# "3E" Build thread.



## TheSGC (Nov 15, 2007)

That's one heck of a motor. Do you know it's max RPM? You are supposed to keep motors are high RPM, like in the 3-4K or else they will literally melt down due to the heat and the internal fan not working at low RPMs. 

My guess is that 120 volts should do it, but you would need to advance the brushes. You would want at least a 500 AMP controller, but a 750 AMP or 1000 AMP would be much better.


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## ElectriCar (Jun 15, 2008)

Where's the Bud can for size reference? Seriously, this motor is rated at 365 Amps but I'm sure will handle more for short periods like acceleration. However you can have it rewound to whatever voltage you need but the KW would be the same or maybe a tad more.

At 17.5kw on 144V you'd be rated at 122 amps and that's not very much for many vehicles. I have an S10 at 4200Lbs. It would probably need a fan to keep it cool on cruise even at full rpm on my truck. My cruise at 40-50 is around 130-140A so that would be an overload condition. Cruising at OL will burn the motor up eventually.

With a smaller more aero chassis and 12V batteries or Lithium it would probably work but still I'd want a fan probably.


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## MalcolmB (Jun 10, 2008)

ElectriCar said:


> At 17.5kw on 144V you'd be rated at 122 amps and that's not very much for many vehicles.


But if you run the motor at 144V (i.e. three times its rated voltage) doesn't it become a 52.5kW motor?

I can see you've divided the rated current by 3, but I'm not sure I understand why. I thought that current rating was limited mainly by the size of brushes and the ability of the motor to dissipate heat. In other words it's a constant for the motor. The heat generated is equal to resistance times current squared, so voltage has no effect. Or did I miss something?


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## ElectriCar (Jun 15, 2008)

MalcolmB said:


> But if you run the motor at 144V (i.e. three times its rated voltage) doesn't it become a 52.5kW motor?
> 
> I can see you've divided the rated current by 3, but I'm not sure I understand why. I thought that current rating was limited mainly by the size of brushes and the ability of the motor to dissipate heat. In other words it's a constant for the motor. The heat generated is equal to resistance times current squared, so voltage has no effect. Or did I miss something?



Watts = Volts X Amps. Rewinding it to 144V would allow much smaller wiring between the batteries for a given KW due to reduced current (amps) and more choices in controllers and auxillary equipment ie DC-DC controllers, electric heaters etc.

The math:
1KW=1000 Watts.
1000W / 144V = 6.94 amps. 
1000W / 48V = 20.83 amps (3 times as much for the same power)

When you change the voltage in the motor, the wire size is smaller as well. It may be small enough that there could end up being more room to wind it for more KW, physically possible but heat dissipation wise it may be that you can't.


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## major (Apr 4, 2008)

ElectriCar said:


> When you change the voltage in the motor, the wire size is smaller as well.


Looks like to me like the motor fixitsteve has is twice the one you have in your S10. These guys don't rewind the motor for higher voltage. They just do it. So the current ratings stay about the same when well ventilated. As long as the motor commutates o.k. and doesn't overspeed, they significantly increase power over the nameplate. Often, they will advance brushes to get down the arcing at higher voltage.

That motor fixitsteve has is a monster. Guess the real question is: What will he use for a controller?

major


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## ElectriCar (Jun 15, 2008)

major said:


> Looks like to me like the motor fixitsteve has is twice the one you have in your S10. These guys don't rewind the motor for higher voltage. They just do it. So the current ratings stay about the same when well ventilated. As long as the motor commutates o.k. and doesn't overspeed, they significantly increase power over the nameplate. Often, they will advance brushes to get down the arcing at higher voltage.
> 
> That motor fixitsteve has is a monster. Guess the real question is: What will he use for a controller?
> 
> major


I've never been one to just "do it" and hope it comes out ok. Sort of like the guy who bungy jumped a while back with some cords he made up and promptly splatted on the ground. Think about it. If you were a motor OEM and you built a motor than would handle 100kw why on earth would you label it 50KW and lose half your sales potential??? Wouldn't you want to sell as many as you could?

Sure it may be fine to overload this motor but the odds are not in it's favor. If not there's the chance for the motor being toasted. That's not something you do in the business world unless you have to and I certainly wouldn't want to roll the dice on my personal vehicle unless I was the Bill Gates type.

