QUESTION ABOUT 350QX ESC

[Technut]

If an esc gets to hot to touch with motors not running does that indicate it is bad....2 out of 4 of mine do this. Any help would be appreciated

 

[holtneil]

Hi Mate they should not get hot at all , check for a short in power side and the 3 phase motor side , ESC will get warm in flight but if the right amps will not get hot , be careful hot ESC can catch on fire and pulling the battery may not stop the fire

 

[Technut]

That's what I was thinking! TY Holtneil for the backup.....

 

[holtneil]

George the other moderator is good on electronics message him it may be a fet going

 

[Technut]

TY I just might do that if I don't resolve the problem myself

 

[holtneil]

Keep us posted it help any one with the same problem , try swapping one esc that stays cool with the motor from one that comes from the ESC that gets hot , to see if its motor or esc that got the problem

 

[Technut]

Will do!

 

[GJH105775]

Sounds like Neil said a transistor may be going bad. open it up and see if one in particular is getting hotter, and check for cracks in the silicone and the solder.

 

[Technut]

I checked out my Esc's last night and found 3 to get so hot it would burn you. Didn't see any bad connections or loose solder. There was discoloration on bottoms of the 3 escs. Is there anyone who can repair these? It's probably cheaper to just replace them.

 

[GJH105775]

You can repair these if you find the problem, the ESC it's self is pretty simple. Finding where the problem is may prove hard. Do they only get hot under load (while a motor is connected), or even if you unplug the motors and send a signal to for them to power the motor?

 

[Technut]

The motors are not connected. With battery connected and switch on, after a few seconds the Esc's are almost too hot to handle.

 

[GJH105775]

The motors are not connected. With battery connected and switch on, after a few seconds the Esc's are almost too hot to handle.

Sounds like a short then, so this is even when the craft is not armed? Just when they get power? That makes me strongly think it s a slow short, meaning there is resistance (otherwise it would have melted everything in less than a second).

Can you provide some detailed pictures of the board that gets hot, on both sides?

 

[Jackson]

Did you get it from Horizon Hobby? Have you spoken to them? Going from one hot ESC to three sounds more like a symptom. You need to determine the actual, underlying cause, I doubt that replacing ESCs (at $33 a pop) will cure anything.

 

[GJH105775]

I checked out my Esc's last night and found 3 to get so hot it would burn you. Didn't see any bad connections or loose solder. There was discoloration on bottoms of the 3 escs. Is there anyone who can repair these? It's probably cheaper to just replace them.

Did you get it from Horizon Hobby? Have you spoken to them? Going from one hot ESC to three sounds more like a symptom. You need to determine the actual, underlying cause, I doubt that replacing ESCs (at $33 a pop) will cure anything.

If you meant 3 ESCs are getting hot, then check your PDB, and especially your solder joints, like Jackson said. If you meant 3 FETs were getting hot then sounds like a slow short in the ESC, it is possible to have a slow short in one ESC that affects the entire circuit, therefore heating up the other ESCs, but usually that will mean one ESC is significantly hotter than the others, and all of the ESCs would be getting somewhat warn, not just 3.