What thermistor does QS273 use?

[harrisonpatm]

I have a QS273 8000w, and on my new build I am occasionally pulling 8-10kw for a few minutes or more. The motor gets noticeably hotter than it did on my slower build. If I put my hand on it, I can hold it there, and it's hot, but not painfully so. I'd guess 60 degrees C, no more than 80. I've set my controller to reduce power if the motor gets to 75 C. But I don't have a display, so I don't know what the motor tempt ever actually is. I've never had a cutout before, but it'd be nice to know temp. I've seen before on the forum people who have been able to simply wire in a thermistor and have a digital readout on their dash (I think it was @Dui ni shuo de dui who modded a BBQ thermometer?).

However, the QS273 has dual hall sensors and connectors, redundant. Meaning, in the spare connector coming from the motor, there's idle wiring leading to a spare thermistor that's already installed in the motor. But I don't know what kind it is.

I just tested on a cheap digital temp display that uses a 10k thermistor, connecting its thermistor jack wires to the spare thermistor in the motor, but the temp was displaying 90 C, obviously wrong. Does anybody know what thermistor is used? Or, does anybody know of a cheap thermometer display that would use the same type of thermistor that's already in the motor?

 

[dominik h]

You just have to Check the resistance at 20C to know.

My new 10kw Qs273 has kty83-122 installed

 

[harrisonpatm]

Cool, never heard of that kind of thermistor before. Anybody know a cheap readout that uses that type of thermistor?

 

[E-HP]

Cool, never heard of that kind of thermistor before. Anybody know a cheap readout that uses that type of thermistor?

Maybe check with AGS to see if he did research before deciding to change the sensor out.

Risunmotor Sabvoton 72100 Controller Temperature Settings

Hi all I have come across a problem with my controller when I try to set temperature settings using the MQCON app and they won’t save. I also only have one set of temperature configurable settings on the app for my iPad, Teranovo version. I have seen some screenshots of two sets, one for the...

endless-sphere.com

 

[AGS]

I have a QS205 motor and I swapped out the KTY83-122 with a NTC 10K and rewired the motor wiring slightly so the sensor uses both temperature wires to feed a temperature controller mounted on my cockpit.

There are plenty of cheap displays and temperature controllers that work with the NTC 10K on eBay, but I couldn’t find anything that works with the KTY 83.

I’m pretty sure the QS273 is wired the same as the QS205.

I did this because my Sabvoton 72100 doesn’t have the ability to measure motor temperature.

The KTY83 has two signal wires connected to one side of the thermistor that go to each hall plug and the other side of the thermistor is connected to ground. So I removed the ground wire and connected one signal wire to each side of the NTC 10K and removed each wire from the hall plugs and fed them directly to the temperature controller mounted on my cockpit.

I also fitted a NTC 10K inside the motor controller so I can monitor both motor temperature and controller temperature on my cockpit with an alarm set at 70C for the controller and 90C for the motor.

It works very well and I don’t suffer from any electromagnetic interference, so the temperature monitor is stable. It’s surprising how quickly the motor temperature rises when used in anger and I think monitoring motor temperature is a must have on these motors if they are used hard.

Here is my bike, it pulls 7.5Kw

 

[harrisonpatm]

I did read through your post, but I was hoping to not have to open the motor again. Or, didn't want to remove the temp sensor, in case I ever need to swap to that set of halls again.

 

[AGS]

Swapping to the spare hall sensor plug isn’t a problem with the wiring and temperature sensor modification. but opening the motor to carry out the modification is a bit of a pain, especially with a QS273.

I had to open my motor several times during my build for various reasons, but now it’s finished I hope I don’t need to open it again for a long time.

I used a 3 jaw puller on my QS205 and that was fiddly enough. I had to use cable ties to stop the jaws from spreading and slipping.

If you can find a display that works with a KTY83-122 then let us know because I couldn’t find one anywhere without having to build an electronic circuit.

 

[harrisonpatm]

Swapping to the spare hall sensor plug isn’t a problem with the wiring and temperature sensor modification. but opening the motor to carry out the modification is a bit of a pain, especially with a QS273.

I had to open my motor several times during my build for various reasons, but now it’s finished I hope I don’t need to open it again for a long time.

I used a 3 jaw puller on my QS205 and that was fiddly enough. I had to use cable ties to stop the jaws from spreading and slipping.

If you can find a display that works with a KTY83-122 then let us know because I couldn’t find one anywhere without having to build an electronic circuit.

Will do. I think at this point, I'll run the motor for the rest of the season and pop the cap off during the winter. I should be able to just add a 10k thermistor somewhere next to the windings, and run 2 small extra wires out of the axle.

 

[Dui ni shuo de dui]

I have a QS273 8000w, and on my new build I am occasionally pulling 8-10kw for a few minutes or more. The motor gets noticeably hotter than it did on my slower build.

This is a bit strange, with a QS273 8000W you should be good for more than 20KW without any kind of problem.
Do you know how many turns per coil you have? There are various possible configurations for this motor, do you remember which one you asked QS to make for you?

