Speed Issue On New Build

[AC9999]

I also notice the hub wheel will not spin freely while connected to the controller. Battery not connected. I can feel the magnetic resistance trying to spin it. When I unplug the connector from the motor to the controller it will spin without resistance.

 

[amberwolf]

when it's ok without controller connected then motor is ok, but with controller connected has resistance then FETs are blown.

Might be just one, might be several. Usually will all be on one phase.

Could be from original problem, or could be from mods.

Unlikely to be shunt mod as I dont' see any real amount of solder on the shunts, and moving htem closer or farther away from each other makes no difference to their resistance.

Withotu knowing what the current reading was after vs before you can't know if there was any change that coudl've caused a failure. If no change in accel or speed probably no change in current either.


Since it happened after some time of riding, best guess is heat, if the FETs were not fully and flatly clamped back to the controller case to shed their heat.

 

[AC9999]

Well good to know it's not my motor for sure. I'm thinking the mod did increase the amps a bit but the underlying problem still existed so I couldn't tell. No increase due to whatever was damaged to begin with. The increase in heat then burnt up some fets? Sounds logical. But if my mods didn't solve initial issue what else could cause a block in using the rated and available amps? If it could be a simple cheap fix then I would try that and repair the fets which are cheap enough. How do I test the fets? I have to wait till Monday to see about getting a replacement from china anyway and I doubt they'll want this one back so I might as well keep trying to repair until my replacement gets here. It might be a very decent controller once I repair or replace everything. Or at least it'll be a good backup.

 

[AC9999]

Could something as simple as a single blown FET be the issue in the first place? Could that cause a 50% reduction in speed and acceleration? Then the addition ones blew due to the mods.

Of note, currently when I spin the wheel, theres drag but its jittery. Throttle was taped to half throttle.
What is that an indication of?
Maybe a blown FET?....

Any suggestions for replacements? Maybe from here http://www.mouser.com/Semiconductors/Discrete-Semiconductors/Transistors/MOSFET I don't need the 4110's but If I can get better than the current 80NF70 specs say 68V and 98A for a decent price not from China makes sense to upgrade a bit at least. Something in between. I know I'd also have to upgrade the 63V caps if I want more battery in the future. I'll order something tomorrow. Don't want to wait if this is actually going to fix all my issues.

I still need some help on my battery dilemma. Any insight on the type of cell I asked about?

 

[AC9999]

Would this be a good replacement to go with between the current STP80NF70 68v 98A http://www.mouser.com/Search/ProductDetail.aspx?R=STP80NF70virtualkey51120000virtualkey511-STP80NF70 I have in there now that is blown and needs replacing and getting the 4110's?

IRFB7734PBF 75V 183A
http://www.mouser.com/Search/ProductDetail.aspx?qs=m1T3c8F5IULLCOSNJ%252bE3yw%3d%3d I did a search here on ES but no mention yet. Mouser says they're new.

Like I said earlier I really don't need the 4110's. I'm not pushing the system any yet and I'm not 100% sure this is going to fix the beginning issue yet either so why spend so much on them when a little upgrade is all that's needed if I'm going through replacing the FETs anyway to try and repair the controller. I'm not even sure how I'd reset the LVC on this thing in the future if I did go with a bigger battery eventually. Doesn't really matter now. I just want to fix this thing.

Might as well order some caps too while I have to ship something. Any suggestions on their available caps? I assume 100v 470uf. Any other detail spec I should look for or avoid?

 

[skeetab5780]

Just buy a real controller from somewhere. It will be quicker and easier to solve the problem. Lipstick on a pig doesn't help anyone

 

[AC9999]

Just buy a real controller from somewhere. It will be quicker and easier to solve the problem. Lipstick on a pig doesn't help anyone

I have a new one coming. Doesn't mean I can't work on this one too. Why does it bother you so damn much that I want to still work on it? You obviously don't want to really help in the repair so go bother someone else with your brilliant insight.

 

[d8veh]

It's unlikely that you did any damage. More likely, you didn't connect it back together properly. Make sure all the connectors between the motor and controller are fully home and tight.

 

[AC9999]

They all were. First thing I checked was all wires and connections. But the motor has the resistance when plugged in so that points to blown fets. Right?

 

[wesnewell]

It points to a short of the phase wires. Since you worked on it I'd suspect a solder bridge or wire short somewhere, but it could be a blown fet, or both.

 

[AC9999]

when it's ok without controller connected then motor is ok, but with controller connected has resistance then FETs are blown.
Might be just one, might be several. Usually will all be on one phase.
Could be from original problem, or could be from mods...

It points to a short of the phase wires. Since you worked on it I'd suspect a solder bridge or wire short somewhere, but it could be a blown fet, or both.

I've also read on several other posts that it is probably blown FETs. I'm going to go follow through on that thought process first and see if it solves it. So does anybody think that the main issue in the first place was a single blown fet causing that half amp problem?

Is the only way to test the FETs by removing them from the PCB and checking the continuity between the G D S or is there a way while they are sill installed?

Any opinion on the replacement FETs or caps I was looking at on the mouser site?

I appreciate all the help guys. Thanks

 

[spdas]

Aloha, with my limited knowledge I have found the following situations, even though my setup is not similar with PAS and battery voltage.

case 1) My one motor would only go 15-17mph or so and finally I got it to go 25mph. Reason was the B G Y combination with phase and Hall. I thought I tried EVERY combination using a chart, but the 5 best ones that worked without grinding or heating up were 4 combos @ 15mph and the one at 25 mph

case 2) I had to specify a slow or fast RPM motor when I ordered my Leaf motor. And ordered a thermal probe inside the hub

case 3) My 14" rim with 64Volts and 1000watt motor will rip along at 30mph+, but if I put my 16" rim on with smaller 350-500 Watt hub I get only 17-18 mph max. (You would figure having the same controller and battery for both motor combinations would make the larger 16" wheel spin the same rpm and result in faster MPH!!) I know that the smaller motor could burn out at the higher speed.

Anyways my observations

francis

 

[AC9999]

It's a plug and play system so no way to reverse any wires but the 2 power ones to the controller. And those are fine.
It came on a 26 and all settings are correct. It's a bad controller.
FETS are now blown.