Is there any disadvantage/issue (other than cost) in using a larger than required ESC (both brushed and brushless) ?  Say the motor calls for a 10A esc, and all you have is 30A.  Is there any reason why not to use the larger one on this motor ?

Also, if there is no reason, should one always be getting ESCs that are larger than the current needs (again assuming cost is not that different between them).

PS: A non-TX thread for a change

 I have not had any problems doing so till date   , routinely do it no issues.
I have been told that there could be issues  due to a higher auto cut off current  so chances of frying the motor are higher ,  but I reason the flip side being that  even in the case of a motor burn out control over the  model is not lost as the ESC continues current powering the receiver .So I am ok with that .

Anwar ,
If you get PM's from persons who don't agree with me please let me know and I will  

" Boy I am scared to write anything here since yesterday don't know who will start PM's to Anwar"

Anwar/Sai,

My knowledge is limited, but I thought the amp rating of an ESC is the max amp it can allow to pass through. If that be the case, will this not harm the motor? Say a motor is rated for 3-5 S, then the amp drawn at 3S level would be different than 5S level right? what happens in this case?

Pankaj

Pankaj -

Look at it this way.  How many amps are drawn depends on the motor, prop, weight of model and to a certain extend, the flying conditions (pulling veritcal, strong winds etc).  So if your motor is rated for 10A, it should pull no more than that with a proper setup.  If it draws more than that, then someone has to give in.  If the ESC is rated at 10A, then the ESC may cut the motor off, saving the day. If the ESC is rated higher, it will supply more and more current, and you end up frying the motor.  I think that is what Sai was trying to explain.

Quote from: rcforall on September 15, 2009, 07:32:02 PM
Anwar ,
If you get PM's from persons who don't agree with me please let me know and I will 

"Boy I am scared to write anything here since yesterday don't know who will start PM's to Anwar"

I am not sure if this is funny or sarcastic 

But people who used PMs felt that they had someone already voicing their opinion, and there is nothing wrong with that.

Quote from: rcforall on September 15, 2009, 07:32:02 PM

" Boy I am scared to write anything here since yesterday don't know who will start PM's to Anwar" [/b]

So don't WRITE 

well weight is one disadvantage

i would select the motor depending on the models power needs and use,once the motor is selected i will then select an ESC which is rated for motors peak current + 20% margin then the battery pack of required capacity!

note: if the motor burns won't the ESC also burnout = short b/w battery terminals = min bomb !

sahil

QuoteI have been told that there could be issues  due to a higher auto cut off current  so chances of frying the motor are higher

sai i do not understand what is higher auto cut off current

QuoteI reason the flip side being that  even in the case of a motor burn out control over the  model is not lost as the ESC continues current powering the receiver

how 

thanks

sahil

<BUMP> 

Sai ? (Since Sahil addressed the question to you directly)

QuoteBut people who used PMs felt that they had someone already voicing their opinion, and there is nothing wrong with that.

They could - and should - have re-affirmed those voicing their opinion in the forum.

If one has the courage of conviction, voice it openly.