Upgrading the phase wires on an X5302

[markcycle]

I melted the phase wires for the last time (I hope). I am running 90 amps and using regen with a Kelly controller. I finally upgraded the phase wires so I hope I never have to open up this motor again (this was the 4th time) see pictures. The windings never seem to burn but I cooked the Halls once and melted the phase wires 3 times. Introducing regen seemed to put the situation over the top and raised the motor about 10C over what I normally run, which was about 60 to 65C case temp after I stopped and waited ten minutes for the case temp to peak.

 

[ZapPat]

90 amps peak I guess, right? What's your average power going into the motor? Sounds powerfull, that's for sure...

One suggestion for avoiding melted phase wires: Use magnet type wire (same type as windings are made of) instead of plastic sheathed wire to get outside of your hub, then make external connections to your regular (and more flexible) plastic sheathed phase wires. I actually used three smaller gauge magnet wires for each phase going through the axle, but the total gauge equivalent for each phase is actually a bit bigger than the internal motor winding's magnet wire. This was to make sure that the fragile point was the motor windings themselves, not the phase output wires.

I also changed my hall sensor wires to small gauge magnet wire, since after changing the phase wires I ended up melting the plastic sheating on the hall wires too! Now I hope all is going to last for a while, and with winter arriving here I will be having a harder and harder time melting things anyways.

BTW I used plastic heatshrink tubing to protect the magnet wire going through the axle, as I was a bit woried of the enamel wearing off by rubing on the axles metal walls (specially around the bend going into the motor compartment).

I even added a temperature sensor inside while I was at it, but have not hooked it up yet...

 

[fechter]

........
I even added a temperature sensor inside while I was at it, but have not hooked it up yet...

That's what you need. You can pound amps through that thing when it's cold, but you don't want to allow it to ever get hot enough to fry the hall sensors, which will be the next weak link.

Doesn't the Kelly controller have an input for a temp sensor?

Ideally you'd want the controller to gradually reduce its current limit as the temperature increases above a certain point. With proper programming, you could make it nearly impossible to destroy the motor. In cold weather, you would probably not be limited.

 

[markcycle]

90 amps peak I guess, right? What's your average power going into the motor? Sounds powerfull, that's for sure...
..

No 85 to 90 amps continuous at 35 to 45 MPH. The reason I can get away with such big amps because I only do 90 amps at high speed where the motor is 80% or more eff. I'm still losing close to 900 watts at 90 amps at 80% eff so I'm thinking the motor is more like 85 to 90% eff (I hope)

At low speeds I use a boost motor thru the chain. If I didn't the motor would fry
I'v posted threads on my motorcycle build showing the boost motor.

Mark

 

[Link]

I'd strongly consider teflon wire. Most are good for over 200C, so you should never have a problem with them.

 

[knoxie]

Hi Mark

Hmm I think you are hitting the limit there on that X5, as Fechter says the hall sensors will be damaged if you get those windings too hot, the kind of continuous power you are pumping through it may be too much, others here do pump high powers through their motors but maybe not at the bike weight or for the duration that you are?

A temp sensor is a very good idea, it has saved 2 of my motors in the past, good luck and I really like your bike so I hope you dont have to open the motor again! its a pain only done it once on my X5 to waterproof it.

Cheers

Knoxie

 

[markcycle]

Hi Mark

Hmm I think you are hitting the limit there on that X5, as Fechter says the hall sensors will be damaged if you get those windings too hot, the kind of continuous power you are pumping through it may be too much, others here do pump high powers through their motors but maybe not at the bike weight or for the duration that you are?

A temp sensor is a very good idea, it has saved 2 of my motors in the past, good luck and I really like your bike so I hope you don't have to open the motor again! its a pain only done it once on my X5 to waterproof it.

