How To Build a Cheap Traction Circuit
 

This thread is for williamson...

Dear Ecomodders: This thread is to help you with your controller. You may ask any questions about wiring your car. The first thing I found, to save money, is that the following parts MAY be found for sale cheap on ebay: the current shunt, the fuse, and the contactor. If they aren't there now, keep trying over a few months, since it may take you a year to build. I bought these parts new, at a fraction of their usual cost. Part #'s in next post.

The fuse is Ferraz-Shawmut # A15QS 800 4. This is the cheapest type. You may want other than 800 amps. Pauls controller is limited to 775 amps. I think it would be embarrassing to blow a fuse. I've seen 600 amps recommended. I would buy one spare. They sell a holder. I found that I could hook 3 items together by bolting one to the next. This actually saves money, work, and power loss. The 3 items are the shunt, fuse and contactor. The fuse goes in the middle, on one terminal of the contactor, and shunt. Current shunts are universally interchangeable. They are standardized at 50 mv output. So you can buy the shunt for the current rating or your guage. I have 600 amps. You are more interested in the current in the range of 100 amps, than between 600 and 1000. That is, if you want to maximize your miles.

The second item you might get cheap on ebay is the contactor. There are expensive contactors, not by Tyco. The cheaper Tyco is LEV200 A4ANA. $79 at KTA services. The more expensive is EV200AAANA, $129. The differance is that the second has built in circuit that reduces the coil drain to .13 Amp, once the contactor closes. Also, a larger input voltage range. 9-36 volts. I don't think that part means anything to us who have a 12 volt battery on board. I got the better one for about $70.

The remaining parts are sold by many companies. The best prices I found were from Revolt-ev.com. Nice people. You can compare:2/0 cable: $2.84/ft, Orange colored traction circuit is now being standardized. heatshrink tubing, 3/4 in.,4 ft. probably the right amount for one car. $2.53/ft. Anderson SBX-350 connectors. These are hermaphroditic.(the same at both ends) If you have batteries in front and back, you need 4, If you have one pack, you need 2. $10.18 ea. Heavy Duty copper lugs: Warp-9 motor, Rev NA, needs 4 at 1/2 inch hole. ($1.89 ea)Rev N reqs 3/8 inch hole. ($1.77 ea)Check your battery terminal dia. Boots for teminals: red, $.76 Forget the idea of "black" for the "Minus" circuit. Both wires are equally DEADLY!!

you may install an electric heater core, if you don't have hot antifreeze. I only found one source: KTA services. The "problem" with this core is that the air way is 4 inches square. Your A/C might have an airway of 7 inches square. slightly restrictive of air flow. BUT, the only game in town. I asked them to find a larger one. I bought one. Nice people. $80.00 plus shipping.

You need a crimper for the lugs. More on this soon

Anderson makes a quick disconnect handle, meant to pull apart the Anderson connector, from the handle mounted next to the driver, in an emergency. This is an absolute requirement, but I'm going to use the e-brake release handle from a Lincoln Town-car, that matches the e-brake handle on my e-brake, except I'll paint it bright RED! The cable goes into the batterty compartment. TRACTION POWER IS NEVER NEVER NEVER run into the passenger compartment

I bought one of these on ebay last year and can't fault it:
4mm- 70mm HYDRAULIC CABLE CRIMPING TOOL (CRIMPER) on eBay (end time 29-Oct-10 18:20:37 BST)

Useful thread. Thanks.

Dear Jackbauer: Great idea. What was the model # and brand? Was it hand-pumped hydraulic? What did you pay?Thanks

We are told to never run the traction voltage into the passenger compartment. Here is catch22: We have a battery current sampling shunt. The two smal terminal make up to 50 mv that goes to the current meter on the dash. But these two wires are at traction voltage. Please note that traction voltage is ALWAYS isolated from the chassis. There is NO low, safe side!! So the two wires should be double insulated, and protected from any chance to touch a human.

There is no limit to the amount of safety devices you can install, up to the point you go broke. Everyone has to decide for themselves how much is enough.

Not on topic, but saving money always is: $55 for a crash sensor (inertia switch) from KTA services. But $4 from ebay. 87-92 Ford Ranger. But in a junk yard, or from the donor car, real cheap. Keep in mind to mount it so it trips with a forward crash. Test it by hitting a wall. And mount it where the driver can reach down and reset it.