Motors are rated in KW which is the safe bet. While heat is what destroys motors and in an overloaded condition that's what you have, as long as it can be dissipated with a fan then yes it will handle it. Then there's the question of is the fan large enough, what happens if the fan fails? 

Heat also is wasted energy so if the motor is rated at 25Kw and you drive it a 35KW there's going to be considerable wasted energy as the windings are too small to carry the current to make that KW, thus the heat. Why would you want to waste battery power on an undersized motor? 

Heat also breaks down the insulation of the windings which eventually will cause some windings to short. It will continue to operate with the shorts but will increase overheating and hasten self destruction until there's a catastrophic short which may take out the controller as well, even if it's fused properly.

OTOH, if the motor is made by the Germans a few years back, it likely is so "overbuilt" that it can be abused and still function properly. Most American motors however can't be treated like that and live to tell about it.

As far as my post, I just laid some options on the table from my knowledge base. And I just realized that his motor is rated at 23HP while mine is rated at 19. Mine runs without a blower and doesn't get hot but it is winter right now. I also try and keep the RPM up as mine is most efficient at high RPM in addition to keeping air flow up. I'll have to keep an eye on it this summer for sure.


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## fixitsteve (May 12, 2008)

The only rpm spec I've been given is 925. I know it isn't a warp 11 or 13 but their rpm ratings are about 4000. I don't want to blow this up! I was planning on not letting it go over 2000rpms. What do you think?
12v freewheeling gives me about 1000rpms so I have to be very careful not to overrev it.
I was thinking of 72v at first to see how it worked.
I talked to kelly controllers and they recommended a dual set up, one for field one for armature syn together. 
I also have a nice blower for the motor when the time comes for it.
a few more pics


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## MalcolmB (Jun 10, 2008)

I think you're right to be cautious about over-revving such a big motor, and personally I'd keep it to 2,000–2,500 rpm for starters.

I think there's still a good argument for going to a higher voltage system, as it stretches the torque curve so that you get more torque at the top end of your chosen speed range.

If you use a 72V system, then by the time your motor reaches roughly 2000 rpm the torque will have tailed off to almost zero, so performance will be weak at the top end.

If you go for a higher voltage system, say 144V, you'll be only halfway along the torque curve when the motor reaches 2,000 rpm, so you should still have pretty impressive acceleration, especially with that motor. You still have to limit the motor speed somehow, it just gives you more useful torque at the top end and would possibly let you use a lower gear ratio and get a higher top speed. This depends a lot on how hot the motor gets though.


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## ElectriCar (Jun 15, 2008)

MalcolmB said:


> I think you're right to be cautious about over-revving such a big motor, and personally I'd keep it to 2,000–2,500 rpm for starters...


Just curious, how do you arrive at this number as being safe if the design speed is 925? 2500 is 270% of design speed!


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## MalcolmB (Jun 10, 2008)

ElectriCar said:


> Just curious, how do you arrive at this number as being safe if the design speed is 925? 2500 is 270% of design speed!


I didn't say it was safe, I said it's the limit I would personally use. I assume that since this is a DIY forum we take responsibility for our own tinkering 
The number is a guesstimate based on the fact this is a GE motor, which seem to be well built and widely used in conversions, and the fact that similarly sized Warp motors can be run up to 4000 rpm.

From what I've gathered most series motors are also at their most efficient at around 2,000–3,000 rpm. I'm not sure if this also applies to a monster like this, so if anyone knows otherwise please shout!

It's taken me a while to learn that the numbers on a series motor rating plate are just one point in the performance envelope of a motor. They don't usually define the limits of the motor.


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## major (Apr 4, 2008)

ElectriCar said:


> I've never been one to just "do it"


Maybe not. But that is what ADC did with that motor in your truck. It is basically the same design (winding) as its original application, a 48 volt, 10 HP forklift motor. Yeah, maybe they advance the brushes and test it at the higher voltage, and hope for 2000 hour life whereas the original application needed 20,000 hours. But that is what you're driving. And it's working pretty well, right?

Regards,

major


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## major (Apr 4, 2008)

fixitsteve said:


> I talked to kelly controllers and they recommended a dual set up, one for field one for armature syn together.


Hi steve,

Kelly is nuts.

While you have that armature sitting there, please count the bars (number of commutator segments) and post it. Also, some close-ups of it showing how the armature coil (the copper bar running thru the steel core) looks with both ends in the picture.

