Hot phase wires and only half speed

Hi experts!

Just replaced my fried China hub motor (brushless 1000w) with a new similar one. The motor ran backwards when using the matching colors so I made the switch suggested by the troubleshooting guide here (yellow and green on hall wires and yellow and blue on phase wires) and got smooth forward movement.

But - the phase wires are getting hot, especially one, when running the motor at full speed even without load, and the motor seems to be running only at half speed. Could this be due to wrong wiring, is it a common issue?

How many amps does the system pull from the battery when spinning in air?

If you don't know, you'll need something like this:

http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR1.TRC0.A0.H0.Xgt+power+meter.TRS0&_nkw=gt+power+meter&_sacat=0

It's also possible to insert a DVM and use the 10A function but that may be easier said than done. The system shouldn't draw much more than 2A spinning no load.

How much heat's too much is hard to judge feeling wires? One being hotter than the others is probably not a good thing but without any tools of reference (Amp draw, for example) we're gonna type a lot of words and still not be able to burrow down to the root problem(s). If any.

Thanks for your answer!

My meter says maximum 200mA so I will have to get something better, like the one you suggested. I could always try other wire combinations but I don't want to unless I absolutely have to...

The amount of heat can be described by the wires getting too hot to comfortably hold with a tight grip. I am not sure about one getting hotter than the others, now they all felt pretty hot. Could it be a case of too long and too thin wires? I plan to cut at least 15" off the phase wires.

utsi said:

Hi experts!

Just replaced my fried China hub motor (brushless 1000w) with a new similar one. The motor ran backwards when using the matching colors so I made the switch suggested by the troubleshooting guide here (yellow and green on hall wires and yellow and blue on phase wires) and got smooth forward movement.

But - the phase wires are getting hot, especially one, when running the motor at full speed even without load, and the motor seems to be running only at half speed. Could this be due to wrong wiring, is it a common issue?

Click to expand...

You must still have the wrong connection sequence. Try other combinations until it's OK.

For testing phase / hall combos it is best to use a small fuse like @ a 5 amp or so.
Full throttle accel with a wrong wiring combo can pop fets in the controller.
A hot phase wire while testing no load is a sign of a bad combo.

Good luck.

Thanks!

I guess it takes a lot more than 2A to make the wires so hot. I consider myself lucky that I didn't break anything!

Since I don't have any fuses I will buy an ampere meter tomorrow or on Monday and report back.

My bet also is that you have a bad combo. But it could be just one bad contact in a plug getting hot. Heating up just one wire sort of points to that.

Check for the plug, less power could just be because you are running on two phases, while the power on the third heats up the plug, and the wire.

If not that, then try other combos, look for one that runs on low wattage no load.

I purchased an ampere meter today and you were right. The bike was drawing more than 15A even at very low speed.

Got the wires right at my 6th attempt!

Thank you very much for your help!

My general recommendation for any new E-biker is to buy the throttle/controller/motor from the same vendor. That way, the connectors are 99% likely to pop right together (the style of connector matches) and usually, everything matches right from the start.

All batteries that are made for kits have two fat wires, and on of the ONLY standards that the various China manufacturers follow is the RED/BLACK for POS/NEG on the battery wires. (some factory E-bike batteries has several small wires, battery temp, state of charge, etc)

I often replace the main connectors between the battery and controller with my favorite XT90. That being said, I am dismayed and annoyed that more manufacturers haven't embraced a standardized color-code for the 5 hall wires. One wire supplies 5V positive for all three hall sensors, one wire provides negative (ground?) for all three sensors, and the remaining three are for the pulse signal that the hall sensor sends back to the controller. If the 5V pos can be determined, and the negative ground can be determined, the three remaining signal wires are the only ones that need to be sorted to find the correct sequence.

I hold no hopes of EVER persuading 90% of kit manufacturers to use the same 5-pin connector (there will always be at least a few that choose an odd connector that is a few pennies cheaper than the standard). But the color-codes? black-red for the two power wires, and blue/green/yellow seem to be common for the three signal wires.

Someone (maybe us?) needs to start a grass roots campaign to establish which hall sensor should be assigned blue/green/yellow. Due to the disc brake mounting flange, all hubs (front or back) have an easily recognized normal rotation, and since most bicycles are mounted from the left, and the sideplates seem to be most often removed from the left side...I propose that: when looking at a hubmotor stator from the left side, and you visualize the locations of the hall sensors starting from the first one encountered when moving around the rim clockwise...they be assigned Blue/Green/Yellow, in that order (alphabetical, BGY, easy to remember that way).

Let's hope one or two asians are sharing our frustrations about the colours! My new motor actually had 6 hall wires. The extra one seemed to be ground, but I haven't measured if anything happens there under load.

Took the bike for a short test drive yesterday and everything seemed OK except I didn't quite reach the same speed as with my previous motor! My previous gave me 50km/h but this one only 46km/h. I thought 1000W was 1000W, is it usually any difference between these units?

Motors come in different rpm's. so depending on the winding, they are fast or slow.

You can buy controllers now, that self study and work out the combo themselves. But yeah, I always wonder why it's so hard to come up with a standard for which hall sensor and which wire to the controller is B Y G.

Hopefully it will make up for the slow performance on flat surface by being stronger uphill then..

Ordered a new battery today because I want to retire my 10kg backpack battery. Has anyone tried these?:

http://www.ebay.com/itm/like/2015-48V-12AH-Samsung-INR18650-29E-Cell-Down-Tube-Frame-Li-ion-Battery-Akku/181730413030?hlpht=true&ops=true&viphx=1&_trksid=p2050601.c100103.m2451&_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D20140211150826%26meid%3D431e25565d8b4374a0d2d69b9a3d3a93%26pid%3D100103%26rk%3D1%26rkt%3D4%26sd%3D181730413030%26clkid%3D5906144422387679797&_qi=RTM2010736

3.5kg on the frame sounds more comfortable than 10kg on my back!

the 6th wire may be the thermistor inside the hub. measure the resistance between that wire and your black wire.

Many motors have a speed sensor as the 6th wire. It will pulse on and off with 5v if measured to ground when the controller is switched on and you rotate the motor backwards.

Sometimes the wire is in the harness, but not connected to anything. That's if they use a standard harness and the motor has no speed or temperature sensor.

Did not look more into the 6th wire, will investigate more if I ever get a controller with 6 wires.

Thank you for your help!