If I put my hand on it, I can hold it there, and it's hot, but not painfully so. I'd guess 60 degrees C, no more than 80. I've set my controller to reduce power if the motor gets to 75 C. But I don't have a display, so I don't know what the motor tempt ever actually is. I've never had a cutout before, but it'd be nice to know temp. I've seen before on the forum people who have been able to simply wire in a thermistor and have a digital readout on their dash (I think it was @Dui ni shuo de dui who modded a BBQ thermometer?).

Yes indeed, that was me. It still works great to this day, I can recommend this method.

However, the QS273 has dual hall sensors and connectors, redundant. Meaning, in the spare connector coming from the motor, there's idle wiring leading to a spare thermistor that's already installed in the motor. But I don't know what kind it is.

Yes, but I seem to remember you can't use them both at the same time because of the way they are wired.
You are very likely to need to open your motor to either wire them differently, or to just add another sensor.

I just tested on a cheap digital temp display that uses a 10k thermistor, connecting its thermistor jack wires to the spare thermistor in the motor, but the temp was displaying 90 C, obviously wrong. Does anybody know what thermistor is used?

If I remember correctly it is just the standard 10K NTC, one of the most basic and widespread sensors.

Or, does anybody know of a cheap thermometer display that would use the same type of thermistor that's already in the motor?

Unfortunately you'll have to open the motor if you want the sensor to work with both the controller and a display.
It is not extremely difficult to do IF you get the proper tool. Without the tool it is still doable by throwing the motor to the ground, but it becomes very difficult, plus it increases the change of damage to the motor a lot.

I'm talking about these 3 jaws bearing extractors:

First, I suggest you mark the exact position of your motor covers relative to the rotor. This way you are sure to put them back exactly the way they were.

With the brake disc in place, you use the extractor to push the stator out of the rotor (I suggest using an old disc brake because it can sometimes bend the disc, the forces are huge).

Then once the stator is out you will need to add two new wires through the axle. The method I use is to attach the two new wires to a TIG welding filler rod (some kind of stiff but thin and fexible metal rod), and then push the metal rod through the axle's silicon potting until it comes though the other side, taking care not to damage the other wires's insulation.

Once this is done you install the sensor somewhere by buriying it as deep as possible into a coil. Take care not to damage anything of course. You can secure it with a bit of silicone.

Finally you can reassemble the motor. Either drop the stator into the rotor, which is very scary (don't get your finger anywhere near the magnets), or you can reinstall the core the same way you took it out, with the extractor.
Make sure you 100% cleaned the mating surfaces of the covers as well as the mating surfaces of the rotor before you reinstall the covers. Any dirt or residual debris can mess up the alignment, which will lead to a slightly inconsistent motor gap (which isn't too much of an issue) as well as mess up the brake disc alignment (which is a bigger problem because then the brake disc wobbles, creating noise and poor braking performance).

With the proper tools and patience this can take less than one hour. If it's the first time it will probably take a whole afternoon.

 

[harrisonpatm]

This is a bit strange, with a QS273 8000W you should be good for more than 20KW without any kind of problem.

I agree that I'm good, I was simply comparing it to the fact that on my last build, I was really only giving it a max of 5-8kw, and it barely got warm. Now that I'm actually putting it to use, it's getting warm, normally so, nothing crazy.

Yes, but I seem to remember you can't use them both at the same time because of the way they are wired.

I can, at least on my motor, because either set is a totally different set of sensors, wired into either side of the stator.

If I remember correctly it is just the standard 10K NTC, one of the most basic and widespread sensors.

It's not, on mine at least, already tested.

Unfortunately you'll have to open the motor if you want the sensor to work with both the controller and a display.
It is not extremely difficult to do IF you get the proper tool. Without the tool it is still doable by throwing the motor to the ground, but it becomes very difficult, plus it increases the change of damage to the motor a lot.

I'm talking about these 3 jaws bearing extractors:

First, I suggest you mark the exact position of your motor covers relative to the rotor. This way you are sure to put them back exactly the way they were.

With the brake disc in place, you use the extractor to push the stator out of the rotor (I suggest using an old disc brake because it can sometimes bend the disc, the forces are huge).

Then once the stator is out you will need to add two new wires through the axle. The method I use is to attach the two new wires to a TIG welding filler rod (some kind of stiff but thin and fexible metal rod), and then push the metal rod through the axle's silicon potting until it comes though the other side, taking care not to damage the other wires's insulation.

Once this is done you install the sensor somewhere by buriying it as deep as possible into a coil. Take care not to damage anything of course. You can secure it with a bit of silicone.

Finally you can reassemble the motor. Either drop the stator into the rotor, which is very scary (don't get your finger anywhere near the magnets), or you can reinstall the core the same way you took it out, with the extractor.
Make sure you 100% cleaned the mating surfaces of the covers as well as the mating surfaces of the rotor before you reinstall the covers. Any dirt or residual debris can mess up the alignment, which will lead to a slightly inconsistent motor gap (which isn't too much of an issue) as well as mess up the brake disc alignment (which is a bigger problem because then the brake disc wobbles, creating noise and poor braking performance).

With the proper tools and patience this can take less than one hour. If it's the first time it will probably take a whole afternoon.

I've already opened it twice on two different occasions, I'd just rather not open it again unless I need to. Hence me waiting until I need to, and hoping that I can use the sensor as it.