ESC Backup In Case of ESC Failure???

[pvolcko]

This is necessary for the reasons you stated in an earlier post on this thread, correct?

Yes. It prevents a floating reference voltage between the ESC and rest of the electronics, which can lead to undesired current flows and other problems.

What about the throttle lead from the ESC?

For CC Edge HV ESCs there is no internal BEC and no need to worry about that positive pin on throttle connection.

The western robotics instructions are safe from their perspective. Regardless if the ESC has an internal BEC or not, it is always safe to pull the positive pin from the throttle servo, when using an external BEC or Rx Pack. But it isn't strictly necessary when there is no internal BEC.

 

[HeliDinoRC]

That makes sense....Thanks, Paul. It's the ole CYA. I'm all to familiar with that!

 

[HeliDinoRC]

As promised:

View attachment 10439

I have decided on option 1 and use the BEC. I will probably go with your suggestion and put a plug inline for the BEC so I can power it with a 2s battery for testing, etc.

Is it advised to use a harness between the 12s batteries and the ESC/BEC Plug connection or just wire it exactly like your diagram?

 

[pvolcko]

Matter of preference. Harness/adapter route takes an extra connector, which is one more opportunity for a bad solder joint to foul things up, IMO. On the other hand, people like them because you can opt (another option!!!) to run the BEC off main batteries without having to plug in the ESC connection, when on the bench. And I supposed in the event of an ESC fire or other catastrophic problem it is easier to karate chop the adapter/harness and hope it unplugs both main batteries from the ESC than having to unplug both batteries individually.

I've never done it myself. One too many connectors for my liking.

 

[HeliDinoRC]

So without using a harness you have two points of connection with the ESC. Which battery should be pluged in first or does it matter?

 

[pvolcko]

It shouldn't matter, but negative pack first I'd say if you're paying attention (bottom of the two main packs in the diagram).

 

[HeliDinoRC]

Thanks, Paul!

 

[xokia]

I'm starting to think people don't understand what a BEC is (Battery Elimination Circuit) it was intended to run off the main packs and eliminate the need for a separate RX pack. Makes no sense to have a BEC and a separate RX battery IMO.

I'll run a BEC on helis up to 6S-8S but on 12S setup I just use a separate 2S RX battery it makes more sense and can handle the load demands of the HV servos.

 

[murankar]

The reason I chose a beck was to hive me more head room on the amps and to provide a 6v current to my system. Since I do not run hv this was the best option for me.

With bigger helis it's better to separate the rx, servos and fbl from the motor. Imo.

Sent from my LG-E980 using Forum Runner

 

[pvolcko]

lol... the auto corrections are hysterical.

 

[murankar]

Attacked again. Darn it.

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[xokia]

The reason I chose a beck was to hive me more head room on the amps and to provide a 6v current to my system. Since I do not run hv this was the best option for

So run a LifePo pack instead of a Lipo. Delivers 6.0V and gets rid of all the extra points of failure. Although if you choose a good BEC you shouldn't have to worry about overcurrent

If you are scared to run just a BEC then just run a straight RX pack. It doesn't make sense to mix and match IMO

 

[murankar]

Makes no sense on a 450. Even a separate bec is over kill. My only reasons were for and extra amp or 2 and the extra 1.? Volts.

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[coolgabsi]

I use it on my warp. It's needed but that's because my servos draw more than my esc's internal bec can supply at high loads.

If I had an option not to, I would totally not

On bigger birds, there is a lot more on steak. Lol I definitely run one on my bigger ones

 

[pvolcko]

Just ran across something of relevance here:

Note: Please be aware that the SC-BUG is NOT designed to work with HV (High Voltage) setups using high power servos. Due to the very high amperage draw of these systems, we recommend the SC-BUG for 600 class helicopters and smaller, utilizing a BEC.

Got this off helidirect's page for the backup guard. So if you're running HV servos or servos that draw a lot of current, then using the backup guard is not recommended. In such a case you either need to trust in your BEC or run a separate 2S Rx pack.

 

[HeliDinoRC]

Hmmm....Noted! Thanks for finding that. Anybody looking for a NIB SC-BUG??? LOL!

I'm starting to think people don't understand what a BEC is (Battery Elimination Circuit) it was intended to run off the main packs and eliminate the need for a separate RX pack. Makes no sense to have a BEC and a separate RX battery IMO.

I'll run a BEC on helis up to 6S-8S but on 12S setup I just use a separate 2S RX battery it makes more sense and can handle the load demands of the HV servos.

I chose the BEC route on my G630 in an effort to save grams, I don't have another battery to care for or charge/forget to charge, and I can have a constant current running to the servos. I may not notice the voltage drop as a Rx battery drains, especially flying sport, but in my mind I want a constant current to the controls. I chose the WR Hercules BEC because it has a high input voltage rating of 60V and can handle 15 amps continuous and 20 amps peak. I thought that this would handle anything I could throw at it with a low risk of failure and I would have the headroom to push it if I wanted to. Also, the WR has a power bus and allows for direct connection of the servos to the BEC. In my mind, this provides for optimal power to the servos with minimal servo connections. The FBL is powered by a direct connection to the BEC as well. In addition, I don't have to run HV through the FBL.

I have HV servos (rated at 6.0-8.2V) and though I would run them in the middle at 7.4V and the WR BEC allows for easy switching. I also have the option of running 5.2V, 6.0V, or 8.2V through easy dip switches located on the unit. My only concern is mounting the BEC underneath the frame but it needs to be in a well ventilated area. In a belly crash that will be the second thing to hit the dirt after the landing gear breaks.