Zapi Schematic

1/28/96

Here is a diagram of wiring changes to my previous Schematic needed for installing the Zapi H3 controller. The extra complexity comes in as a result of adding regenerative braking to a series wound motor. Specifically the three relays between the controller and motor are "extra" parts required to perform the switching. These are the same contactors I showed photos of in step 13, BFR is the single contactor and BTA/BTI are the big dual reversing contactor.

I've also added an inertia switch to the diagram. This is a safety cutoff switch that engages during impact, shutting off the power. The light blue, central rectangle is the Zapi and I've drawn in only those connectors that are applicable to the schematic. The potbox is, of course, hooked to the car's normal gas (volts?) pedal and the extra switch below it is hooked up to the brake and signals the Zapi to start regenerative braking.

There are essentially three phases of regenerative braking and I'll try to explain each one.

• The first occurs when you let off the accelerator. The controller causes a slight amount of regeneration which gives you the same feeling as letting off of the gas in a standard transmission vehicle. The general opinion about this is not to setup the controller this way, but learn to take advantage of coasting in your driving habits.
  
• The second step of regeneration happens once you lightly step on the brake pedal. For all intents and purposes the brakes aren't really on, but the brake light has come on and the Zapi kicks in with a heavier regenerative braking and thus it feels like you've applied some brakes.
  
• Finally we step on the brakes fully. The Zapi continues to apply regenerative braking which aids the normal brakes that are also being applied. I've made this a separate step just to distinguish the difference between braking with the motor and with both the motor and the standard brakes.

In fact there's a bunch of stuff about the Zapi I'm not explaining here, most of it because I don't understand it! The Zapi H3 comes with a nice big instruction manual full of charts, graphs, and specifications. It also has nice wiring diagrams for hooking up your EV, along with another machine you might use a Zapi in: a fork lift! That's right, most of the controllers used in EVs come from companies that have made and are probably still making lots of controllers for golf carts, fork lifts, and other manufacturing equipment. Next time you go to a big warehouse store take a closer look and listen to the forklifts driving up and down the isles. Also notice that the store isn't full of exhaust fumes.
Also not shown is the connector for the optional programming console. I didn't order this and I don't think I'll have to. The console is primarily for deeper setup and troubleshooting tasks, of which I'd like to avoid for now. (sure, sure)

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