Help connecting battery to esc to motor - RC Groups
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Feb 11, 2010, 03:06 PM

Help connecting battery to esc to motor

HI, fellow rc flyers, i'm a newbie. to electric flying and building my first foamie. p51 d Mustang (what else...). i have a eflight Park 480 Brushless outrunner motor 910 Kv, an Emax esc-35A and a Eflight 2100mAh Li.Po battery.
Problem: please advise how to connect them all up so that they may eventually work in harmony. what confuses me is, there are 3 x wires from the motor colours black blue and red. on the Emax Esc. there are 5 wires and a a small plug with 4thin wires. on one side of the ESC are 3 blue coloured wires and on the other end a red and black + the small plug with thin wires. (no problem to connect that side )
Question how does one connect the 3 blue coloured wires on the ESC to the Black, blue and red wires on the outrunner motor without knowing which colour wire on the motor connects to which blue wire on the ESC of the three there.
Kind of silly to put all three wires out as blue.. or am i missing some thing here.

have search the net for answers but nada.. so i apeal to you please help me understand .

ps there are no explanation on the user instruction page supplied with the ESC only a diagram. with no clear instruction what goes where between motor and ESC.
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Feb 11, 2010, 03:53 PM
Surface, Air & Water Rc Toys..
freechip's Avatar
The reason why your motor wires are colored that way is so they match up with e-flites ESC as this is a E-flite motor.

But in brushless it does not matter what color goes with what so thats why your ESC are all blue and some are all black and other color codes simply to match with their own brand motors.

With brushless ESC and motor simply plug all 3 wires in any order and carefully test the motor and see if it spin in the correct direction you need it to.

If it does not spin in the direction you want then you simply swap 2 of the 3 wires and ONLY 2.

On the other side of the ESC the RED & BLACK wire are of course the main battery leads that you need to solder the male end of the connectors you are using on your batterys.

The other small 3wire lead is the ESC lead you need to plug into the throttle channel of your RX.
Feb 11, 2010, 03:57 PM
Registered User
ebill3's Avatar
Originally Posted by Fox-2
Question how does one connect the 3 blue coloured wires on the ESC to the Black, blue and red wires on the outrunner motor without knowing which colour wire on the motor connects to which blue wire on the ESC of the three there.
Doesn't matter. Just connect the three blue wires to the three motor wires. If the motor rotates in the wrong direction, just switch any two motor to ESC wires.

Feb 14, 2010, 06:56 AM

Help connecting battery to esc to motor

Ok Guys, Many thanks for the responses, everything done as you suggested connecting the O/R. motor to the ESC and the battery. Some more help needed, once more please.

1. How is the receiver connected to the Li Po battery for supply? do i need a UBEC in between, as i read from another thread. The battery is a E-Flight 2100mA/h (3 cell.) and the receiver is a JR - RS77S. i have read up what a ubec is for. i guess i just need confirmation that i'm on the right track

2. I connected the motor to the ESC. and plugged the Battery in and the ESC beeped continuously, (more then 20 times).I disconnected the battery, for fear of damaging anything. The little plug from the ESC was plugged into the trottle position on the receiver only.

Thankyou for you advice
Feb 14, 2010, 10:13 AM
Registered User
1. Your EMax ESC should have an internal BEC which supplies power to the receiver and servos. You don't need a UBEC as well.

2. The connections sound o.k. The most likely problems are:
- transmitter not switched on
- throttle not at zero
- throttle needs to be reversed (usually that's for Futaba transmitters)
- battery not fully charged

Feb 14, 2010, 11:53 AM
Registered User
ebill3's Avatar
One more thing to check---

The connector from the ESC to the throttle channel of the receiver could be reversed - plugged in backwards.
Feb 15, 2010, 07:03 AM
Once again thanks for your advice. will have to tend to the problem once back on dry land. I,m currently at sea and will return to sort out the problem. ..for now cant wait to get that mustang in the air. Well, i guess one month is not too far to go. cheers till then, will keep browsing this forum on occasions.
Feb 15, 2010, 08:24 AM
jackerbes's Avatar
Here is a diagram of it all hooked up with an external BEC in use also:

The UBEC is normally used when you are using 4S or higher cell counts. And when you use the UBEC (marked as the BEC in the diagram above) it is normal to disconnect the red power lead from the ESC's BEC power and throttle signal lead so that there is only one 5V power source at the receiver.

