Burned a phase wire in two in the rain

[indianajo]

Coming home in the rain Sunday 2 phases dropped out, making the geared hub motor cog and useless.
Analyzing today, the blue 16 ga phase wire burned in two at a crimped flag terminal connection. Bike has been rained on occasionally for 3 years since I installed the terminal: probably was some corrosion involved. I should really use 14 ga wire but blue is not a color stocked by auto supplies and a 100' roll of alpha or belden is $70 at newark or digikey.
What a controller! 1000 watt scooter controller bought off ebay. Motor pulls fine with the burned wire cut off and a new insulated spade lug installed.

 

[PCeBiker]

Analyzing today, the blue 16 ga phase wire burned in two at a crimped flag terminal connection.
: probably was some corrosion involved.

When I made my own connections, I coated the connection with dielectric grease then covered it with 4:1 shrink tube with glue,..
The shrink tube is big enough to fit over the connector then shrink down to the wire size to seal it.

The dielectric grease not only seals out water and oxygen, but it also acts as a heat sink and heat conductor.

I coated the motor cable connector too,..

The grease is denser than air and absorbs way more heat, then conducts into the plug.

 

[mschwett]

When I made my own connections, I coated the connection with dielectric grease then covered it with 4:1 shrink tube with glue,..
The shrink tube is big enough to fit over the connector then shrink down to the wire size to seal it.

View attachment 177125

I coated the motor cable connector too,..

nice clean connections!

 

[PCeBiker]

nice clean connections!

Thanks.
I couldn't find the weird Julet connector for the brake cut-off switches, so I had to improvise,..

I couldn't stuff the stranded wire into the connector because it would get all bunched up, so I soldered the wires, but it was too lumpy and I couldn't get it the right diameter, so I soldered a ½" piece of solid bell telephone wire to the stranded wire to make pins that fit into the plug.
Luckily I have some telephone wire from the 60's.
It's thicker than the more recent stuff and it's pure copper.
The new stuff is made from tin.

There's no real power going through the plug but any water or oxygen can corrode the connection.

Note the grease on my fingers.

I could have just cut the connector off and soldered the wires on, but I only had about 3" of wire to work with, and if I screwed up and ran out of wire, I'd probably have to replace the entire brake lever.

I couldn't find that connector anywhere, so I figured that I wouldn't be able to buy a replacement brake switch either.

 

[mschwett]

nice!! i’m not embarrassed to say that i’ve used chunks of wire from random places for low voltage hacks of all types

the shrink is especially clean though, i feel like most of the stuff i have has a much smaller shrink ratio.

 

[il Munduato]

nice!! i’m not embarrassed to say that i’ve used chunks of wire from random places for low voltage hacks of all types

the shrink is especially clean though, i feel like most of the stuff i have has a much smaller shrink ratio.

I do the same.... I re_purpose wire all the time as long as the voltage rating is adequate and the insulation is also functional for the use.
Most common heat shrink is 2:1 but the glued stuff is often 4:1.
If you search you can find many other ratio but be ready to pay more.

 

[PCeBiker]

The only thing with the 4:1 stuff I have is that it's thick walled plus the glue, and it ends up pretty stiff, so it can stress tiny wires at the junction.
(Like how a power cord always breaks at the grommet where it goes I to the tool.)

 

[Slaphappygamer]

You may not have to replace the phase wire. If you have a bad connection, there will be lots of heat created there. Especially if that connector is not rated for the proper current. What would be the rating for those flag terminals? Could be a weak crimp or the connectors did mate together well. Both situations will generate heat.

Before my gaining much more knowledge (in the last couple of years), I tried to use some cheap barrel connectors from amazon. The the insulation around the connector was constantly getting hot and started melting. I saw it before it became a problem. Turns out those barrel connectors were rated for 15 amps. Now, I use mt60 plugs (rated for 90a max) for my phase wires. No more heat issues. For reference, I also have 16awg phase wires and I have a KT controller currently set to 22a max. I've had phase wires with bad connectors melt right there.

 

[indianajo]

Before my gaining much more knowledge (in the last couple of years), I tried to use some cheap barrel connectors from amazon. The the insulation around the connector was constantly getting hot and started melting. I saw it before it became a problem. Turns out those barrel connectors were rated for 15 amps.

I learned about cheap ****ese crimp terminals on a Ford Fairlane hot-rod 62 I bought in 1996. Guy sold it to me because spade lug female kept melting off the back of the ignition switch. He was getting terminals at the shack. Ignition circuit was pulling 25+ amps with a Mallory ignition pack, a burglar alarm and some other accessories. I replaced with T&B brand terminals, no more problem. These terminals are dorman, Taiwan, usually reliable. Note the dorman multi-type assortment is the same ****ese **** as everybody else. My hands are not as strong as they were in 1996 and the crimp tool does not get any longer. 16 ga is rated 10 or 15 amps (my NE Code book was stolen 2020) and my controller will put out 20 amps at 48 v. There are some hills I climb that I need full power to hold 10 mph. So 14 ga is what I need. I'm in luck, found a coil of 50' blue 14 ga at oreillys auto Thursday. Out goes the blue 16, which is all I could find 3 years ago.
Amazing how much more torque the motor puts out with one phase not burnt down to a couple of strands. I thought my 6 year old battery was failing.