Unusual electricial problem

Rocker

Only the second time I ever found this type of fault. My golf trolley stopped working on the golf course yesterday. No choice but to push it all the way back to my car in the car park. The problem was the copper wires inside the cable insulation corroded away and a short piece of "good" looking cable had to be replaced. Finding this fault took some time, fixing it was easy enough. I found a similar problem on a Honda 50 motorcycle over 40 years ago. On the Honda, the cable between the battery terminal and the inline fuse holder was corroded and open circuit as a result. An easy fix. One thing is that you can never take anything for granted when looking for a fault. A seemingly good cable can be the culprit. Good outcome in my case, the trolley got a reprieve from the bin and might give another season or two service.

boogieman

Must have had water seeping inside the insulation, can't imagine how copper wire would corrode any other way.  Where do you store the trolley? 

Rocker

I keep the trolley in my dry garage. TBH I don't know why this happened but the cable was completely corroded through. It must be a manufacturing fault or problem as the insulation was perfectly intact. Oddly the copper wired were a blue grey colour and most strands had turned to metallic dust like consistency. 

CabbageCat

The problem was your electricity wasn't clean enough. Have you thought about investing in a Barry Noggins Premium Electricity Scrubbing Filter:

crunchman

@Rocker is brave starting a thread about cables.  People are slipping though.  3 posts and nothing about Russ Andrews.  I'm sure he would sell you a replacement cable (at a price).

Danny1969

I think the problem is caused by the cable not being pure enough copper to begin with and thus you get a electrolysis effect which corrodes the cable ... as I said I think I'm not certain but I see this on mobility scooters which need extremely low resistiance paths from battery to Triac board to motor

boogieman

Did it smell burnt? If the copper has gone a different colour could be it's been overloaded.  

Rocker

The cable did not look damaged and it did not smell burnt.  In fact it looked perfect except that my voltmeter displayed zero volts and vigorous shaking did not do anything so it was apparent that something was wrong between the battery and the control box [about 40 cms].

I was thinking that the sealed motor control box was blown.  I first checked the speed control on the handle of the trolley.  It looked OK.  If the motor control box was blown, the trolley was destined for the recycling depot.  The battery, a Lithium unit, is very expensive [€250 three years ago] so it could be used in a new trolley.

As I wrote in the first post above, I only encountered this type of fault once before.  Keep it and the solution at the back of your mind, you might come across something similar in the years to come.  And you will know what to do.

spark240

Has it been squashed at some point, this happens to golf trolley cables a lot....the pvc insulation tends to return to its shape but the copper doesnt 

Rocker

Good question @spark240 but no. The cable was secured to the motor housing with 2 factory fitted cable ties. It is almost impossible to crush the cable where it was fitted.

ESBlonde

The electrolysys idea is a good one. Sometimes the crimped on connectors at the end are enough so that over time the copper will degrade and fail to conduct. Even BT made the mistake of using ali wire against copper when it seemed a cheap alternative 40 years ago, the ongoing repair costs since suggest it was a false economy.

ICBM

Danny1969 said:

I think the problem is caused by the cable not being pure enough copper to begin with and thus you get a electrolysis effect which corrodes the cable ... as I said I think I'm not certain but I see this on mobility scooters which need extremely low resistiance paths from battery to Triac board to motor

Aha! Finally a worthwhile use for giant oxygen-free-copper speaker cables .

ESBlonde said:

The electrolysys idea is a good one. Sometimes the crimped on connectors at the end are enough so that over time the copper will degrade and fail to conduct.

I see this quite a lot with the speaker connections in old amps too - it's one of the main reasons crimp connectors are less reliable than soldered joints.

Rocker

The problem was not the connectors failing, it was in the cable itself. The insulation looked fine, the wires inside the insulation were corroded and like a grey blue metallic dust

Gagaryn

Rocker said:

The problem was not the connectors failing, it was in the cable itself. The insulation looked fine, the wires inside the insulation were corroded and like a grey blue metallic dust

When people are talking about electroloysis in this context, I they mean galvanic corrosion due to ion migration. I think! They could be talking about hair removal!