Issue with Heater 1 Predicted Maximum Temperature Warning
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@droftarts
Ok.
So this will not affect the printing or the machine?
modal parameters means PID parameter? -
@R006 said in Issue with Heater 1 Predicted Maximum Temperature Warning:
So this will not affect the printing or the machine?
No, it's just a warning to say if you set it to a high temperature, while turning off limits such as M143 and M570, or the heater suffers from thermal runaway (possibly if there's a wiring fault), things are going to get very hot!
Ian
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@droftarts
okay,
Is there any way to re-solved this (like electronic end)? -
@R006 Can you post the exact error message? I misread your first post, where you said:
Heater 1 has reached a predicted ...
The usual error message is something like:
Warning: Heater 1 predicted maximum temperature at full power is 589°C
Obviously these are two quite different things. You should only get the message at startup. As far as I'm aware there's no way to disable it. It's just a warning. The only way to avoid it is to fit a lower power heater, and retune the heater.
Ian
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@droftarts
Warning: Heater 1 predicted maximum temperature at full power is 589°C
okay -
The warning is telling you what temperature it calculates as the maximum that could be reached in a failure condition where power was stuck on. It's up to you do mitigate that with a thermal fuse that could physically cut power to the heater when a temperature has been reached. They usually only cost a few cents and are used in everyday appliances that have heaters like kettles or toasters.
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thank you for the clarification. I will try for fuse, before that I have couple of questions more:
- If this warning appears, then it must appear every time for that machine or heater , right ?
- Is it possible to reduce "S" value in M307, so that it never uses 100% PWM & may not cause this effect?
note: My concerns is to remove this warning, so that client does not mis interpret this as a problem with the extruder heating.
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@R006 said in Issue with Heater 1 Predicted Maximum Temperature Warning:
- If this warning appears, then it must appear every time for that machine or heater , right ?
As far as I know, there's no way to remove the warning message. However, it only shows at startup, and as it is a warning, it will disappear after 5 seconds. And you will only see it on the PanelDue or in DWC if you are already connected.
- Is it possible to reduce "S" value in M307, so that it never uses 100% PWM & may not cause this effect?
That may remove the warning (though I'm not sure it will), but then your heater will take a lot longer to heat up, as it is using less power. It also doesn't protect you from a MOSFET or wiring failure, where the hot end would receive 100% power, and hit the temperature predicted.
The only real way around this is to fit a less powerful heater. But then, again, it will take longer to heat up.
Ian
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@droftarts
Okay,
I have two machine with same heater. but this warning message appears only in one machine. heater watt is 50.
So can i do something with its resistor value. -
@R006 If you get a warning that a heater could potentially reach a dangerous temperature, then the safest way to address this is to use a less powerful heater. Then if say a MOSFET failed, the heater would get hot, but not dangerously so.
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@R006 Are both machines running the same firmware version? Check in config.g what the M307 command is for each heater; they are probably different. If you have M501 in config.g, also check config-override.g for M307.
The code for the warning is here: https://github.com/Duet3D/RepRapFirmware/blob/1f1ce4c1adbce5bc32e141a1940c697b71e02c22/src/Heating/Heater.cpp#L237
The firmware makes a prediction, based on M307 parameters, what the highest temperature is. If this is higher than the maximum heater temperature (set by M143) - ambient temperature, then multiplied by 1.5 plus 50, you get the warning.
Ian