Regards,

major

ps....Please measure the core (steel part of the armature), diameter and length.


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## ElectriCar (Jun 15, 2008)

MalcolmB said:


> I didn't say it was safe, I said it's the limit I would personally use. I assume that since this is a DIY forum we take responsibility for our own tinkering
> The number is a guesstimate based on the fact this is a GE motor, which seem to be well built and widely used in conversions, and the fact that similarly sized Warp motors can be run up to 4000 rpm.
> 
> From what I've gathered most series motors are also at their most efficient at around 2,000–3,000 rpm. I'm not sure if this also applies to a monster like this, so if anyone knows otherwise please shout!
> ...


The design speed of a motor takes into consideration what type of banding holds the armature together. If it's plastic banding it's going to be rated at a lower speed (925?) than if it's steel banding (4000?). 

As before when discussing amperage capacity, I wouldn't think a company would limit its' sales potential by placing a very limiting rpm rating on their motor. I know there's a safety margin built in but how much? I would imagine though a motor would withstand a 50% overspeed by design for a safety cushion, maybe even double but I personally wouldn't recommend someone invest the time and money in a project of this magnitude and gamble the motor will stay together, only to it fly apart while going down the road one day.


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## major (Apr 4, 2008)

ElectriCar said:


> this motor is rated at 365 Amps <snip> My cruise at 40-50 is around 130-140A.


Hi ElectriCar,

I've been looking over your posts and at evalbum of your S10. Nice to see someone using an EV and posting some real data. I am going to post a few comments.

You use the ADC FB1 9 inch motor with a 144 volt battery. But you said your motor had a rating of 19 hp. evparts.com rates that motor at 1 hour, 30.4 hp at 144 volts.

You say you think you'll get about 500 whr/mile, without lights and heater. At 45 mph, that is 22.5 kW. But 135 amps from a 144 volt battery is 19.4 kW. Not all that far off. 

So assuming 75% efficiency from battery to motor shaft, that would be about 23 hp to 20 hp. Under the 144 volt rating for this motor. However, you're not running 144 volts on the motor, are you? 144 V and 20 hp would mean the motor RPM would be up near 7000 RPM. I don't think that is the case, so you obviously select a higher gear. This allows a lower RPM for the same power by reducing the motor voltage. And that increases motor current. The curves from the web site show that power at 96 V on the motor occurring at about 3300 RPM. And that would be about the rating of the motor at that motor voltage. You're probably somewhere higher than that with your actual gear ratio, hopefully not lower, as then you'll be exceeding the motor rating.

Concerning fixitsteve's motor. You got the 365 amp rating by dividing the 17.5 kW rating by 48 V, right? But it says output. So, it would be actually be higher, maybe like 450 amps. And, the 925 RPM speed is most likely the RPM at rated power, 17.5 kW, or 23 hp. That equates to 130 lb.ft. It is a monster. But back to my point. 925 is RPM at rating. Not a maximum RPM. All series motors can be expected to operate above the RPM at rated power. I would be surprised if 2000 RPM or higher wasn't common in the original design application for this monster.

Like I said before, this thing is twice the motor you have in the S10. If fixitsteve can find a monster controller for it, it could drive your truck while towing another one behind, both loaded with batteries (cause you'd need them). 


Regards,

major


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## ElectriCar (Jun 15, 2008)

major said:


> Hi ElectriCar,
> 
> I've been looking over your posts and at evalbum of your S10. Nice to see someone using an EV and posting some real data. I am going to post a few comments.
> 
> ...


Not sure where you're going with some of the info above but I still wouldn't over rev this motor to anywhere near 2-3000 rpm. It isn't designed for that. If it flies apart fixitsteve is going to be pissed at having to put humpty dumpty back together again after doing all that work! Here's some info about series motors design and use. 

Don't know if you are aware but there's a guy here who's already shredded one motor by over revving it, judebert, and I'm sure he wasn't very excited about it. 

Besides, why would he need to run this motor that fast? At high rpm series motors have very little torque. Mine is pathetic at high rpm but it is VERY energy efficient and the speeds I operate at are in it's design parameters. 