I'm not actually sure of the model number but it crimps from 6mm to 70mm sq cable. I used 70mm on my car and it worked great. Its hand pumped hydraulic and from what i can tell is a chinese copy of the more expensive models i've seen. I paid well under 100usd inc delivery. As far as i know a similar one is sold by harbor freight in the states.

Dear readers: I will report on this when I find out the details from Harbor frieght. Thanks, JackBaur!

As to the Ceramic heater core at 4 in by 4 in., I decided to install 2, just for the air flow restriction. I'll mount them on a 1/16th inch thick alum plate.

A crash-sensor switch is used for safety, to turn off the power in an accident. I strongly recommend it, even tho the title of this thread is"CHEAP". KTA SERVICES sells on for $55.00 I bought one from Ebay for $4. You can get one off the donor car, or from a junk yard. Mine was a 87-92 Ford Ranger.

More cheap off topic: The vacuum pump for your power brakes: maybe $295 on line as a kit. But the pump can be bought new (it's your life) for $100. The brand is "Thomas"m vavios models. The model # ending in 22 pumps 22 inches of mercury. The Model ending in 18, pumps 18. I think ICE vacuum guages read about 15 #, so either will do. The #'s CDC 22 and 18, pump pressure AND vacuum. The model BDC22 is vacuum only. You know you only need vacuum. You also need a vacuum switch. I found one cheap on-line. It had the sealed bag, and the KTA Services P/N on it!

There is an article on safety at: www.inc.com/users/evainc.html?111

Circuit breakers are Airpax, 500 amps,, $175, at KTA services. But I must admit I don't see the need, as the fuse is called a "semiconductor" fuse. Let me tell you, that doesn't mean that we are passing 775 amps thru a semi conductor! That's SEMI! It means it was designed to protect semiconductor equipment, which can be damaged by a spike. So the fuse will blow quickly. The circuit breaker has a trip time, depending % overload. So does the fuse.

The Albright contactors: If you want to use one, they are more expensive than TYCO. But, first go to the Albright web and see how they rate it for Amps, not the rating published by the seller. The same goes for the rated voltage. I've seen 120 volt rated Albrights rated for 165 volts by a seller. Don't buy it, if you have over 120 volts.

I think this post is important: there are usually 2 types of people building electric cars: Auto mechanics, or electronic technicians. I will post a typical schematic. An auto mechanic may ask for a physical drawing of what he should build. ASK!. there are as many variations of circuits as there are cars. Ask what you want to do. An electronic technician can modify my schematic to fit his car.

The copper lugs must be crimped on the welding cable. There is a preferred cable: this is one with very many very small wires. This makes the cable more flexible, and therefore, easier to bend into a cramped space. Luckily, the cable from Revolt-evc.com, recommended above, is this type. The cheapest crimper is a "Hammer Crimper". Electromotive sells one for $35.00. EV america.com rents a real crimper. This company is run by Bob Batson, maybe the #1 guy in electric cars. I bought a hammer crmper for $18.95 on ebay. He has plenty more. The seller was "super-genious", at e-mail: mark@sunmarcinc.com

The above site has instructions you can download and print on how to use the crimper. Very clear!! I didn't publish the ebay item # because that may expire. Search.

More on crimping: Before you insert the cable into the lug, you put some corrosion prevention compound into the lug. Home depot sells Noalox. I think thier SKU is 498-101. A 4 oz tube. The connection is then covered with heat-shrink tubing. A 2-3 in piece will do. You can buy the tubing with meltable sealing glue already inside. Revolt sells the lowest cost tubing. No glue. You can coat your connection with 3M #5200, fast curing, then the tubing, then the heat.

Instead of buying a crimper or using a sub par hammer crimper ask around and you will most likely find an electrician who has a real crimper that either does a round or hex crimp, hammer crimps just put a dent in the round lug to keep them on the cable, round or hex crimper's shrink the lug creating a pressure weld between the lug and the cable, took 15 minutes to crimp 6 cables and they didn't even charge me, next time I need cables crimped I'll brig them beer.
I suggest cutting all of your cables to size, strip the insulation off the ends and fit the cable ends on how you want them to be masking tape works well to keep the from moving until you get them crimped, this will save the person who is helping you time and increase your chances of having them help you out later.

