiring more manageable. To that end, I decided to start with the controller and its spider-web of wires and (un-waterproof) connectors. The concept was simple: keep it neat and keep it cheap. So off to Lowes to pick up a basic 1" electrical conduit box and two junction box adapters. From Amazon I ordered two large Daystar universal firewall boots, which just so happen to fit perfectly to the 1" junction box adapters. And of course you'll need some heat-shrink tubing as well as self-fusing tape. The picture below should say it all. On to the next item...

M
Waterproof controller connectors on the cheap.1024.jpg
#PowerVelocity #Controller #Waterproof
Last edited by MJSfoto1956 on Jan 12 2019 1:18pm, edited 1 time in total.

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spinningmagnets   100 GW

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Re: Waterproof your controller connectors on the cheap

Post by spinningmagnets » Jan 12 2019 11:39am

Good job, it is obvious that this is much better than the stock connectors flapping in the breeze. I'd like to suggest something that I believe will be a small improvement.

Have all the wires enter the plastic junction box from one opening, and locate that opening facing downwards. A sort of "drip loop".

Even for people who would never purposefully ride their ebike in the rain, anyone can get caught in an unexpected drizzle on the way home...

Voltron   1 MW

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Re: Waterproof your controller connectors on the cheap

Post by Voltron » Jan 12 2019 12:33pm

Yup... Drip loops. I do boat electric, and it's really hard to seal several wires in a bundle. You sometimes see the box full of water that's gotten trapped in there.

MJSfoto1956   100 W

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Re: Waterproof your controller connectors on the cheap

Post by MJSfoto1956 » Jan 12 2019 12:44pm

spinningmagnets wrote:
Jan 12 2019 11:39am
Have all the wires enter the plastic junction box from one opening, and locate that opening facing downwards. A sort of "drip loop".
I was thinking of doing that and still I may. The nice thing about these inexpensive, off-the-shelf junction boxes is that they come in a variety of layouts. e.g. Left+Bottom (as shown), Right+Bottom, Left+Right, Left+Left. This should give you enough variety to fit the specific layout of your bike.

M

P.S. there is to be a tight silicon plug at the small end of each rubber firewall boot (in fact, there is one already on the current boot originating from the controller). Additionally, I will wrap the large ends of the boots where they attach to the junction box with self-fusing tape. I expect this to be nearly 100% waterproof.

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amberwolf   100 GW

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Re: Waterproof your controller connectors on the cheap

Post by amberwolf » Jan 12 2019 11:23pm

It can also help to fill all connector housings with dielectric grease. It's very messy when you have to handle them, but it'll keep the water out.

If temperatures get hot enough (like here in Phoenix in summer) sometimes that stuff will liquefy enough to "run" slowly out of the housings...but most places don't get hot enough long enough for that to happen.


If you don't have the contacts (especially the part where the insulation ends on the wire) and housings coated or filled with something, then I recommend thoroughly testing your waterproofing box, with something like a pressure washer spray, and verifying that no moisture can get in at all. Otherwise, you may find that water gets in, but can't get out, so it slowly corrodes whatever it can touch. :( Happens to "waterproof" stuff frequently.

If you can't *completely* waterproof something, make sure the very lowest point in the container has an exit for the water, even if it's only a very tiny hole, or a tube going down from it, etc.

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