Temperature spikes

[jyalpert]

Hi all, I just ran my first 3 roasts on my new Huky!

All were 226g (1/2lb) on the perforated drum.  2 or 3 times during the roast, my thermometer registered a massive spike in temperature (see the one at 6:00 on the below graph).  Obviously this wasn't actually happening in the roaster, but I'm not sure exactly what's going on since it makes the curves look all wacky.  I have read about grounding issues, but I'm not sure if that's what this is.  Anyone have any suggestions?

[Gregr]

I saw a similar spike once but only once. I think it coincided with when I turned on the range hood fan- it shares the same outlet as the roaster motor, fan and fan dimmer. Only happened that one time- hopefully for you too.
Are you using a dimmer for your fan?

[jyalpert]

Currently yes, using a dimmer.  I ordered a Variac last night, though.  The fan is so friggin' strong, my settings for what I'd consider low/medium/high take place within a say 3mm range on the lower end of the dimmer, and I felt like I simply didn't have much control over what the fan was doing.

[Johnny4lsu]

Currently yes, using a dimmer.  I ordered a Variac last night, though.  The fan is so friggin' strong, my settings for what I'd consider low/medium/high take place within a say 3mm range on the lower end of the dimmer, and I felt like I simply didn't have much control over what the fan was doing.

The dimmer is probably what's causing it.

[Gregr]

Agreed- others have experienced the same thing. This is the dimmer I use and I've only seen that one weird spike:
http://www.ebay.com/itm/Variable-Fan-Speed-Controller-Speedster-Hydroponics-Inline-Fan-Exhaust-Air/400854550412?_trksid=p2047675.c100011.m1850&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D28791%26meid%3D31a3d76931ec4ca1b6eeed5c42930d0c%26pid%3D100011%26rk%3D5%26rkt%3D10%26sd%3D200526227800