Author Topic: 5kW Electric Go Kart With VEC300  (Read 3725 times)

Offline Reichen.Schaller

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Re: 5kW Electric Go Kart With VEC300
« Reply #15 on: October 15, 2021, 04:21:14 AM »
Thank you for the information. I am taking the kart to a track so I will spend the day messing with the settings to see what I get. I don’t quite understand why decreasing the rom would increase the allowable amps (my experience is with vescs) but I will try it out to see what happens. When I try to increase the acceleration rpms above 800 (even by one) I get an order error saying my value is invalid.

Offline Bikemad

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Re: 5kW Electric Go Kart With VEC300
« Reply #16 on: October 15, 2021, 12:08:11 PM »
I don’t quite understand why decreasing the rpm would increase the allowable amps (my experience is with vescs) but I will try it out to see what happens.

Current draw is relative to torque, and an electric motor running with no load produces negligible torque at maximum rpm.
As the motor is loaded, the rpm will reduce and the torque (and current draw) will increase.
If your gearing is too low, it will not allow maximum current to be drawn at higher speeds, therefore it cannot deliver sufficient power to achieve maximum speed. However, if your gearing is too high, it will draw much higher current at lower speeds, causing the motor to generate excessive heat and run less efficiently.

Check out this post for a similar problem with a jetski conversion with unexpectedly low current draw.

When I try to increase the acceleration rpms above 800 (even by one) I get an order error saying my value is invalid.



The popup tooltip in the programming software clearly indicates a maximum acceptable value of 1200, Therefore I naturally assumed that the controller would accept this value, but it now sounds like the VEC300 controller is unable to accept a value greater than 800.  :(

Alan
 
« Last Edit: October 15, 2021, 12:35:02 PM by Bikemad »

Offline Reichen.Schaller

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Re: 5kW Electric Go Kart With VEC300
« Reply #17 on: October 15, 2021, 11:49:36 PM »
I'm going to the track this weekend and am going to test out different settings then. Thank you for the help! Also, the program doesn't allow me to increase the acceleration RPMs a hair above 800. This could be because of other settings but with what I have currently I can only increase it to 800.

Offline Reichen.Schaller

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Re: 5kW Electric Go Kart With VEC300
« Reply #18 on: October 16, 2021, 09:48:00 PM »
I didn’t see that there was a second page and reposted by question, sorry about that.

Offline Reichen.Schaller

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Re: 5kW Electric Go Kart With VEC300
« Reply #19 on: October 17, 2021, 02:04:49 AM »
I changed the number of pole pairs to four but hav yet to try it out. The software says I can increase it it to 1200 but I get a warning whenever I attempt to do so. It says the input is not legitimate and that “accelerations rpms 50 ¡Ü x ¡Ü 800”

Offline Reichen.Schaller

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Re: 5kW Electric Go Kart With VEC300
« Reply #20 on: October 20, 2021, 01:19:33 AM »
I have tested the kart and the top speed is great, the only problem is the acceleration. In the software when I hover over the acceleration RPMs it tells me that 1200 is the max. However, when I try to increase it to that I get the error message saying: "Input is not legitimate accelerations rpms 50 ¡Ü x ¡Ü 800" I have tried lowering the RPMs but even at 2000 I am unable to increase the amp draw at all. Do you have any idea what this error message means? Also, my gear ratio is 18 | 72. So 1/4.

Offline Bikemad

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Re: 5kW Electric Go Kart With VEC300
« Reply #21 on: October 20, 2021, 10:48:22 PM »
The error message simply means that the controller can only accept a value between 50 and 800 for the acceleration setting.

What is the maximum measured Amp draw and what is the effective diameter of the tyre?

Alan
 

Offline Reichen.Schaller

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Re: 5kW Electric Go Kart With VEC300
« Reply #22 on: October 22, 2021, 11:29:34 PM »
I’ll need to get a new amp meter but I will get the info as soon as I can. (It end of quarter for school so there are a lot of tests)