Controller tuning on surron went wrong

[IsaacNewton123]

So yesterday i tried tuning the sabvoton controller on my 2022 surron light bee x, with very little knowledge when it comes to the mqcon tuning software, and tuning in general. Once i thought i was finally done, i reconnected the display, and twisted the throttle to see if the bike would work. While the motor made the usual high pitched noise, the back wheel wasn't moving at all, and after i held the throttle wide open for about 5 seconds, i heard a loud noise, and smoke started coming from somewhere on the bottom of my bike. I then felt the part of the phase wires that connect to the controller, and the green phase wire was scorching hot to the point where i burnt myself on it. After this i let the bike cool down and tried to do a hall test on it, where the motor made really weird crackling sounds as soon as the hall test started. Im very concerned, and i know it was pretty stupid to attempt to tune my controller without basic knowledge, but any insight on what could have happened would be much appreciated.

I was running a stock bypassed battery, a sabvoton 72200 controller and a ko rs motor. The previous owner also removed the breaker for what I'm assuming was increased performance.

I made sure the amp draw was limited to 90 amps before i saved the tune, as to not damage the battery.

 

[AGS]

Oh dear. If it was mine I would open up the motor to see what damage to the windings has occurred.

The controller will also need testing to determine what condition that is in.

Here are a couple of links for mosfet and hall tests that you can do first without opening anything up.

Mosfet test

https://ebikes.ca/documents/BlownMosfets.pdf

Motor hall sensor test

https://ebikes.ca/documents/HallSensorTestingFinal.pdf

 

[E-HP]

So the bike not running right when you bought it and needed tuning?? What were the symptoms?

5 seconds of full throttle into a stalled motor can cause major damage. You could test the resistance between phases and between phase to ground without opening the motor to get an idea about how bad it is.

 

[IsaacNewton123]

So the bike not running right when you bought it and needed tuning?? What were the symptoms?

5 seconds of full throttle into a stalled motor can cause major damage. You could test the resistance between phases and between phase to ground without opening the motor to get an idea about how bad it is.

The bike had a delay in the throttle, and i wasn't entirely sure how much current it was pulling from the bypassed battery. What parts could be damaged in the motor?

 

[IsaacNewton123]

Oh dear. If it was mine I would open up the motor to see what damage to the windings has occurred.

The controller will also need testing to determine what condition that is in.

Here are a couple of links for mosfet and hall tests that you can do first without opening anything up.

Mosfet test

https://ebikes.ca/documents/BlownMosfets.pdf

Motor hall sensor test

https://ebikes.ca/documents/HallSensorTestingFinal.pdf

Thanks for the links! I'm kind of assuming at this point that the controller is fine, as the throttle and display still work, and i can still connect to it via Bluetooth.

 

[AGS]

You can do some checks to determine the state of the phase wiring inside the motor without opening it up.

Disconnect the battery first.

If you disconnect all three phase wires from the motor to controller then slowly rotate the wheel by hand the wheel should rotate without feeling any resistance from the motor. The motor should not cog.

If you connect any two of the phase wires together then you should feel a slight resistance when rotating the wheel slowly by hand. The motor should cog slightly.

If you connect all three phase wires together then you should feel a lot of resistance when rotating the wheel slowly by hand. The motor should cog heavily.

Another test you can do is to connect a multimeter set to measure ohms between each phase wire in turn and the motor case to check if any of the phases is shorted to the motor. If you read zero ohms between any of the three phase wires and the motor case then it is likely that the phase wiring insulation is damaged.

 

[IsaacNewton123]

You can do some checks to determine the state of the phase wiring inside the motor without opening it up.

Disconnect the battery first.

If you disconnect all three phase wires from the motor to controller then slowly rotate the wheel by hand the wheel should rotate without feeling any resistance from the motor. The motor should not cog.

If you connect any two of the phase wires together then you should feel a slight resistance when rotating the wheel slowly by hand. The motor should cog slightly.

If you connect all three phase wires together then you should feel a lot of resistance when rotating the wheel slowly by hand. The motor should cog heavily.

Another test you can do is to connect a multimeter set to measure ohms between each phase wire in turn and the motor case to check if any of the phases is shorted to the motor. If you read zero ohms between any of the three phase wires and the motor case then it is likely that the phase wiring insulation is damaged.

I did the test with the phase wires and it behaved exactly as you said it would. I also connected a multimeter to each of the phase wires like you said and each of them give off roughly the same reading. Does this mean its the controller?

 

[AGS]

That looks promising as far as the motor is concerned.

When you checked the resistance of each phase wire to the motor case there should be a high resistance.

Can you remember how many ohms the meter displayed when you did the test?

If the resistance is high then you should do the hall sensor test that I linked above.

 

[IsaacNewton123]

That looks promising as far as the motor is concerned.

When you checked the resistance of each phase wire to the motor case there should be a high resistance.

Can you remember how many ohms the meter displayed when you did the test?

If the resistance is high then you should do the hall sensor test that I linked above.

Good news and bad news. My motor is fine but my controller isn't! I tested out the bike with a spare 45a controller from my friend and it worked great. Would there be any point in trying to salvage the old controller or should i just buy a new one?

 

[AGS]

It depends what’s wrong with it. If it’s just mosfets then they can be replaced if you are good enough at soldering.

Try to do the mosfet test that I linked to above and then decide what to do.

Mosfets are relatively cheap to replace, but a new Sabvoton is expensive.

Also you still need to work out what you did wrong to blow up your controller or it will happen again.

 

[IsaacNewton123]

It depends what’s wrong with it. If it’s just mosfets then they can be replaced if you are good enough at soldering.

Try to do the mosfet test that I linked to above and then decide what to do.

Mosfets are relatively cheap to replace, but a new Sabvoton is expensive.

Also you still need to work out what you did wrong to blow up your controller or it will happen again.

Alright. I think the reason the controller blew is the amount of phase current i was running through it. Controller could only handle 450 phase amps peak and i ran more than that through it

 

[dominik h]

Was this an unlocked sabvoton?
Or how did you manage to run more phase amps as the max value?

 

[IsaacNewton123]

I have no idea to be honest. I bought the bike used and the controller came with it