Cheers

Knoxie

You and Fechter are right, I will need to open the motor one more time to install a thermistor some time this winter. So far, the only time I destroyed the halls is when my boost motor chain came off the sprocket and I ran only on the hub motor. That caused massive overheating and melted everything but the windings. But with the boost motor operational, its was just the leads that could not take the current and heating of the motor was relativity low compared to some of the temps I read about on this forum. I never got the case over 70C peak after shutdown and waiting for the case temp to peak. The X5 is a big motor and keeping it from the burden of locked stator high current and low RPM high current is the only reason it works for me. When my boost system failed I overheated the motor within a half hour of trying to get home in traffic.

Mark

 

[Doctorbass]

90 amps peak I guess, right? What's your average power going into the motor? Sounds powerfull, that's for sure...
..

No 85 to 90 amps continuous at 35 to 45 MPH. The reason I can get away with such big amps because I only do 90 amps at high speed

That's incredible to see that at 45mph the 5302 draw nearly 90A and that my 5305 at the same speed draw 26A at 95V...!

It's a great exemple of what winding you choose... so if you prefer low voltage and heavy wires.. then use the 5302-5303 and if you prefer smaller wire setup and lower current demand.. use the 5305...

I heard that all X5 motor use the same winding wire diameter.. and i measured it and it's AWG17 equivalent

My 5305 have 5 of that wire run in parallel

how many the 5302 have?.. i would say 8-9 ?

see the difference:


Doc

 

[markcycle]

90 amps peak I guess, right? What's your average power going into the motor? Sounds powerfull, that's for sure...
..

No 85 to 90 amps continuous at 35 to 45 MPH. The reason I can get away with such big amps because I only do 90 amps at high speed

That's incredible to see that at 45mph the 5302 draw nearly 90A and that my 5305 at the same speed draw 26A at 95V...!

It's a great exemple of what winding you choose... so if you prefer low voltage and heavy wires.. then use the 5302-5303 and if you prefer smaller wire setup and lower current demand.. use the 5305...

Doc

I respect your chose Doc but one could also say

If you prefer low safe voltages choose a 5302/5303 or if you prefer high lethal voltage levels choose a 5305
It is also wise to stay within the low voltage directive (48 volts) as defined by UL/CE safety marking.

Its a matter of design, copper is expensive so a balance needs to be had. It is easier to do higher voltage with the X5 since the slot in the axle isn't designed for heavy wire. I had the additional problem of running 2 motors and it is hard to find a good small 1000W brush motor higher than 48 volts.

I understand why you prefer high voltage and originally I wanted to use 60 volts but just could not get the 2 motor concept working at that voltage.

You do great work Doc and I read all your threads

Mark

 

[Doctorbass]

I wonder if the power limit of both of these motor is really the same..

let me explain: the 5302 should have a lower resistance/impedense per phase than the 5305 right?

so at 48V, it reach higher current like 80-100A so it's 5kW

the 5305 have higher resistance/impedense per phase so at 48V it reach only like 40A . but to reach 90A it need 100V (i tested that) so it's 9kW peak

to reach 9kW the 5302 would need like 140A or around this value.. this is serious current thru 12AWG teflon phase wires!

So could it be right to say that the 5305 by his lower current demand to reach high power could facilitate the high power capability?

Doc

In other words, i wonder if the max power of these two motor could not be the same

 

[markcycle]

I wonder if the power limit of both of these motor is really the same..

let me explain: the 5302 should have a lower resistance/impedense per phase than the 5305 right?

so at 48V, it reach higher current like 80-100A so it's 5kW

the 5305 have higher resistance/impedense per phase so at 48V it reach only like 40A . but to reach 90A it need 100V (i tested that) so it's 9kW peak

to reach 9kW the 5302 would need like 140A or around this value.. this is serious current thru 12AWG teflon phase wires!

So could it be right to say that the 5305 by his lower current demand to reach high power could facilitate the high power capability?

Doc

In other words, i wonder if the max power of these two motor could not be the same

What you say is true if the motors are unmodified. But with 2 wire in parallel per phase I could do 140 amps which is the same as a single wire doing 70 amps. So the 5302 and the 5305 can do the same power levels as long as the wires coming out of the motor are sized correctly.

Mark