RC India

hi every one
i have got a problem
last time i crashed my plane.after that inscident i tried to test my motor weather its working or not ,it worked finely.but the next time when i tried to run it the wires from the battery to the esc  got heated up ,even there was no  short circuit outside.i removed the battery immediately.again i tried the same thing happened.when i tried the third time all things are working perfectly but motor is not roraring and the sounds those used to come from the esc are not coming.is the motor winding short circuit or esc got burned??? :headscratch:coz i can still power up my reciever using that esc.i tried to check weather motor is short circuited or not but resistance in my multimeter shows1 for all the three wires.plz  need help from all of you.
now another question is that should i buy another (motor and esc) or buy only esc.
plz help :help:

Check another motor in your ESC.

problem is that i v got only one brushless motor with me .

if your esc is not powering the receiver than the problem should be in your esc.. i think your esc is not working...
(if you have multimeter than you can figure out problem) to check your motor weather it is in working condition or not.. try to check the continuity of motor with multimeter. or resistance if it is showing 5ohm to 10 or more than your motor is perfect but if resistance is 0 than there is problem with your motor..

Digital multimeter ?
In which resistance range did you checked the motor ?
A digital multimeter reading 1 indicates, value is out of range, so if it shows 1 b/w two motor terminals, it means open circuit.

Check resistance b/w your motor leads with lowest resistance range in your multimeter - the reading should be a few ohms.

i had  set the ohm range to 200 ohm.

yes digital multimeter... mine multimeter is auto ranging multimeter so i don't have to set range.. just select resistance and check between first A and B wire ,B and C wire ,C and A wire. the resistance of all terminals are almost same...no big difference.

i connected one probe of digital multimeter to the body of the motor and another to each lead one by one .but in all three cases the reading was 1

the body of motor should be not connected state, check between wires as specified by gunnu sir

i once  again tried to take the reading according to gunnu sir and got all the readings constant.

i just check resistance of my 4500KV motor and it shows A. .7ohms B .6ohms C .7ohms.....

so if your multimeter is showing 1ohm then your motor is good...

:banghead:  , I meant to check resistance b/w motor terminals,.
btw, yeah if there is no any short circuit to motor body, the reading should be one at left most side of your multimeter screen, isn't it ?

can u specify the motor model and whats the readings you got?

What constant value ?  , also which is your motor ?

thats fine.. and make sure only tips of your meter probes touching wires not fingers coz your body resistance may also effect

yes while i tried to check weather motor coil was shorted to the body or nt  igot reading 1.
and after follwing instructions from gunnusir i just checked the resistances between any two terminals ,which was 1.6 for A-B=B-C=C-A

Your motor is perfect then :)

Now time to check ESC, Which is your ESC ?

I get 84Kohm reading b/w all 3 of my 30A ESC terminals, so The reading should be in Kohm range, check it out :)

my motor is turnigy aerodrive 1000kv motor.i was using 18amp imax budget esc. and the constant value means the resistances betn any two terminals of the motor which i found to be same for all the three combination of terminals and was found to be 1.6 ohm

That is fine, and your motor should be good, check ESC as I said above (resistance b/w all terminals might be in Kilo ohms range)

frnds plz don't call me sir and @sooraj if your esc is burnt you still get reading while checking it.. coz this was happened to be.. once i connect my esc in wrong polarity and it burnt but when i check resistance it still shows .. so the only way to check esc is weather to connect it with other motor or check it with oscilloscope...

My ESC is not burned :) , it is in perfect condition.

@Rajesh, Unrwrap that heat shrink arout your ESC, and look for any visible damage to any of the FETs .

i just checked the esc terminals
got this
A-B=6.22Kohm
A-C=6.22kohm
B-C=0.1kohm
does this imply that esc is burned or damaged
 if yes then why am i still be able to use that esc to power up my reciever.

Well, it seems one pole of your ESC is damaged. - Just look in by unwrapping those heat shrink around your ESC - look for visible burned FETs.

Also , the BEC section is separate in an ESC, so if it is working fine you can use the ESC as a BEC only.

your esc generally convert direct current to alternating current with variable frequency which control your motor speed.. so there are two circuits in your esc one direct current and other alternating current circuit... which has MOSFET (Metal Oxide Semiconductor Field Effect Transistor) which separate both circuits (i think) so we cannot check esc  with multimeter...

Up to that part you are correct. But all those FETs are not used there to separate the DC  part (BEC and battery I/P) with AC parts (Motor drive part - Electronically commuted) .

The FETs are used to provide the sufficient current to motor.
The BEC part consist of a simple linear voltage regulator , so damage to the motor drive section or microcontroller etc... won't affect the BEC.

EDIT :
And we can check ESC with multimeter, or any electronic devices are preliminarily checked with a multimeter :)

still you can use multimeter to check the FETs in ESC are dead or not

but be cautious dont connect motor and disconnect battery if anything unusual.

put multimeter to ac 20V or greater voltage checking mode

with connected receiver throttle channel and battery,

give a 30% throttle and check output of esc A-B, B-C, C-A.

Post results.

EDIT: Never short between ESCs output terminal while puwer up , that should kill your ESC

@sooraj thats why i write (i think) there in last line

@Rajesh14305 , If you are familiar with electronics and soldering, try opening ESC and replacing the damaged parts (Only if economically viable) .
Otherwise you can use this as just a BEC, and buy another ESC for your motor :)

checked the voltage ac betn two terminals out of three setting range of multimeter 200 and got followings
A-B=0 at 30%thro
B-C=0 at  30% thro
A-C=23.5 at 30% throttle

That means your FETs in channel B is damaged.
something wrong with your reading too, how much volts are you supplying to the ESC?