Failure to hold heat

New roaster here. I seem to have an intermittent issue with the roaster maintaining temperature. During 3 separate roasts today- this occurred:
-150 g sample size
-roaster preheats normally to 230 C
-Roast begins
-At about 150 IBTS the ROR starts plummetting until it is in negative territory. (P is at 9, I lower fan to 2 or 1- no effect)
-The IBTS temp flatlines at 150 and never rises above.
-I dump yellow beans!

Any ideas what I am doing wrong

I don’t have answers for you since I’ve never roasted at 150g. However, on RoastWorld if you to the “Discover” option under “Roasts” you can filter on max/min of 150g roasts and get a search result of other folks’ 150g roast profiles. It may be a place to start to study profiles to give another roast plan a try and see if you still have the same issues. Or roast a 300/350g batch(which I think many of us do) and see if you have the same problem. If you do then something else with the roaster is going on. I can’t even tell if any of the other profiles are reasonable, but this one appears reasonable to me that might be helpful for you to either playback or do an overlay roast to see if you still run into the same problems with the roast.

I am fairly new to the bullet and also have never roasted 150g. I usually roast either 454g or 550g. I could be mistaken but it looks to me like your roasters heating is lowering or shutting down. Did you get any error messages or check the info button during any of your roasts.

The curves make no sense- it’s as though line voltage dropped to a very low level yet you apparently had no error code(s) (ErC). Going to P9 seems to have done nothing. It strikes me that the roaster may be running at lower than spec’ed line voltage. You can confirm that in Roast mode by clicking the “i” button (upper right) and verifying you have appropriate Net Line Voltage level for your Bullet (120 VAC or 220 VAC).

If line voltage is the culprit, an ErC should have been thrown. You can check for Error codes using the 2nd tab in the Info window (the “i” button mentioned above). Once the roaster has been shut off the codes are lost. However, the data including error codes will have been saved to the server. You should be able to reach out to Support and they can tell you what any errors were.

Bruce

I have checked your logs and unfortunately your induction board has some problem with the coil. Not a problem I have seen before for the 120V, so I think Aillio will want to have it back for inspection. Please contact them for a replacement.

Board V2.0 / Serial 5964 / Firmware 596
Info 29458: 2000
Info 29460: 925
Info 29468: 140
Info 29467: 102
Info 28672: 57671
Info 28673: 40564
Info 29696: 304
Error 32775 - Induction coil has a short circuit
Error 131: 67
Error 32775 - Induction coil has a short circuit
Error 131: 67
Error 32770: 2802
Error 32780: 7 - Induction no current
Error 131: 67
Error 32780: 7 - Induction no current
Error 131: 67

This looks like you are correct.

Had the exact same issue while roasting a while ago. Mine is a 230V, V2, Serial 002276.

Do we need to change the PCB. My coffee partner is currently near Bangalore and will be able to pick up a spare PCB from Kaapi machines if necessary. Please advise.

There is something with how the frequency heats the drum, may need to send the whole unit in to get properly calibrated induction heating.

Each drum has slightly different mass or properties, so the induction calibration has to be done in factory.

If anyone plans to use Bullet as their main roaster for work, it is ideal to have a second unit. That does increase the cost of investment to USD $7K for a 1Kg setup, but prevents down time and loss of customers.

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I think it was something to do with the ambient temperature, which, in my case was about 9°C. I let the roaster cool down, shut down. Then I disconnected the power cord, let the machine sit for a while and then restarted the machine without the external fan that I use below the induction board on. It started normally and I managed to complete four 1050gms roasts.

Too high or two low temps, both affect the induction performance I guess.

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WOW! Glad to hear that!

If I recall correctly, in the user manual they state there is a safety auto off if the temps are too low.

Furthermore, (not directing this at anyone specifically, just a general statement) subjecting anything to sub zero and excess of 200C is a lot of stress on parts. I try to keep the induction board above freezing and below boiling ambient temps. But good to hear that it can survive the frost. Alleviates some of the worry, as we get pretty cold weather sometimes.