Problem with YEP (Hobby King) ESCs.

[Konrad]

This thread is to document a rash of problems I’ve been having with the YEP ESC sold by Hobby King. In the last month I’ve been setting up six models three have had an odd failure mode on the bench. The only thing common is that the three failed set ups were all using YEP, ESC with SBEC. It appears that on power up (when the battery is first plugged) in the YEP SBEC is allowing a voltage spike to pass through. This has been damaging the micro processors on the YEP ESC (will no longer respond to the programing card), the microprocessors in the RX and even those on the digital servo. Looking at the voltage output on an oscilloscope the voltage from the SBEC looks ok, relatively clean. Unfortunately I don’t have a tracer scope so I can’t track transient (spikes) issues. I’m looking to get access to one.

All three YEP ESC (30, 45 and 80 amp) were purchased in mid 2016 when Hobby King had a super deal of the YEP ESC.

While I’ve had good luck with the YEP brand in the past, I fear that there may have been an issue with a production run (some component in the SBEC out of spec ). As many may know some firms don’t make scrap, they just lower the price until the junk sells. I fear this may be the case here with the mid 2016 YEP ESC.

I’d like to ask the FT hive mind for any anecdotal evidence to suggest that YEP brand has had or is having a quality issue with their SBEC in their ESC.

TIA,

Konrad

 

[liamnave]

Can you link them? I am also having trouble with some of their 10amp ESCs

 

[PsyBorg]

Did some digging and saw that Yep brand esc's are made by Sunrise Model. A quick search for Sunrise Model speed controller issue netted a few forum posts and a warning from the manufacturer I saw several posts with the words sync issues and low volts.. you may start looking in that direction. There was also a warning to not use these with Scorpion motors as they fry the motors due to a sync issue.

There seems to be a theme with these and sync just with 10 minutes of digging.

 

[Konrad]

Did some digging and saw that Yep brand esc's are made by Sunrise Model. A quick search for Sunrise Model speed controller issue netted a few forum posts and a warning from the manufacturer I saw several posts with the words sync issues and low volts.. you may start looking in that direction. There was also a warning to not use these with Scorpion motors as they fry the motors due to a sync issue.

There seems to be a theme with these and sync just with 10 minutes of digging.

Thank you, this is helpful. I wasn’t aware who the OEM was.

Many (most) ESC have had issues with high impedance motor windings (high turn or low KV). What is happening is as the large coils collapse the induced voltage actually tries to drive to motor in reverse. This can wreak havoc with the commutation process as the rotor often is out of position when the ESC energizes the next set of windings. This is also an issue with the use of the freewheeling protection circuit at low power settings. While I love freewheeling circuits one needs to know their limitation. Using high PWM frequencies helps with the loss of synchronization, but at the expense of adding heat to the ESC. These commutation issues are why one should keep up to date with the firmware. I’ve had very good results with the latest firmware for the Castle Creation and ZTW Gecko ESC.

My understanding of the out of sync failure, is that induced voltage is high enough to cause reverse voltage break down of the ESC mosfet destroying it. As damage to the Metal Oxide Surface usually results in the mosfet failing in the on state (shorted). This fails the switch function of the esc which results in the battery voltage be applied constantly to the windings, burning up the motor. So it is my understanding that it is the high impedance motor that is destroying the ESC. The then failed ESC burns up the motor windings. This loss of commutation control is why you should never unplug the battery from a running brushless motor. As the windings (coils) collapse the high voltage spikes will destroy the uncontrolled mosfets.

As I’ve been using the YEP ESC in low impedance application like EDF and EF-1 pylon racers I have not seen this failure mode with the YEP. But I have hit the “Electrical RPM” limit with high pole count motors.

If there is anything unique to the Scorpion brand of motor (and I can’t think what that would be) one should see the same failures with the latest Hyperion GS, HS, ZS motors as Scorpion is the OEM.
Btw the reason we see such a low PWM frequency recommended for the Scorpion motors is that historically the Scorpion Commander series does not have PWM frequency higher than 9kHz.

I’ll look into the low voltage issue in more detail.

If anyone has info on the YEP SBEC please post here.

All the best,

Konrad