The reason for using a UBEC with 4S and higher is that many ESCs have a linear power supply for their BEC output voltage and that turns the excess voltage into heat. The higher the battery voltage the more heat it generates and having more than a 3S (12.6V) input voltage can generate more heat than the ESC can handle.

Some newer ESCs have switching power supplies for the BEC output (and most UBECs also have switching power supplies) and those will handle the extra voltage without generating excess heat.

You would normally put the BEC voltage into the receiver on the throttle channel along with the throttle signal. The three wires in the BEC connector are ground, +5V, signal and the +5V is on the red center wire.

If you use the UBEC the throttle signal needs to still be supplied and the ground connected but the red (+5V) lead is normally removed from the connector.

The UBEC can be connected to the BATT channel if there is one, any unused channel, or to a "Y" cable on any channel because the 5V buss is common to all channels.

Aug 14, 2015, 12:46 AM
Registered User

issue with setup?

Just got a fs-th9x transmitter to begin programming and building a foam fleet.

After getting all servos aligned and made sure they would port easily I checked the last thing.... The ESC plug going to the rx....

The plug is a different setup. I needed a high discharge for the motor and servos.

Any ideas on what to do to fix?
Aug 14, 2015, 01:51 AM
Bombs away! Err...landing
Ira NZ's Avatar
Originally Posted by jeter.kurtis
Any ideas on what to do to fix?
To fix? I don't see anything broken.

Looks like your battery has XT-60s, so put a male XT-60 on the ESC and bullets on the ESC and motor.
Aug 14, 2015, 10:17 AM
Registered User
I got the xt 60 and bullet adapters along with more servos coming.

From what I see the battery reciever plug doesnt fit onto the Rx.

There is no way for the receiver to be powered up for communication.

Sorry if the answer is right in front of me. I have been only used rtf, bnf kits just started completely scratch building. Still needed a different motor, and power setup.
Last edited by jeter.kurtis; Aug 14, 2015 at 10:37 AM.
Aug 14, 2015, 10:36 AM
jackerbes's Avatar
The RX is connected to the ESC's throttle/BEC (Battery Eliminator Connector) lead. That is the three conductor cable that has a servo type connector on it. And that throttle/BEC lead supplies power to the RX and all the servos connected to the RX.

The battery will burn up the RX if it is connected directly to it. The battery is 12.4V or so, the receiver can only handle 5-6V or so.

The connector in you image, if it is attached to the battery, is the charging/balancing lead. It allow foer access to each of the cells in the pack for those purposes and also to allow you to check the voltages on each cell in the pack. There are four sockets on the thing in your hand so you have a 3S battery.

This page explains the wiring and connections on a battery pack:

Choose 3S and turn on the balancer wiring hookup to see your pack.

Aug 14, 2015, 02:36 PM
Registered User
So, would these pics attached be the correct setup?( beside the xt60 plugs/adapters I am still waiting on

If not what am I missing ?

Plugs from the motor > ESC > receiver.
Only issue is the battery connecting to the receiver.

3s pack will connect to the ESC but not the receiver. So do I need to just get a 2s and try for same results?
Last edited by jeter.kurtis; Aug 14, 2015 at 03:07 PM.
Aug 14, 2015, 03:33 PM
Registered User
A thread I ran into while confusing myself more.

Also does the balance connector on battery need to hook to Rx
Aug 14, 2015, 03:56 PM
Registered User
If the ESC has a BEC (as most small ESCs do), then that will supply power to the receiver via the throttle channel plug.

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