Ryland is 100% right, above. I wrote "cheap traction circuit". Ryland has given us a better way. Let's add some light to this topic: We want 100% contact area between the copper bundle and the inside surface of the lug. That's the best we can do. So to accomplish this, we should evaluate the crimp to see how it complies. This means a crimp from one end of the interior of the lug to the other end. It also means 100% contact all around the copper bundle. This first part means that a hammer crimp would have to be made from one end to the other, multiple crimps. The second part means the lug has to be closed down all around the wire bundle, with no air gap. the bundle can be squised into an irregular shape, that's not a problem. When I do my test of a hammer crimp, I'll report back. Can any one post as to if a hammer crimp CAN accomplish most of this?? Another good result of Ryland's post is to call to everyones attention what is required of a crimp. Visually. Now you know what to look for! Thank you, Ryland.

A hydraulic crimping tool that does a hex crimp, requires you to use the right die-set for your cable size. Every connection under the hood (or anywhere) where it might get splashed, requires a water-tight cover. When you install heat-shrink tubing over a connection, you can use a hair-dryer to shrink it. The seller listed about 4 postings up, also sells a hydraulic crimper at a good price, on his store site. About $56 US. You can cut the power cable with a hack-saw. There is an excellent article on safety at:www.inc.com/users/evainc.html?111.

A manual safety switch is made. This cuts the power off. The only problem is that it requires running the traction voltage into the passenger compartment. I chose to have the pull-handle in the passenger compartment, just like the old-fashioned choke cable. This cable should be a nylon rope because it does not conduct. You could put a plastic carrying handle on the end, just like in dept. store heavy packages.

Traction cables should NEVER, EVER wear thru thier insulation. Use plastic grommets (Home Depot) when going thru a bulk-head. Cover with a short lenght of vinyl hose where it might rub against something. Anchor it at every point to keep it from moving.

If you assume that Paul's low-cost controller will give up to 775 amps, and you use 2/0 cable, and you have 20 feet of cable in your car, then the voltage drop in the cable is 1 volt. This is a reasonable max. This is a loss of 775 watts. You also have losses in the contactor, the fuse, the controller, the Anderson connectors, etc.

You can ask any question about traction wiring.

I am posting this information for Clyde.

How to use a hammer style crimper:

http://www.rc9.net/crimper/

Traction Circuit Diagram:
http://farm6.static.flickr.com/5002/...9cb1a4a9_b.jpg
Traction circuit by AdamBrunette, on Flickr

-Adam

I've also find schematics here:

Schematics (final??) - DIY Electric Car Forums

OR
http://www.diyelectriccar.com/forums...ead.php?t=2372

Also it hard to find 144v and ~770A circuit breaker, fuse and shunt that will fit Paul's controller... most of them 120v and 400A ....

May be we should put some links to manufactures that make all of this and then it would be easy to look for price on the Internet...

Also #20 (permalink) on page 2 - link is not working :-(

Hey Youri! I almost emailed you a link to your own message, because I didn\'t realize it was you that posted it, and I thought you might find it helpful.

To 1-EV.com: thank you for the other schematics. My schematic is limited to only the traction power, and Paul\'s controller. Any one can contact me if they would like a schematic that fits thier car. This shows that there are as many traction circuits as cars. I drew my circuit with the auto mechanic in mind, not the elecronics expert. What we need is the best price for parts and only safe parts, that is, not using 120 volt parts at 144 volts, etc. I will try to post a new link to the safety discussion. It was written by, I believe, the greatest safety expert in EV\'s.

Lower-cost heater core source: rather than the excellent 4 by 5 inch heater core sold by KTA Services, Ace Hardware sells a small room heater with what appears to be about an 8 by 8 inch core. As mentioned earlier, the average A/C has an water heater core of about 8 by 8 inches. The ACE SKU is 6087092. The model is Pelonius # HC-0120. The cost is $28.99 or on sale for $24.99.It is rated for 120 volts, but I think it should work well on 144 volts for 2 reasons: 1: You will have more air flow with an A/C blower than the small fan. 2. The core most likely has wire with negative resistance. this means that if the core gets too hot, the power it draws is reduced, stabilizing the temperature. Regards to all

This guy buys a hybrid, doesn\'t get 50 mpg. Goes to dealer. Dealer says nothing wrong. He wants 50 like his friends. Dealer says he can get it like his friends but he must promise never to tell anyone how. He promises. The dealer says "LIE"!

The article on safety can be found at:www.ev-america.com. Then, at the bottom, click on "technical articles". There are 5, but #3 is "Safety First". Bob Batson is the best expert on EV\'s. I found an error in my posting two items up from here. The wire used in the heater core has a POSITIVE temperature co-efficient of resistance!