Motor probs - commutacar
 

Help! I just finished the brakes and was ready for the road test, when after a few 100' runs and a couple of 25' reverses, the motor began to shudder, barely moving the car, (in both forward and reverse)
I checked the high amp motor connections and found the rearmost post to be loose, and upon removing the nut, found half the bolt came with it. It appears someone had over-torqued the bolt and broken it off. It had been held into the casing nut by 2 threads, and lots of rubber cement!
Thinking I'd solved the problem, I removed the motor and took it for repairs to have a new post installed.
I got the bad news when I went to pick it up. It appears that the stator had been scraping the field coils; one of the coils had a major melt into the casing;
and two of the coil segments were slightly proud, and possibly also shorting behind the coil.
My concern is, how did this happen? The motor was very secure to the drive shaft. What I find very curious, is that there is no bearing supporting the splined end of the motor, on the housing.
It appears that all the support comes from the drive shaft. Is this correct? It's a very unconventional way to build a motor, as most motors are self supporting units via their casing bearings?
If I can find another motor, how do I prevent this from recurring, as it appears that the stator has flexed in order to touch the field coils?
Has anyone else experienced this problem?
Now, ...how do I find a replacement motor....the motor rebuilder here doesn't think General Electric will sell the field coils or any parts.
Motor tag info :
Mod 5BC 49 JB 327 C M 4000
6/ 48 123
15 Min
Wound SERIES 49 cej
AMB 40 CLASS F
Serial No CS 11

All and any help greatly appreciated. I am in Victoria British Columbia.

Take it in to your local golf cart shop and ask or look at EV Performance mostly you need to figure out what motor it is and get a new one.

The single bearing was a common way to support the armature in some golf carts. Fortunately, a new motor can be had (if the old one isn't repairable for a reasonable price) for about $350 - $400. There are various on-line sources - some quite a bit higher than others.

If you look up EZ-go, you should be able to find a few. Before ordering, make sure you take measurements of the motor shaft (diameter, spline count, length) and tell the store it is for a Spicer/Dana rear end. Will save some headache in shipping it back if some measurement is not correct.

There are two reasons I can think of that may be an issue - overspeeding and a loose field shoe.

Just noticed that this thread is in the Forum News section - probably should be moved to the Fossil Free section...

Thanks for all your help guys....I've put the motor in for repairs, I think that possible overspeed-freewheeling may have contributed to an already worn motor...
I hope to reinstall over the weekend, and will keep you posted. Tried to upload a pic of my car, but too high resolution so will reshoot pix soon...
thanks
Electrique

hi guys,
Your help has been invaluable....! Just got motorback from rebuild...looks great...except..I need you help again ASAP so I can get the motor installed this weekend....
There are two black wires coming out of the motor housing, that probably were attached to a sensor, which was missing when they took the motor apart? (it has been apart before judging by what they found inside)
I labelled one of the black wires as going to Blue/white as I disconnected everything before removing the motor.
I'm assuming it is a heat sensor to switch on the fan?
if so...what do i do now? Can you provide a schematic ( motor details listed in previous post) or hopefully tell me what type of sensor, where to get it locally, and where does it mount inside the motor?
I assume it is fairly generic and that I can pick one up at an autoparts or electronic shop. Can I run the fan continuously until I can find the sensor if thats what it is. Also if so, do I just connect the ends of the two wires together inside the motor to run the fan?
Hope this is enough information for you to help me.
Thanks again in advance....hope to post a pic as soon as possible...it's a green one like yours Ryland.

The two black wires are for the motor overtemp light (HOT light on dash). It is a normally closed switch - one wire went to frame ground, the other up to the dashboard mounted PC board for the hot circuit.

When the wire is grounded, the HOT light will light up for a few seconds (self-test) then go out. If the motor overheats (probably about 200F or so - just a guess) the switch opens and the light goes on.

On Comutacars there is a second switch that operates the motor cooling fan. This switch is mounted on the outside of the motor to one of the shoe bolts.

Sorry for the late reply - just saw your message today...

thanks for your reply...Wires have been sorted out....they didn't attach to anything! Fan had been pre-wired to run all the time, which doesn't seem a bad idea.
I'm now road-testing with some 12v batteries, to make sure all systems work before investing in the Trojan 6v - which seem to be the batteries of choice?
They are very expensive here in Canada - I'm looking at close to $2,000.00 (incl taxes) for 8 batteries! Has anyone had a good experience in buying used/rebuilt batteries?
I'm really curious as to the average top speed achieved with the Commutacar, and the maximum incline the car will climb? I'll try to repost as a new thread...but all and any comments welcomed and appreciated. Photo's soon!
thanks,
Kingsley