ESC question...

[neavissa]

Hi there,

I just played around with the r/c calculator over at the dark horse rc website and noticed that the average amp draw of a Logo 800 is 33amps?! Why would you need a 160amp esc then?!

thanks,

G

[rcmarty]

The peak draws under heavy loads is going to be your requirement.

33 amps x 58 volts = 1914 watts / 746 (1 hp) = 2.56 hp

2.5 hp isn't going to do much for a big heli like that.

I'm guessing 5-7 hp is about right ( ~ 4-5000 w)

esc rated for 12.43 hp ( 9280w ) so there's some safety room in there

Martin

[Jays200]

I've had a peak of 195A on my Kosmik logger.

With a flat pack at 51.8 volts that's 10101W peak
With a full pack at 58.8 volts that's 11466W peak

I'm a firm believer in lots of headroom in the ESC amps department.

My Logo 400 has a 80+HV with 6S
My Logo 800 has a 200A Kosmik on 14S
and I just bought a Helijive 120 for my new 600SX on 12S

Yeah it could be overkill or just cheap insurance. I've made my mind up. Know it's your turn.

[neavissa]

Thanks for all the replies! I guess I looked at ESC like I look at a balcony. It is designed to hold 100 people, even though it would never fit more than 30 people! I thought that when an ESC says 80amps, that it withstand that kind of current all the time and that it can easily peak 3 times that much... but I guess its the other way around! No more than 80amps, peak or not, when it says 80, right?!

thanks,
G

[rcmarty]

My understanding is that a 90a esc is designed to handle 80a all the time.

I know kontronics jive esc will take " much more " with the optional heatsink, according to the manual.

Of course other brands have different level of 'more'

Jays theory is a solid one. No one ever dropped out of the sky from having an esc that was rated to high. Jamming a 120hv with heatsink under a logo 500 lid will be tough but electrically your good to go. ( i tried and gave up .. lol)

Martin

[neavissa]

Originally Posted by rcmarty

My understanding is that a 90a esc is designed to handle 80a all the time.

I know kontronics jive esc will take " much more " with the optional heatsink, according to the manual.

Of course other brands have different level of 'more'

Jays theory is a solid one. No one ever dropped out of the sky from having an esc that was rated to high. Jamming a 120hv with heatsink under a logo 500 lid will be tough but electrically your good to go. ( i tried and gave up .. lol)

Martin

Thinks must have changed or must remember it wrong?! It used to be a not too good of an idea, to put a way bigger ESC in your application, than needed. At least when it came to cars?! People kept burning up esc's and I kept wondering why not use one that is rated way higher than needed?! The explanation was something like putting a Bugatti motor into a SMART car...

G