Last week when I went to charge the Vue the charger tripped the ground fault circuit interupt (GFCI) outlet. For those not familiar with GFCI they are the outlets you have in your bathroom and kitchen to prevent you from electrocuting yourself near water.
In simple terms the GFCI works by detecting the current in the hot leg of the circuit (going out) and the neutral leg of the circuit (returning). Under normal operation they are the same (or within a few milliamps). If for some reason there was a path for the electricity to flow other than the wires, say you standing in a puddle holding an electric appliance, the GFCI would detect this and shut off the circuit. That way the electricity wouldn't flow through you to ground.
When the charger on the Vue is working it sends electrical current through the wiring to the batteries. Under normal circumstances this circuit is isolated from the vehicle. You don't want someone touching the vehicle and creating a new path for electricity to flow through them to ground.
Unfortunately there are a couple of places where a connection between the wiring and vehicle frame can occur with normal use. One source is the batteries. As they charge they create an acid mist which covers the batteries. This coating can create a path between the batteries and the vehicle ground.
Another source is dirt/grime on the motor. Enough of it can create a path from the cables attached to the motor to vehicle ground.
So the purpose of the GFCI is safety during charging. If a ground fault is detected the outlet shuts off so no one can get a shock or worse, while the car charges.
Since my GFCI kept tripping I knew I had a ground fault somewhere. Now I had to track it down. After cleaning all of my batteries and putting additional insulation on some of the exposed metal battery racks I still was having the problem.
With the help of the Electric Vehicle Discussion List I assembled a sophisticated ground fault detection device. Basically it is an extension cord with one end cut off. One of the wires is connected to the vehicle chassis. The other serves as a test probe. The extension cord is plugged in and the "hot" end of the exposed cord is used to touch/probe suspected wires that may be causing the problem. If the GFCI trips than that circuit is causing the problem.
(Note to any readers. Please don't try this at home without appropriate precautions. I've been working on this high voltage electrical system for a year so was comfortable with the voltages and currents involved. I took multiple safety precautions including insulation/protection of all exposed wiring and wearing of insulated rubber gloves meant for high voltage work. And even though I am not an electrical engineer or electrician I stayed at a Holiday Inn the previous night :-0)
Using this method I eventually isolated the fault to a dirty motor. So after a little degreaser and scrubbing of the outside of the motor the ground fault was repaired.
Now for the clumsy part. During the mucking around required to access my high voltage wiring in the fuse box I put a little too much tension on a wire connection and....well the pictures below say it all. The top picture should be attached to the bottom one.
So prior to my efforts I had a vehicle that ran great, but I couldn't charge. Now I have a vehicle that I can charge, but can run.
Luckily for me the good people at CafeElectric who make what I broke also can repair what I broke. So off to the west coast it goes for repair, hopefully to return soon.
