Homeroasters - Home Roasting Coffee Community » CONSUMER ZONE » Equipment re-builds, reviews, fix it's and more
Who is here? 1 guest(s)
 Print Thread
Poppery I, fan but no heat
CoffeeFishingBeer
Top  #1 Print Post
Posted on 10/13/2012 6:16 PM
I have a Poppery I with separated fan and heat circuits (two power cords, switch has been removed).

In normal operation, each power cord is plugged into a power strip. The power strip for the heat circuit is plugged into a 100' outdoor extension cord which is plugged into wall current.

The power strip for the fan circuit is plugged into a variac that I used to boost the fan voltage (the heater drops the line voltage to about 104).

The other night I was warming up the popper and simultaneously preparing my beans, the fuse in the variac blew, leaving the popper running with heat but no fan. I hustled over there as soon as it registered, and it smelled very hot.

I unplugged the heat, plugged the fan directly into wall current, and cooled it down. Plugged the heat circuit in again, but no heat.

I've been through everything suggested in this thread:

http://forum.homeroasters.org/forum/viewthread.php?thread_id=1800&rowstart=0

Using my multimeter, I've determined that:

-I have continuity across the thermal cutout
-I have continuity across the thermostat, and the points are closed
-I have end to end continuity in the heating coil, from where it connects to the thermostat to the screw at the other end where it connects to the ceramic piece.

And yet, I have no heat. I'm not sure what else to test. Is it possible for the thermal cutout to be partially bad? That is damaged enough to not pass enough juice to the coil, but intact enough to indicate continuity?

I'm stumped, and at or beyond the limits of my electrical knowledge.

Thanks for any advice you might have,

Jonathan
 
allenb
Top  #2 Print Post
Posted on 10/13/2012 9:13 PM
Jonathan,

Check the resistance of the main heating coil (I'm assuming since the heat and fan are split you have bypassed the resistor coil). Report back with this ohms reading and we'll be better able to offer advice.

Also, how does the coil look? It only takes a second to self destruct.

Allen
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
CoffeeFishingBeer
Top  #3 Print Post
Posted on 10/14/2012 1:46 PM
Thanks, Allen.

I think I neglected to mention that during that post-mortem I found that the ceramic piece around which the coil wraps had cracked, and the line of the crack ran right through the screw hole that attaches the thermostat. It wasn't lke that the last time I'd had the popper opened up in the early spring when I separated the heat and fan circuits, so I'm attributing that to the overheating condition. I tried patching it together with JB Weld, but it doesn't seem to like to stick to clay very well. It just fell apart this morning when I tried to put it back in. Trying to juggle the two broken pieces into postion was pretty unsuccesful for an all-thumbs guy like me, so I think I'll relegate this one to being a parts cadaver.

If my "chancellor of the exchequer" will go for it, I may step up to a purpose-built roaster. I'd love to try a Hottop, but I doubt she'll go for that one lol.

I'm also considering building a Turbo Crazy for my next project. It looks like it's within my skill level and is pretty well documented. I'm moving in a month, though, so I may get by with buying good commercial coffee until then. I'm in the greater San Francisco area, so there's a lot to choose from.

Thanks again for your help!

Jonathan
 
Jump to Forum: