QS273 vs 4AWG pics

[dominik h]

Measured with a temperature sensor attached to the phase wires.
I also tried to separate the wires from each other. But there was not much space.

 

[Comrade]

Measured with a temperature sensor attached to the phase wires.
I also tried to separate the wires from each other. But there was not much space.

What kind of insulation do those wires have?

 

[ebike11]

Measured with a temperature sensor attached to the phase wires.
I also tried to separate the wires from each other. But there was not much space.

Ok i see...so the temperature dropped to 140C??

 

[dominik h]

I think phase wires on my 5kW QS have an insulation rated for 180C. I tested the wires with a solder iron, above 250C they beginn to melt.
My new ones are rated 205C , melting starts here above 300C. The new wires are made in Germany.
There also exist 300C wires but the silicone-like insulation is very sensitive to cuts. These 205C wires have a very robust insulation.

I did the same "test" ride after getting rid of the protetive hose.
While normal use my wires stay below 130C.

 

[ebike11]

I think phase wires on my 5kW QS have an insulation rated for 180C. I tested the wires with a solder iron, above 250C they beginn to melt.
My new ones are rated 205C , melting starts here above 300C. The new wires are made in Germany.
There also exist 300C wires but the silicone-like insulation is very sensitive to cuts. These 205C wires have a very robust insulation.

I did the same "test" ride after getting rid of the protetive hose.
While normal use my wires stay below 130C.

Thx
Yes the 4awg I got is nice and flexible but like you said they are sensitive to cuts. Mine are rated 200c. The insulation Im assuming.

I will test as well in the future. I think though its hard to do the exact same test twice....it is hard to do an exact duplicate test run

Which qs model do you have?

 

[Comrade]

That's some Chinese engineering to run wires near jacket melting point.

Maybe get a few of these and zip tie them strategically to the frame, so they keep the wires apart for better cooling.

 

[dominik h]

You are right there is no posibillity to do two identical runs.
The road I drove is a very narrow and curvy, it is an uphill drive for about 15Minutes. Riding time difference between the two tests was only a few seconds.
The motor runs all the way uphill with the max phase current the controller can provide until there is no more rise of the temperature.

The motor is QS260, 10 year old 13" marked with QS60V5000W, there is no marking if it is a V2 or V3 or something else. Phase wires are AWG4 16mm²
This motor was installed in my 60V40Ah Lifepo4 Scooter with 80A Controller, and there it never got warm.
Now it is installed in a Masini Extremo (produced by EFun Mountain Chen) with SVMC72150. Before it ran a few miles with a SVMC72260, but the big controller died during a no load test with activated flux weakening. Before it gave me uphill a solid 220A battery current ( 18kW) and 450A phase current, 21S100AH Li-NMC battery. Same happend to the first SVMC72150 drove 4 weeks without any problems and then it died during a no load test. No load + activated flux = dead.

The actually installed SVMC72150 gives me a solid 165A battery current, peaks around 175A, but its due to its limited phase current 350Apeak/250Arms a liitle weak from a standstill.

The motor which was originaly in the Masini Extremo had two times AWG10 per phase and was sold as 8kW (72V/60Ah Lifepo Battery)
This motor will get installed when the rear tire is worn, or the new Fardriver ND96850 controller arrives.

 

[ebike11]

. Phase wires are AWG4 16mm²

Do you mean AWG4 is your upgraded phases? If so, isnt it bigger than 16mm? QS says 16mm is what the stock size phases are

 

[dominik h]

Sorry looked at a wrong conversion list, which says 16mm=awg4.
Phase wires are 16mm upgrade is 2x16 205C wires per phase.
Hope it is enough fü1r the Fardriver ND96850, and I have to Insert temperature Sensors n my Motors to present them from overheating wires and magnets.

 

[ebike11]

Sorry looked at a wrong conversion list, which says 16mm=awg4.
Phase wires are 16mm upgrade is 2x16 205C wires per phase.
Hope it is enough fü1r the Fardriver ND96850, and I have to Insert temperature Sensors n my Motors to present them from overheating wires and magnets.

Are your AWG4 the same size as mine in my photos?

 

[dominik h]

Who can estmate with a picture.
Awg4 = 21,2mm
Awg5 = 16,8mm my new ones are multinorm wires so they have to be the same as AWG5

So the ones in my QS have to be smaller than your AWG4 .

 

[ebike11]

Who can estmate with a picture.
Awg4 = 21,2mm
Awg5 = 16,8mm my new ones are multinorm wires so they have to be the same as AWG5

So the ones in my QS have to be smaller than your AWG4 .

Yes hard with pics.
My silicone wires are nice and flexible but VERY easy to slice open. I got to be careful when mounting them

 

[ebike11]

Thanks for the advice..my main purpose is to use the 4awg as a heatsink when crimping the qs273 wires to it around 15cm outside of the hub. The 4awg will extend to around 80cm to the controller at the front of the bike. Im unable to put the controller any closer to the motor

I'm sorry, maybe I'm too new to all of this, but what do you mean when you say you want to use a cable as a heatsink?

Copper is not only a good electrical but also heat conducting material. So the heat in the motor can find it's way outside through the phase wires.

@ebike11:
I hope you're aware of "Statorade" to help cool a hub motor even better? Maybe even add "Hubsinks".
https://ebikes.ca/product-info/grin-products/statorade.html

I thought there was some terminology I was missing here. I didn't realize people are trying to use copper cables as some thermal vacuum.

Sure, copper's a great thermal conductor, but 3X4AWG amounts to less than 1cm2 of cross-section area. That's about the size of your pinky fingernail. Heat is supposed to flow up that narrow channel? If we were talking about a span of a millimeter, that might make sense, but over tens of cm? There's absolutely no way this will reduce even 0.1degC off the engine.

Say I hold a 50cm copper rod with a 1cm2 in cross-sectional area. I put one end in 95degC (the motor end) and the other end at 20degC. How much power will the rod "pull" across it? That's the temp diff multiplied by the cross-sectional area and the thermal conductivity of copper divided by length of the rod. Or 75degC * 1cm^2 * k_copper / 0.5m = 0.015*k_copper Watt. k_copper is ~400 W/mK. So that's 6W of power "pulled" across the rod. We can assume that the rod is mostly cold by 25cm, since it's open air, but we'll still get just 12W.

Even a rod of 5cm only gets us 60W, and at this point how do you even keep the cool end from heating up when it's drawing constant 60W (it's basically a soldering iron at this point).

No. Using cables to cool down a motor won't work.

https://endless-sphere.com/forums/viewtopic.php?t=30127

 

[neowizard]

I thought there was some terminology I was missing here. I didn't realize people are trying to use copper cables as some thermal vacuum.

Sure, copper's a great thermal conductor, but 3X4AWG amounts to less than 1cm2 of cross-section area. That's about the size of your pinky fingernail. Heat is supposed to flow up that narrow channel? If we were talking about a span of a millimeter, that might make sense, but over tens of cm? There's absolutely no way this will reduce even 0.1degC off the engine.

Say I hold a 50cm copper rod with a 1cm2 in cross-sectional area. I put one end in 95degC (the motor end) and the other end at 20degC. How much power will the rod "pull" across it? That's the temp diff multiplied by the cross-sectional area and the thermal conductivity of copper divided by length of the rod. Or 75degC * 1cm^2 * k_copper / 0.5m = 0.015*k_copper Watt. k_copper is ~400 W/mK. So that's 6W of power "pulled" across the rod. We can assume that the rod is mostly cold by 25cm, since it's open air, but we'll still get just 12W.

Even a rod of 5cm only gets us 60W, and at this point how do you even keep the cool end from heating up when it's drawing constant 60W (it's basically a soldering iron at this point).

No. Using cables to cool down a motor won't work.

https://endless-sphere.com/forums/viewtopic.php?t=30127

Sorry, I'm not sure what you're suggesting with this post-link.

From a brief reading, it looks like they're talking about reducing wire-losses and wire heat by going higher gauge. That's totally a thing, but won't cool your motor unless you replace the wires inside the motor. Bumping up the wire-size outside the motor will not cool the motor at all.

There were some suggestions there that say you can sink heat with thick wires. They're just wrong, and provide no data or basis to support that, though.

 

[Chalo]

From a brief reading, it looks like they're talking about reducing wire-losses and wire heat by going higher gauge. That's totally a thing, but won't cool your motor unless you replace the wires inside the motor. Bumping up the wire-size outside the motor will not cool the motor at all.

No, but it can help sink any heat developed in the through-axle wires (if that's the key issue).

 

[ebike11]

I thought there was some terminology I was missing here. I didn't realize people are trying to use copper cables as some thermal vacuum.

Sure, copper's a great thermal conductor, but 3X4AWG amounts to less than 1cm2 of cross-section area. That's about the size of your pinky fingernail. Heat is supposed to flow up that narrow channel? If we were talking about a span of a millimeter, that might make sense, but over tens of cm? There's absolutely no way this will reduce even 0.1degC off the engine.

