View Single Post
Old 12-11-2011, 02:12 PM   #8 (permalink)
thingstodo
Master EcoModder
 
Join Date: Sep 2010
Location: Saskatoon, canada
Posts: 1,433

ChargE (not yet running) - '92 Mazda MX6 LX
90 day: 33.89 mpg (US)

Ford Prefect - '18 Ford F150 XLT XTR
Thanks: 730
Thanked 528 Times in 423 Posts
Quote:
Originally Posted by JasonG View Post
You will need higher voltages for the motor and VFD. The motor will run much better on 240 or 480.
Agreed. I'll be using as high a voltage as I can reasonably get. 600 VDC is as low as I'd like to go. The VFD shuts itself down on overvoltage at 965 VDC.

Quote:
Originally Posted by JasonG View Post
Most wire is only rated for 600V, but going to 1000V MTW is cheaper than going to larger diameter cables. JUST BE CAREFULL !! High voltage DC doesn't play and will kill you quickly.
The wiring I'll be using is industrial, rated for 1000 VAC. And if I know me, it will be a size or two (perhaps 3) larger than it needs to be. Whatever size I can fit into the lugs and the terminals.

If I'm using DC/DC converters, the high voltage will be somewhat isolated. The DC/DC converter isolates from the input battery voltage to the higher output voltage. The terminals of the DC/DC converters over to the VFD should be the only high voltage 'bus'. Liberal use of fuses (which are not cheap, unfortunately) should limit the damage if a wrench falls where it should not. The DC/DC converters have a rated output current, which is 10 or 100 times lower than the current available at the terminals of a battery string - so I should not vaporize the wrench, or weld it to the terminals.

I have no reasonable way to limit the high voltage current that I am exposed to during a shock to under 4 mA (if memory serves) - the 'safe' limit for the human body according to my Arc Flash documentation (NFPA 70E for the USA, CSA Z462 for Canada). If anyone has suggestions, please let me know.

Quote:
Originally Posted by JasonG View Post
I look forward to this build.
Me Too! Creating a build log is a way to give myself some incentive to get off the couch and do something.

We'll see if that's successful.
  Reply With Quote