*Fixitsteve, I suggest you contact the traction motor department of GE and ask for technical support. *I did that with my motor on questions I had about operating voltages over 144V. They should be able to give you more concrete data and get you off on the right track and away from any conjecture. Then you will be confident in your decisions about what you can do in operating this motor without risking catastrophic failure!

And I hope you get it all worked out without ripping stuff up with this 13" behemoth!


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## fixitsteve (May 12, 2008)

major said:


> Hi steve,
> 
> Kelly is nuts.
> 
> ...


Thanks for everybodys input!
Major hope this is what you asked for, the motor is back together and hard to measure.
Comm bars 29
Output shaft dia 1.625" shaft is thicker inside motor
Shaft length about 30"
some more pics, Steve


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## fixitsteve (May 12, 2008)

And I hope you get it all worked out without ripping stuff up with this 13" behemoth![/quote]


Thats why I am asking! 
144v would be neat but I don't want to blow it up and if my math is right that would put the torque at over 700lbft. Even if I keep the rpms down the trans, driveshaft, cv joints, axles, and my drivers license wouldn't last very long. Steve


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## major (Apr 4, 2008)

ElectriCar said:


> Besides, why would he need to run this motor that fast? At high rpm series motors have very little torque.


Hi ElectriCar,

The 144 V curve shows over 100 lb.ft. at 3000 RPM for your S10 motor.

And, I didn't get the pics I wanted from fixitsteve, but it does look like the monster GE has steel banding on the armature. Which is pretty much standard construction for GE motors of this size. It would be nice to an answer from GE regarding RPM limits, but I doubt they will talk to him. Maybe, doesn't hurt to try.

Why run the motor at high RPM? More power.

And fixit, nice paint job on the monster

Regards,

major


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## major (Apr 4, 2008)

fixitsteve said:


> 144v would be neat but I don't want to blow it up and if my math is right that would put the torque at over 700ftlbs. Steve


Hey Steve,

Let's take a look at your math. Even with a 2000 amp controller, you'll not get 700 lb.ft. out of the motor. Maybe close to 600. But that does require a 2000 amp controller and battery. Got those?

major


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## fixitsteve (May 12, 2008)

While I continue to research controller options the fun continues. When I started this project my first goal was to make the ev move under it's own power as soon as possible. I am doing this conversion at work and it will make it easier if I don't have to push it in and out all the time. Made lots of progress this weekend. Motor in and mounts roughed in. Steve


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## fixitsteve (May 12, 2008)

Some more progress. Motor mount done. Hooked up 1 battery thru solenoid so I can move car in and out easier.


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## fixitsteve (May 12, 2008)

More progress. Hooked up an old engine analyzer I had from years ago. I can watch volts up to 100V, amps to 1000, temp, RPM with magnetic sensor on front of motor. I will leave this on the passenger seat while I sort out how everything works. Built a vacuum pump for the brake booster. Used a door lock/door closer vacuum pump from an old Mercedes 140 body. Also a vacuum reservoir from pvc pipe.


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## fixitsteve (May 12, 2008)

Not much done on the conversion but I got some things fixed on the car. Drivers door lock fixed, power locks working, power windows working, repaired shift linkage. I found a 89 325e at the local u-pull and save junk yard and got some trim pieces and blower motor I needed. Found this 4/0 wire at the metal recyclers, only paid $40 for 30 feet. It is stiff but I will only have to bend it once when I hook everything up. Anybody know how many amps 4/0 wire will carry? Hopefully the 2000 amps I will someday need! Have driven the car a couple times now but only about 10mph, not enough for the EV grin but still neat!


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## etischer (Jun 16, 2008)

I'm using 4/0 wire too, it is rated 380 Amps. Of course there is a lot of thermal mass there to heat up, so I'm sure you can exceed the max rating for a short time. I think the table I used assumes 90 deg C rated insulation. I bought high flex 4/0 cable on ebay, it was $2.5/ft.

http://cgi.ebay.com/50-4-0-WELDING-...ryZ11774QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Crimp ends are the expensive part, I think I paid about 8 bucks per lug. I spent 200 bucks on cable, and $450 on crimp lugs. 










You gotta get/rent one of these













fixitsteve said:


> Not much done on the conversion but I got some things fixed on the car. Drivers door lock fixed, power locks working, power windows working, repaired shift linkage. I found a 89 325e at the local u-pull and save junk yard and got some trim pieces and blower motor I needed. Found this 4/0 wire at the metal recyclers, only paid $40 for 30 feet. It is stiff but I will only have to bend it once when I hook everything up. Anybody know how many amps 4/0 wire will carry? Hopefully the 2000 amps I will someday need! Have driven the car a couple times now but only about 10mph, not enough for the EV grin but still neat!


