considering 4ga wire upgrade?

[TerryH]

Controllers can have significantly more motor output than battery input. The Zilla controller on the dragster is able to send 2000 amps to the motor with 900 amps input from the pack. We run 2/0 cables from the controller to the motor and 1 gauge cables every where else. Not sure how much if any difference that would make on a regular cart. I'd just put 2 gauge cables every where and call it good. That's what we did on our PDS cart.

You can see the cable difference on the dragster here...

[Sergio]

Any time the PWM is less than 100% the current from controller to motor is higher than battery pack to controller.

At 50% Armature PWM (half-throttle), the motor side will be getting 24v (assuming a 48v system).

So 100 amps at 24v would be only 50 amps on the 48v side.

The current will never be higher than the maximum the controller can deliver, and being that it only happens at less than WOT (100% PWM), the current is likely always less than the maximum that could flow through all cables.

There is no benefit in making the motor cables of a heavier gauge.

Edit: Unless of course You have one of those "slightly" modified carts like TerryH, a Zilla controller with a specialized hairball that optimizes current ramp to neck braking rates and an over-sized battery pack used as an energy buffer .

[scooterman]

I think I misunderstood the original statement, thinking he was saying more current then the controllers rating. If I remember correctly on the precedent the gauge to the motor is the same as the ones from the batteries.

[glassk]

Originally Posted by TerryH

Controllers can have significantly more motor output than battery input. The Zilla controller on the dragster is able to send 2000 amps to the motor with 900 amps input from the pack. We run 2/0 cables from the controller to the motor and 1 gauge cables every where else. Not sure how much if any difference that would make on a regular cart. I'd just put 2 gauge cables every where and call it good. That's what we did on our PDS cart.

You can see the cable difference on the dragster here...

I like that kill plug set up, Some one is well versed on the Mill it seems,...

[TerryH]

Originally Posted by scooterman

I think I misunderstood the original statement, thinking he was saying more current then the controllers rating. If I remember correctly on the precedent the gauge to the motor is the same as the ones from the batteries.

Typically the controllers stated output rating is the real limit with some exception. I know with our Alltrax DX600 on the PDS I saw it spike up over 800 amps when I was initially testing the high speed gears and D&D motor combo. The Zilla on the other hand does not do that. The rating is the absolute max it will put out.

With the current levels on a normal cart even with aftermarket controller, it is unlikely that there will be any advantage to running bigger cables from the controller to the motor. 4 gauge is probably fine. I used the 2 gauge on the PDS cart just for peace of mind that the cables were not going to be a limiting factor.

[TerryH]

Originally Posted by glassk

I like that kill plug set up, Some one is well versed on the Mill it seems,...

Thanks and yes he was but it wasn't me. NEDRA rules state that our kill buttons that shut off the contactors (one on the steering wheel and one on the cage deflector) are all that's required but I feel safer with a physical disconnect. We make for sure that the track workers know where it is and what to do just in case.

[cartattach]

TerryH, that's a nice looking setup. I like how you tastefully put everything together, and added a little flair with the diamond plating.

[glassk]

Originally Posted by TerryH

Thanks and yes he was but it wasn't me. NEDRA rules state that our kill buttons that shut off the contactors (one on the steering wheel and one on the cage deflector) are all that's required but I feel safer with a physical disconnect. We make for sure that the track workers know where it is and what to do just in case.

Keeping on subject , I did use 4 GA cable with the new T-875's and from controller to motor and used the stock 6GA motor ones for the fields, I get a solid 14 MPH and since it's my working around here cart that is fine for now,



You have mentioned the motor guys thinking outside the box, I thought of an extra set of brushes and pulsing some juice in the counter EMF circuit, quicker it builds -quicker the motor reaches full speed. Not sure if anybody is already working on or figured it won't help. Never know,...

[TerryH]

Originally Posted by glassk

Keeping on subject , I did use 4 GA cable with the new T-875's and from controller to motor and used the stock 6GA motor ones for the fields, I get a solid 14 MPH and since it's my working around here cart that is fine for now,



You have mentioned the motor guys thinking outside the box, I thought of an extra set of brushes and pulsing some juice in the counter EMF circuit, quicker it builds -quicker the motor reaches full speed. Not sure if anybody is already working on or figured it won't help. Never know,...

Don't think extra brushes are necessary at these current levels. We run custom 8 brush motors but we're asking quite a bit from our motors. We are experimenting with field weakening but it's nothing more than an experiment at this point and probably not a great idea for an every day cart even though people have done it here. We're pushing the envelope and motors are a consumable resource in our application. Thankful for a motor sponsor who doesn't care if we constantly destroy all of his hard work!!

[glassk]

Originally Posted by TerryH

Don't think extra brushes are necessary at these current levels. We run custom 8 brush motors but we're asking quite a bit from our motors. We are experimenting with field weakening but it's nothing more than an experiment at this point and probably not a great idea for an every day cart even though people have done it here. We're pushing the envelope and motors are a consumable resource in our application. Thankful for a motor sponsor who doesn't care if we constantly destroy all of his hard work!!

No more brushes in that Line, an extra set with separate power to add counter EMF voltage to the armature letting it build faster. Not sure if it could be done externally, anyway.