Notices
Brushed/Brushless motors, speed controls, gear drives Discuss all aspects of brushless motors, brushed motors, speed controls (ESC's), gear drives and propellers in this forum.

esc amperage

Old 09-12-2022, 04:35 PM
  #1  
[email protected]
Junior Member
Thread Starter
 
Join Date: Nov 2021
Posts: 4
Likes: 0
Received 1 Like on 1 Post
Default esc amperage

if a motor suggests a 70~80 amp esc, can I use a 60amp?
Old 09-13-2022, 12:31 AM
  #2  
Cecil Webb
Junior Member
 
Cecil Webb's Avatar
 
Join Date: Sep 2022
Location: United States
Posts: 11
Received 1 Like on 1 Post
Default

No. You should not use it. If so, it will burn up the ESC.
Usually you should use ESC equivalent or greater than motor requirements.
Old 09-15-2022, 12:46 AM
  #3  
ron_van_sommeren
 
ron_van_sommeren's Avatar
 
Join Date: Sep 2002
Location: Nijmegen / Nederland
Posts: 591
Likes: 0
Received 15 Likes on 12 Posts
Default

Originally Posted by [email protected] View Post
if a motor suggests a 70~80 amp ...
Isn't that just he motor's maximum current rating? Or specifically an ESC rating advice?

Note that motors can handle any voltage, as long as rpm, actual current and actual power don't get too high.
The winding wire insulation/lacquer/resin can handle several hundred volt.

Originally Posted by [email protected] View Post
... can I use a 60amp?
Yes. But only if you prop-load and voltage the motor to draw that current at wide open throttle (WOT).
Current drawn is proportional to pitch, voltage² Name:  eek.gif
Views: 28
Size:  1.0 KBName:  eek.gif
Views: 28
Size:  1.0 KB Kv³ Name:  eek.gif
Views: 28
Size:  1.0 KBName:  eek.gif
Views: 28
Size:  1.0 KBName:  eek.gif
Views: 28
Size:  1.0 KB and prop-diameter⁴ Name:  eek.gif
Views: 28
Size:  1.0 KBName:  eek.gif
Views: 28
Size:  1.0 KBName:  eek.gif
Views: 28
Size:  1.0 KBName:  eek.gif
Views: 28
Size:  1.0 KB
All in all massively disproportional effects!
Some scary, some expensive realistic Name:  frown.gif
Views: 28
Size:  1.0 KB and some extremely silly Name:  biggrin.gif
Views: 19
Size:  1.0 KBexamples, hopefully instructive as well.

Therefore always measure current in a new or changed power system.
A watt-meter will pay for itself, several times over, bigly.

Last edited by ron_van_sommeren; 09-15-2022 at 12:52 AM.
Old 09-15-2022, 12:46 AM
  #4  
ron_van_sommeren
 
ron_van_sommeren's Avatar
 
Join Date: Sep 2002
Location: Nijmegen / Nederland
Posts: 591
Likes: 0
Received 15 Likes on 12 Posts
Default

Another thing to take into account ...
Power system derating
It is a good practice to have some headroom built in. Motor runs cooler, slightly more efficient too, and you have some leeway should things go south a bit.
About derating motors, controllers, batteries, electronics in general:
Vriendelijke groeten Ron
• Without a watt-meter you're in the dark ... until something starts to glow •
E-flight calculatorswatt-metersdiy motor tips&tricksCumulus MFC
The following users liked this post:
Cecil Webb (09-16-2022)
Old 09-16-2022, 05:08 AM
  #5  
ron_van_sommeren
 
ron_van_sommeren's Avatar
 
Join Date: Sep 2002
Location: Nijmegen / Nederland
Posts: 591
Likes: 0
Received 15 Likes on 12 Posts
Default

Using a controller with a higher voltage and/or current rating is not a problem.
That only carries a mass and size 'penalty'.

A controller does not 'force feed' the motor with current.
Only pitch, voltage², Kv³ & gearing³ and prop-diameter⁴ determine actual current, as described earlier in post_#3 above.

The rules are almost the same for power drawn, voltage excepted.
Power is drawn is proportional to voltage³.

At full throttle the controller his little/no effect on current and power drawn, it just passes on what the power system demands, even if it would lead to its fiery death.

Prettig weekend Ron

Last edited by ron_van_sommeren; 09-16-2022 at 05:11 AM.
The following users liked this post:
Cecil Webb (09-16-2022)

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.