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## fixitsteve (May 12, 2008)

Worked on 3E for a couple of hours on sat. Fuel tank and lines out. Fuel tank is under back seat and there looks like enough room for some batteries there. Cleaned out trunk and made some measurements for battery box. The speedo was inop and when I took the instrument cluster appart someone had been in there before and I could not save speedo. Bought a used inst cluster and now speedo works. Installed 12V gauge in place of fuel gauge to watch that system. I am planning on a cycle analyst to watch high voltage system. later, Steve


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## dtbaker (Jan 5, 2008)

etischer said:


> I'm using 4/0 wire too, it is rated 380 Amps.
> Crimp ends are the expensive part, I think I paid about 8 bucks per lug.


yikes....
most people I think end up using 2/0 welding cable. Fine strand, bends easy, carrys lots of amps. Sounds like you paid way too much for lugs though.


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## Dennis (Feb 25, 2008)

You do realize I hope, Electricar, that higher voltage ran to a low voltage rated DC motor does not mean it would over heat it. For the same full load HP rating the higher voltage will allow the motor to run cooler actually since the current required for same HP will be less and the motor will be turning at a higher RPM so more air flow from the fan will also cool it. However, if the person doing the conversion does not change the gear ratios for the new voltage then indeed more current will flow through the motor windings than at the original value from the lower voltage and thus will necessitate a voltage change by re-winding the motor with more turns of smaller fine wire, but also realize that the HP rating is also going above the full load rating when the gear ratio was not changed for the higher voltage. So as long as gear ratios are changed then heat issues from higher voltage is not an issue..


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## Georgia Tech (Dec 5, 2008)

Man I don't know How I missed this thread months ago. There is one of thes motors for sale right down the road that I have been considering for an F-250 for over a year now. it is only 250 bucks!!! 
I have been looking for information on here long and HARD for this motor.

I almost certain this motor will turn 3 to maybe 4 grand. The issue I have and keep asking on this forum is with only 29 com bars can I run the thing at 144 Volts?

Also about the Data plate? Got to know how to use this data in your application. Read the data plate carefully it says 467 amps for an hour!! That is Steller!!!! From there, understanding of motor design will help you decide how you can push it in an EV.


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## Georgia Tech (Dec 5, 2008)

fixitsteve,

I am EXCITED to know how our project is going...I have been looking at this EXACT motor for over a YEAR and a HALF NOW!!!!! 
Where are you on your project?


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## DONEAL (Sep 10, 2008)

fixitsteve,

That wire looks like 4/0 thhn? I could have got some out of our scrap bin at work but read on this forum, that it was recommended against it. I purchased the 2/0 “welder leads” type. Has smaller strands.
And I think you can get larger wire maybe 4/0 weld leads? not sure.
From past experiences of the positive battery lead (on old ICE) breaking within the insulation not visible from the outside. I decided to go with the more flexible wire. That is one monster of a motor!


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## Georgia Tech (Dec 5, 2008)

What's the latest on this project? Got it on the roaad yet?


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## fixitsteve (May 12, 2008)

FOR SALE

As much as I hate to do it, my toy is for sale. Things changed from bad to worse and can no longer work on it. It moves under its own power, but needs a proper controller and batteries. $5000 or best offer. later, Steve


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## Georgia Tech (Dec 5, 2008)

fixitsteve said:


> FOR SALE
> 
> As much as I hate to do it, my toy is for sale. Things changed from bad to worse and can no longer work on it. It moves under its own power, but needs a proper controller and batteries. $5000 or best offer. later, Steve


breaks my hear to pieces...I really wanted to know if this motor could handle 144 volts..


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## fixitsteve (May 12, 2008)

Still for sale. Somebody make me an offer. Need the room in my garage. Whole car or just motor. Steve


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## GE11 (Oct 24, 2011)

Steve did you ever sale this thing?

What Transmision did you use for this?


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## fixitsteve (May 12, 2008)

Still for sale!
Man. trans. from car. Look at pics in build thread and you can see it attached to motor being installed.


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