Say I hold a 50cm copper rod with a 1cm2 in cross-sectional area. I put one end in 95degC (the motor end) and the other end at 20degC. How much power will the rod "pull" across it? That's the temp diff multiplied by the cross-sectional area and the thermal conductivity of copper divided by length of the rod. Or 75degC * 1cm^2 * k_copper / 0.5m = 0.015*k_copper Watt. k_copper is ~400 W/mK. So that's 6W of power "pulled" across the rod. We can assume that the rod is mostly cold by 25cm, since it's open air, but we'll still get just 12W.

Even a rod of 5cm only gets us 60W, and at this point how do you even keep the cool end from heating up when it's drawing constant 60W (it's basically a soldering iron at this point).

No. Using cables to cool down a motor won't work.

https://endless-sphere.com/forums/viewtopic.php?t=30127

Sorry, I'm not sure what you're suggesting with this post-link.

From a brief reading, it looks like they're talking about reducing wire-losses and wire heat by going higher gauge. That's totally a thing, but won't cool your motor unless you replace the wires inside the motor. Bumping up the wire-size outside the motor will not cool the motor at all.

There were some suggestions there that say you can sink heat with thick wires. They're just wrong, and provide no data or basis to support that, though.

But at least there is a benefit..even if its outside the motor. Id rather have a meter of 4awg than 12awg

 

[neowizard]

Sorry, I'm not sure what you're suggesting with this post-link.

From a brief reading, it looks like they're talking about reducing wire-losses and wire heat by going higher gauge. That's totally a thing, but won't cool your motor unless you replace the wires inside the motor. Bumping up the wire-size outside the motor will not cool the motor at all.

There were some suggestions there that say you can sink heat with thick wires. They're just wrong, and provide no data or basis to support that, though.

But at least there is a benefit..even if its outside the motor. Id rather have a meter of 4awg than 12awg

Yes, that's fair. I'd focus my efforts and money elsewhere, TBH, but to each their own.

I mainly posted here to quell that belief that you can sink heat through a 1cm^2 cross section of copper - which you can't in any meaningful quantity.

 

[ebike11]

Sorry, I'm not sure what you're suggesting with this post-link.

From a brief reading, it looks like they're talking about reducing wire-losses and wire heat by going higher gauge. That's totally a thing, but won't cool your motor unless you replace the wires inside the motor. Bumping up the wire-size outside the motor will not cool the motor at all.

There were some suggestions there that say you can sink heat with thick wires. They're just wrong, and provide no data or basis to support that, though.

But at least there is a benefit..even if its outside the motor. Id rather have a meter of 4awg than 12awg

Yes, that's fair. I'd focus my efforts and money elsewhere, TBH, but to each their own.

I mainly posted here to quell that belief that you can sink heat through a 1cm^2 cross section of copper - which you can't in any meaningful quantity.

Of course im using hub sinks and ferrofluid. I just wanna do as much as possible since the motor will see 30kw from time to time in bursts

 

[Chalo]

I just wanna do as much as possible since the motor will see 30kw from time to time in bursts

Accept the consequences and learn from them, faraway friend.

 

[ebike11]

I just wanna do as much as possible since the motor will see 30kw from time to time in bursts

Accept the consequences and learn from them, faraway friend.

Who said im not accepting them? Thats why im doing my best to limit negative consequences.

Whats faraway?

 

[calab]

Location: far away

Whats faraway?

 

[ebike11]

Location: far away

Whats faraway?

Oh...never seen posters on here put their location name when referring to them

 

[calab]

True, at best you could hope for a country then a state then a city then gps coordinates.

Location: far away

Whats faraway?

Oh...never seen posters on here put their location name when referring to them

 

[ebike11]

True, at best you could hope for a country then a state then a city then gps coordinates.

Location: far away

Whats faraway?

Oh...never seen posters on here put their location name when referring to them

GPS??? To send a hitman..no thx jk

 

[calab]

Yes, gps
Someone put their gps coordinates as their location.
Another put their location in space something like Milkyway or something.
Might have been Dauntless - https://endless-sphere.com/forums/memberlist.php?mode=viewprofile&u=16196

Location:
Coordinates: 33°52′48″N 117°55′43″W

Milkyway deal might be Amberwolf
https://endless-sphere.com/forums/memberlist.php?mode=viewprofile&u=13812

Location:
Phoenix, AZ, USA, Earth, Sol, Local Bubble, Orion Arm, Milky Way, Local Group

Pretty spot on lately.
Half the time :wink:

I thought it was worded differently, might have changed it in the last 1-2yrs, or there might be another astronaught amongst us.

Sorry for going off topic. I shouldnt mess up the thread, but we can be light hearted.

Has anyone made their own axle for the QS, I know someone did for the mxus. Someone with machine shop tools and time.
Also makes ya wonder who's got the biggest gauge of phase wires here?

GPS??? To send a hitman..no thx jk