[ausev] Wire and fuse recommendations

[Brian Lasseter]

2008/12/26 Roy Hughes <crashlode at hotmail.com>:
> i am PLANNING to get the circuit breaker soon, i need help with the low
> voltage side of this build though.

I can help with that...


> i need to know what gauge wire to use between all the low voltage components

Well... it requires a bit of planning (or measuring) because the wire
gauge needed is a function of how much current the wire will be
carrying.  (Voltage only affects how much insulation is needed on the
wire... though most normal wires have 600V insulation.)  This table
will tell you how much current a given size of wire will hold
continuously:
http://en.wikipedia.org/wiki/American_wire_gauge#Table_of_AWG_wire_sizes

I used 8 gauge wiring for my biggest 12V wiring since my power
steering pump maxes at 50 amps, and my DC-DC converter maxes out at 45
amps.  (I also used 8 gauge to connect to the rest of the 12V system
in the car...)  For my other new 12V accessories... I used whatever
wire the chart told me.  The 7 amp of cooling fans each used a pair of
#18 wires, the LED under car lighting I used #16 wires, and have a
10amp fuse on the whole string of lights, the Xantrex battery meter
also uses #16 wires, and most of the random circuits that I did not
know what I was going to put on them, I put 20 amps fuses with #14
wire.

Sherco Auto Supply has just about everything you could want for low
voltage wiring... and real cheap too...
http://www.sherco-auto.com/electacc.htm

Besides wires and fuses... I might recommend some Weatherpack
connectors to make putting the car together and taking it apart a
little easier:  http://www.sherco-auto.com/cg.htm


> and what size fuses would be appropriate for the high voltage side.
> by the way the motor is the adc 4001 , the controller is a logisystems rated
> up to 550a and the battery pack will be 144v made of 18 8v batteries.

I used an A30QS500-4 Ferraz Shawmut fuse which is a 500 Amp 300 Volt
DC Fuse.  That would be perfect for your application, and Otmar still
sells them I think:
http://cafeelectric.com/shop/index.php?main_page=product_info&cPath=3&products_id=5


> the vehicle will use a 12v accessory battery, no dc-dc converter

That route will be heavier, less robust, and will require multiple
chargers... one for the 12V and one for the high voltage.   With my
12V 50Amp power steering pump... I needed a lot more power than any
single 12V accessory battery could provide.  You run the risk of
draining the accessory battery with the headlights or something, and
then having the car stop dead when power is cut to your contactors.


> p.s. does anyone have some contacts for batteries?
> i have priced them up here in DFW
> interstate is charging $152 per us8vgc
> continental is charging $144 per T-875
> discounts were mentioned for orders over 50!!
> is this about the norm?

I paid $102.84 for each of my 18x US8VGC batteries in Nov '07.  (The
price has undoubtedly gone up since then...)  I bought my batteries
from the Interstate Battery on Burleson Rd. in Austin, TX.  I never
could find anyone that stocked US8VGCHC batteries.

To quote Mark Farver from Dec 9th....

My first recommendation would be the Interstate Battery on Burleson
Rd.  Ask for the manager (Todd?) and tell him you are from the Austin
Area Electric Vehicle group.  He should be able to get your a little
better deal.  You must deal with the store on Burleson, the other
Interstate battery stores in town buy wholesale from the store on
Burleson.

The other person to try is Larry at Comel Golf Cart in New Braunfels.
His price in the past hasn't been better than Interstate, but he is
really eager to earn AustinEV's business.  He might be able to help,
and stocks both Trojan and Exide IIRC.


-- 
TTFN,
Brian "Lasso" Lasseter

"No Sane man will dance."   -Cicero (106-43 B.C.)