Quote:
Originally Posted by ken
I think the switch in the pot box is bad. What kind of switch do I get to replace it? Or do I just buy a new pot box?
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Here are a couple of things to check - May be a bit basic, but sometimes the simple stuff gets overlooked.
* The pot box switch probably is a DPST switch, with one common, one normally open, and one normally closed terminal. With the throttle in the off position, the terminals you want to use are the ones that are open (off). These will close (turn on) when you press the pedal, allowing the controller to turn on, and the main contactor to close. (typical setup)
If the wires are on the wrong terminals, the controller could be on when the throttle is off, and turn off when you apply throttle. If the switch is wired to the NC and NO, and not attached to the common terminal, nothing will happen.
* The switch does not connect in series with the pot leads. The pot leads go directly to the controller, and are not switched on/off.
* Some pots have dual potentiometers, or four leads coming out of the pot. One pair will be the 0-5000k, (or whatever your controller needs) and the other will be something completely different. You can verify that you are using the correct pot by simply connecting a meter to the pot wires and running the throttle from off to full throttle. If it is a 0-5000 ohm pot, it won't be exactly 5000 ohms (could range 4,500 - 7,000 at the top end) but it will be in the ballpark.
* Another item to check is the rigging of the pot compared to the switch. If the switch closes while there is some resistance on the pot (generally more than 50 ohms), the controller may not turn on. This is because some controllers have a safety system that won't allow the controller to turn on with throttle applied so the vehicle doesn't leap forward unexpectedly.
To prevent this problem, it is a good idea to setup the pot box with a bit of dead band that allows the throttle pedal to move a bit after the switch comes on, but before the pot gets into control range. If this dead band is too small, the controller may not have enough time to boot before the pot box kicks in, triggering the high pedal disable safety.
If you have a bad wire or corroded connection, the wire from pot to controller may have enough resistance by itself to make the controller not work.
* Aside from the large HV cables, many controllers work with three small wires to the controller - processor power, and two pot box wires. These usually operate at the same voltage as the HV pack.
Your controller appears to have five wires - Are these connected to the proper component/source? Putting power or grounding one of the pot box controller leads may cause problems. Since your controller has five small wires, (two of which appear to be processor + and processor -) it may have a controller processor that doesn't use the same voltage as the main pack. Are you feeding the controller processor with 48 volts, when it is only rated 18-24v? Or conversely, are you feeding it with 12 volts when it needs 48?