I have 2 ESCs. One is mystery 30A and another is towerpro mag8 25A. The receiver connector of ESC have three wires brown, red and orange. I am not getting how should I connect these ECSs to receiver.
I want to know which of  these wires are corresponding to standard Futaba servo wires which are black, red and white in color..?

Please mention if your ESCs are BEC or OPTO first?

Both ESCs have BEC.

In Brown Red Orange Configuration:
Brown is -ve
Red is +ve and
Orange is Signal

In Black Red and White Configuration:
Black is -ve
Red is +ve and
White is Signal

@ vksingh: Thanks a lot...!

BTW how one could check which wire is assigned particular fuction...?
Manuals provided with ESC doesn't have any information regarding this.

Please keep the connectors of Servo or ESC as shown in Photo now the left wire is signal and the middle is +ve and the right is -ve

The pic is going to help a lot.
But is general notion black is supposed to be ground. In many of the cases the connector male and female are designed in such way that you can connect in only one way. But in this case no wire is black and you can insert the pin in both ways.
So is there any particular method to find out or check which color code will be ground etc. ..?

Sir please hold the wire as shown in the pic you should be facing the connector in such a way that the inside of the pins are visible the silver thing in the pic and the left wire is signal.

BTW the configuration is such that in any way you connect the connector the middle one is going to be positive and the there is only interchange of signal and negative wire which i hope is method of fool-proofing.

If your esc is equipped with a bec, then connect the esc to the battery and using a multimeter you can determine which wire goes where.......

@ vksingh: I got it how to make connection. Thanks again..!

I got that middle wire is positive by default. Rest of part i m not getting. Will you please elaborate in more detail ..?

The manual of ESC says that first connect ESC to receiver then switch on transmitter and then connect battery to ESC. 

that is a precaution so that the motor does not power up accidentally, if you do not connect the motor you can test your esc using the said procedure!!

See the pic

Your esc powers your receiver btw, and you do not need to connect your rx either, just connect the batt to your esc and check where, upon touching two pins, you get 5 volts!!

Got it..! Thanks.

Glad to be of some help!

Isn't there any harm if you connect it to receiver in wrong way...?

no harm just it wont work. as i said earlier it is fool proofing method that has been tried to minimize the risk. However the +ve wire was no the either side then it would have been a great risk and could destroyed any thing the receiver or ESC

Thanks a lot you guys..!
This is gonna help me a lot...!

There are some receivers (low end ones) which can be affected by reversing the connection. I remember Sai/RCForAll cautioning about one of the models.

Off the main topic but relevant here..

In the pic 'DSC04140.jpg', which is the 'Futaba connector' and which is 'JR' connector ?
I think the common name is 'J' connector. (Sometimes also 'Z' connectors may be for Airtronics)

Lot of websites say JR or Futaba connector. But I really cant find the difference in those webpages (because of small pic).
This one (DSC04140.jpg) is pretty clear.

Could someone point out what is what..

The futaba connectors that came with my futaba radio have a small protrusion that allows the connector to be plugged only one way.. While the ones I bought later which i'm guessing are JR connectors seem to have a 'D' shaped cross section so that they go in only one way.. Also futaba seem to have white-red-black wires while JR has orange-red-brown wires.. I've drawn a small paintbrush image of the bottom view of the female connectors to show you what I mean..

Oh and if you want to connect the futaba connector into the JR type socket the you have to chop off that little flange..

I am raising my question again. Is there any standard method or instrument using which we could check which pin is assigned to which parameter(apart from the method told by buzz_rc in previous post)...? Or is there any standard convention which we could follow here like the color code system in resisters...?

Identifying the -ive, +ive and signal is simple using the convention that the "darkest colored wire is -ve, the middle one is +ive, and whatever is left is signal (usually the lightest colored one)".

The bigger challenge is figuring out how they go into the receiver.  Some receivers have this clearly marked.  Others have the "Futaba slots" on one end, so you know the signal part goes there.  Some others, like the Spektrum receivers have their slots with the "D" shape of the JR connectors, so figuring out how to connect the servo/ESC wire is easy.  There are some others were you have to sort of do guesswork !

@ anwar: Got it ..! Thanks a lot..!