Heater fault on heated bed because it's rising to slow.

Exerqtor

Didn't have time to test yesterday, so i just tried a heatup and :

Error: Heater 0 fault: at 64.9°C temperature is rising at 0.4°C/sec, well below the expected 0.7°C/sec

So i get the feeling the tuning outputs a higher than realistic heating rate to be honest.

pfn

@arnold_r_clark

I'm also seeing similar behavior since updating to 3.4.0b6 (from 3.3.0)

My bed heater faults very often while initially warming up. And I can also clear the fault and continue heating, but very annoying.

Re-running PID tuning did not improve the situation.

SIam

Hi,

Try to use the half of the computed R value from the PID Tuning, This is how it works with my printer

https://forum.duet3d.com/topic/25321/bed-heater-fault-3-4-b5

gloomyandy

@pfn There are quite a few fixes post beta6: https://github.com/Duet3D/RepRapFirmware/commits/3.4-dev

Some of these may impact the problem you are seeing...
https://github.com/Duet3D/RepRapFirmware/commit/37b4e02726993763b477181b6aa918089e2210b4
https://github.com/Duet3D/RepRapFirmware/commit/1e0e6c99252dee6aa20194f212aca3be6e68415a

0

dc42 committed to Duet3D/RepRapFirmware

Fixed heater fault detection while heating up

Also shortened the M307 response so that it fits in the reply buffer

0

dc42 committed to Duet3D/RepRapFirmware

Fixed bug in calculation of heater PID parameters

pfn

@gloomyandy thanks for digging! looks like known issues that will be resolved in the next beta/rc

Exerqtor

@gloomyandy

Well there you go, just have to adjust the heating rate until b7 / RC1 sees day then

Gixxerfast

@gloomyandy Thanks for the info.

I thought that my Nevermore carbon recirculation filter with fans was responisble for the heater errors.

Looking forward to the next beta release then

gloomyandy

@gixxerfast Just to be clear, I'm not saying that the above changes will fix the problem, just that some things have been changed! Will need to be tested with the next release I guess?

Exerqtor

@gloomyandy said in Heater fault on heated bed because it's rising to slow.:

@gixxerfast Just to be clear, I'm not saying that the above changes will fix the problem, just that some things have been changed! Will need to be tested with the next release I guess?

@dc42 Guess this is something you could either confirm or deny?

hestiahuang

Heater 0 fault: temperature rising too slowly: expected 0.44°C/sec measured 0.21°C/sec

Build the new source code after Beta6, the same.

Heater 0 fault: temperature rising too slowly: expected 0.44°C/sec measured 0.21°C/sec

dc42

@hestiahuang did you run M303 heater tuning on the bed heater, and save the M307 result?

hestiahuang

@dc42
yes, I did. Ran Auto PID and saved, also restarted. But still failed, even I used bangbang mode, full speed, I mean.

After above, I got this too

Then I changed the code and built Beta7 version, everything looks good now.
I adjusted the factor 0.5 to small value simplely => RepRapFirmware\src\Heating\LocalHeater.cpp => Line#317 => if (actualTemperatureRise < expectedTemperatureRise * 0.5)

hestiahuang

@dc42 I guess this should be new good feature, it will be perfect if it is better to enlarge the limitation. Or can have parameter to set expected rate.

hestiahuang

Need to resume my printer can print first, so I call it simple way...

hestiahuang

@dc42
Read from change history, issue is involved from Beta3 and keeping improving.

hestiahuang

@dc42
similar topics
https://forum.duet3d.com/topic/24842/rrf-3-4b3-bed-heater-fault/14?_=1639653214558
https://forum.duet3d.com/topic/24809/3-4-0-beta-3-heater-0-fault/12

dc42

@hestiahuang we have made changes in 3.4.0beta 7 that we believe resolve the majority of these cases.

hestiahuang

@dc42 You did great! Thank you so much!

joeko

now with beta7 i also get this error. with rrf 3.3 all was fine

Exerqtor

@joeko
Have you re tuned the heater after upgrading to b7? I haven't gotten around to test mine btw, so just asking out of curiosity