Phase lost and Earth Leakage trips.

Since there are a few people watching this thread, I have another problem to contend with. 

I keep getting phase lost and earth leakage trips. After a few restarts, the problem usually goes away until the next day. I have double checked all connections. The motor connections were a little loose but the problem persists. Any ideas? The trip current is 3.5mA for the VFD. I am using 10mm^2 3 core+earth, unsheileded. about 4M long. The motor was mega tested when I bought it and I will borrow one to test again.

Here are my latest schematics

I hate Visio, but here they are.

VFD Connections and cab controls


Interlocks, Circuit Breaker VFD and 12V PSU



Chargers and Batteries

Ordered a diferent inductive speed sensor

Based on the advise here (Page 26 in PDF) for similar sensors, I need one that has a closer sensing distance.

They are quite complex devices that need more design than I anticipated.

Should arrive tomorrow to try on the weekend.

If this fails, I will need to make the drive flange 20 tooth rather than 40.

Tacho Works now :)

Using the tip provided by Johny directing me to http://www.kolumbus.fi/juha.niinikoski/Tacho/Tacho.htm I tried connecting the tacho to the 24v frequency output from the VFD via a 1k resistor and it works a treat!

Useful thinks I can display are:

RPM

Torque

Power

Throttle position

Tacho clues

Thanks to Johny on the AEVA forums this provides a clue. http://www.kolumbus.fi/juha.niinikoski/Tacho/Tacho.htm

Based on this I should be able to hook the tacho up to the VFD via a 1k Resistor. Will try again tomorrow.

The speedo works, no so the tacho

I got the speedo working today. It has an optocoupler to interface the frequency output from the VFD to the 12 volt active low of the speedo. See images below.

I cant for the life of me get the tacho going. From checking the wiring when I removed the ignition, there is a 1k resistor from the low (switched) side of the coil to the tacho. I have tried a high side opto and low side but no success yet. I really want the taco going so I can use it to read out RPM, torque, current, voltage or whatever parameter I choose.

The heater is a winner

I tested the heater today (after replacing the fuses in my multimeter. Why do they specify 630ma?)

Here are the stats. All reading are in Deg C

Voltage after test: 656V

Ambient temp: 28C

Fan on Low: 45C 

Fan on 2: 35C

Fan on 3: 39C

Fan on High: 32C

Minimum variance from ambient = 4C - fan on high

Maximum variance from ambient = 17C - Fan on low.

I am happy with that. After I get it the ute road legal, I will look at reverse cycle air conditioning.

The speed sensor problem is unresolved. I will probably bevel the teeth on the drive flange.

Reverse is sorted out with a little diode logic :). Speed sensor still not working.

I sorted out reverse with a little diode logic to make my forward / reverse switch work how I want it. The switch is a rotary switch with 3 positions. Forward / Neutral / Reverse.

Start is initiated by turning the key. This provides an interlock so the motor wont start if the switch is knocked accidentally.

I still have some problems with the speed sensor. It is dropping pulses at high RPM. It is a 3kHz unit but something is wrong with it. The max Hz of the sensor should be 4000RPM x 40 teeth on pickup = 2666Hz

See following oscilloscope photos.

Output at 30Hz. Nice and square with a bit of wobble.

Sensor output at 100Hz. Lots of dropped pulses.

Whats left?

In no particular order

1. Figure out why reverse doesn't work correctly
   
2. Install speed pickup for closed loop control
   
3. Fit drive shaft
   
4. Organise the tray cover from Geoff O'Toole
   
5. Permanently wire the charger mains side and relay interlock
   
6. Replace small blue emergency off switch with a slightly larger red one
   
7. Finish touch up painting and clear coat.
   
8. There is bound to be something I have missed.
   

It Lives!

After  a few busy days, the motor is finally rotating under battery power with the drive shaft (tail shaft) disconnected! Quite a milestone. It is running on variable speed open loop at the moment.

For some reason the motor wont reverse, it just pulses at about 100RPM.

Forward works perfectly.

I will add the speed pickup tomorrow. Hopefully that will sort it out!

When testing, ensure GOOD help is at hand.

Thankfully none of the safety measures were required :)

The team. Tim for his safety checks, Noel for a helping hand these last few days, my wife and of course myself in the grey shirt.