[green caveman]

Have the 11" GE Sepex from this thread. Pack voltage nominal 106 (33x 100Ah thundersky). It was at 111V for these tests. Chennic controller (I've been impressed by the price/quality of Chennic products).

This build has been going on for while (to put it nicely). Today, we wired up the motor and controller. Donor is a 1994 4WD Suzuki Sidekick.

Put the back end on stands, the motor ran, but the wheel ran backwards. Put the forward/reverse contactor in reverse, now the wheels run forwards. (Runs fine in neutral, etc. etc.). Haven't checked diligently (like taking the brush covers off), but there doesn't seem to be obvious sparking. The motor had a major overhaul, new bearings, cleaned, new brushes, rewound armature (did have a short) so I suspect it's about as good as that motor gets.

Put the car on the ground, and it lurches forward a few inches and then stops. The clutch is not connected, and the tranny didn't want to go into first (maybe the root cause?) so this was in second gear.

According to the programmer attached to the controller, the field current was ~30A BUT the motor current was reporting 350A, which I find unlikely, and the voltage is being reported as 44V, so maybe a controller issue in play and all the numbers are wrong.

However, if we run the motor forwards, the car is now in reverse but going forwards. It seemed to run fine for the short distance we ran it. (Maybe a little slow, but we didn't run it far or fast because I'm not sure this is good for the tranny to be running backwards).

Is it possible that the configuration for the motor is different for backwards and forwards? Or is it possible that it's just the lower reverse gear would make such a difference?

Is reversing the motor as easy as switching A1/A2 or do I need to switch the field coils or something completely different?

Thanks,

[major]

Originally Posted by green caveman

According to the programmer attached to the controller, the field current was ~30A BUT the motor current was reporting 350A, which I find unlikely, and the voltage is being reported as 44V, so maybe a controller issue in play and all the numbers are wrong.

However, if we run the motor forwards, the car is now in reverse but going forwards. It seemed to run fine for the short distance we ran it. (Maybe a little slow, but we didn't run it far or fast because I'm not sure this is good for the tranny to be running backwards).

Is it possible that the configuration for the motor is different for backwards and forwards? Or is it possible that it's just the lower reverse gear would make such a difference?

Is reversing the motor as easy as switching A1/A2 or do I need to switch the field coils or something completely different?

Thanks,

To reverse motor rotation, switch either the armature or field polarity, not both. I think this GE motor was from a forklift so would likely be neutral timed, that is the same either rotation.

And 30A field current for 350A armature could be the source of poor torque. I looked at the ad for the controller and didn't see where it had provisions for field map programming. I'd get higher field current for high armature currents.

[green caveman]

Originally Posted by major

To reverse motor rotation, switch either the armature or field polarity, not both. I think this GE motor was from a forklift so would likely be neutral timed, that is the same either rotation.

And 30A field current for 350A armature could be the source of poor torque. I looked at the ad for the controller and didn't see where it had provisions for field map programming. I'd get higher field current for high armature currents.

I've been looking for the manual, and have asked Chennic again. There seems to be a large number of parameters, including (IIRC) "Field Map" field with a value of 120A. No idea what this means or what the limits are.

If I can't find the manual, I'll go through the other parameters and see if any ring a bell with you or anyone else. There are acceleration percentages, and similar as well as a number of regen related values. (It's too dark to get the values now, plus it's taken the whole day to finishing wiring all this up!).

I haven't looked at the spreadsheet that was developed for that motor, but my recollection is that 50A represented the knee in the curve. I'm not trying to build a hotrod, but would it be reasonable to expect that much loss of torque (non-linear?).

[green caveman]

I think I lost a post, but if this is a dup, please let me know.

With the field parameter set to the maximum the controller permits (40A) there's enough power to move the vehicle. The controller is still reading a battery voltage of 44V, no word from Chennic yet on why.

I've ordered a 50A shunt since I'd be very surprised if the field is getting 40A (and the armature 350A) with so little power. The 35kW would have to go somewhere and it's not into motive power and nothing seems to be getting hot. Our guess is that the power is correct if the voltage were 44V, so scale by 44/110 = 0.4 and you have 16A of field and 140A in the armature - just a guess.

[green caveman]

We took the cover off the brushes on the motor last night to watch for sparks. The motor is 36/48V and we're running it at (we hope) nominal 105V (Li).

Running in neutral, or just slowly backwards and forwards we saw no arcing, sparking, whatever, at all.

Is there anything more we should do to make sure that this motor is going to work for us before (possibly) replacing the controller?

The big Sepex has been the risk all along since we have to run it at 2x rated voltage without advance. So far, it seems good. Going downhill you can feel the effect of regen. Since it's hilly here, the purpose of regen is mostly to save the brakes, but any bonus range is fine.

[onegreenev]

Running your motor at 96 volts neutral should be NO problem. I have a 9" GE and have run that with no problem at 96 volts and 700 amps. GE motors are very good motors and very stout and well built. I recommend them if you can find them. SepEx or Series. Mine are series GE motors. I have two.

[onegreenev]

Yes my GE 9" is neutral timed.

[green caveman]

Originally Posted by onegreenev

Yes my GE 9" is neutral timed.

Good to know. I don't know enough about motors to understand what parameters allow them to run at high voltage with neutral timing, but have heard reports of people running neutral forklift motors to 120V without a problem (that's partly what lead me to think the SepEx should work).

We hadn't really looking inside the motor since the shop reassembled it. But with a renewed armature, new brushes and cleaning (steam?), it looks really nice in there. Who knew that the field coils were red and not black!

[onegreenev]

Color of the field windings are a result of the lacquer used to coat the whole thing. I think the neutral timing should still be OK at 120 volts. Beyond that they should be advanced a bit. I have a Kostov that is slightly advanced but these have interpoles which help so you don't really need to advance much at higher voltages. So far at 120 volts the Kostov is working fine. I will be bumping it to 156 here shortly and doing a video run.

[green caveman]

Originally Posted by onegreenev

Color of the field windings are a result of the lacquer used to coat the whole thing.

Well, hopefully, the brush dust from driving will turn them black again before too much longer!