PID tuning : 3.5.0-rc.2+101 issue
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Im trying to PID tune a dry box which
is insulated and is heated with a PTC Heater 220V 100W Ceramic Heateri get this fault with the following PID tune
Heater 3 fault: temperature rising too slowly: expected 0.13°C/sec measured 0.03°C/sec
PID tune results
1/1/2024, 12:05:50 AM Warning: heater behaviour was not consistent during tuning
Auto tuning heater 3 completed after 3 idle and 25 tuning cycles in 4301 seconds. This heater needs the following M307 command:
M307 H3 R0.244 K0.866:0.000 D7.60 E1.35 S1.00 B0
Edit the M307 H3 command in config.g to match this. Omit the V parameter if the heater is not powered from VIN.
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@moth4017 Is this new with RC2? If not what results did you get with RC1?
Looking at your graph I'd say the message is correct. If you look at the shape of the heating zigzags I'd say that they are not identical. I've no idea why that would be, but my understanding is the PTC heaters can be tricky to tune. Do you have any issues if you just use the figures that have been reported?
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@gloomyandy i get a heater fault the first time it heats up to 60C
Heater 3 fault: temperature rising too slowly: expected 0.13°C/sec measured 0.03°C/sec
the way im getting around it at the moment is to set the heater to 50C then 55C then 60C with about 5 minutes between each setting<
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@moth4017 What about my other questions? Is this new in RC2?
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@moth4017 If you look at the graph you can see that it for some reason the heating rate is much lower during the initial heatup than it is when close to temperature, so I'd say the errors are correct. You may need to set the parameters manually, or use the workaround that you currently have.
Maybe @dc42 has some thought on what is happening with this heater?
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@moth4017 yes the latest one
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i just did another switch on from ambient so i could capture the point at which the error happends
you can see just above the error the temperature reached 38C and requested 60C ,
PTC heater wave for a 15C rise , with PWM at 100%
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@moth4017 You still have not answered my question. Is this a new problem? Did you run the same tuning under RC1 (or any earlier version), if so what results did you get?
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@gloomyandy not sure it may have always been there ive only just finished setting up the dry box
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@moth4017 This is totally off-topic, but have you intentionally disabled text/font smoothing for some reason? =S
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@Exerqtor If i new what that was i may be able to answer
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@moth4017 can anyone suggest some other work arounds for the the PID values to help out with the PTC heaters?
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@moth4017 has anyone done a PID tune algorithm for PTC heaters?
