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homeroaster
10/04/2022 7:11 PM
I'm still alive. Haven't posted here for a while. Still roasting about 20 lb a week. Life is good. Find me on Facebook.

allenb
10/03/2022 3:29 PM
carloswlkr Welcome

allenb
10/03/2022 12:06 PM
HI Michael, go to consumer zone, java trading company and first post is basic rules. PM me with any needed clarifications. Cheers

Michael Kirkpatrick
10/03/2022 11:47 AM
Good morning! what would be the best way to post a coffee roaster for sale? Thanks

renatoa
10/03/2022 2:12 AM
@ittiponcr and welcome cup adrianalindgren

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Mean Time To Failure for FB Elements
jbrux4

Quote

renatoa wrote:

Intrigued that the other terminal connection looks fine...
I would investigate how/what are they different...

I would try the following sandwich:
- washer
- element wire, cut to remove any rust and melted drops, then coiled around the screw in a single loop
- washer
- eyelet with AWG12 wire


I've got my high temp male spade connectors and ceramic washers. My sandwich will be as follows:
Ceramic element backer, element nichrome, male spade connector, ceramic washer, then screw head.

I am thinking I need to get a new element that has a fully in tact nicrome hook. The way I see it, once I cut the degraded nichrome hook off, what's next? What materials and what method could I use to extend the nichrome wire back around the screw?
R/
Jared
 
renatoa
Just pull some wire from the coil element itself, 2-3 cm shorter will not change dramatically the power.
 
jbrux4

Quote

renatoa wrote:

Just pull some wire from the coil element itself, 2-3 cm shorter will not change dramatically the power.


Gotcha. Thanks!!!

I will be putting it all back together again and testing. I think the new set-up removes most of the issues/risks.
R/
Jared
 
jbrux4
I redid the connections and the elements work. The problem now is that I have one runaway element meaning that once it gets plugged in it heats up. The TC4 or SSR stopped regulating the power?!?

The other element gets regulated just fine.

What would be a good approach to determining or finding the issue?

I have switched the elements to a particular power source, and the element that is hooked up to a particular run becomes the runaway element. I am putting my money on the SSR, but would def want to hear from the masters. Thanks.

Here is the wiring diagram....

forum.homeroasters.org/forum/attachments/elements_wiring-issue.jpg
jbrux4 attached the following image:
elements_wiring-issue.jpg

Edited by jbrux4 on 02/23/2020 3:58 PM
R/
Jared
 
shortyjacobs
When SSRs fail, they typically fail closed ("ON"). Likely, when the element shorted out and melted, it did some damage. The SSR may be toast. Try switching SSRs with each other - does the other element now run unregulated? Check the SSRs with a multimeter. When off, or disconnected, there should be no continuity across the high voltage side. If there is, that SSR is dead dead dead.
-Keith
 
jbrux4

Quote

shortyjacobs wrote:

When SSRs fail, they typically fail closed ("ON"). Likely, when the element shorted out and melted, it did some damage. The SSR may be toast. Try switching SSRs with each other - does the other element now run unregulated? Check the SSRs with a multimeter. When off, or disconnected, there should be no continuity across the high voltage side. If there is, that SSR is dead dead dead.


I just updated my previous post with just that scenario. Looks like I will be replacing the SSR. I don't have a voltage tester, but I prob don't need one with the evidence thus far. Thanks for the input.
R/
Jared
 
jbrux4
What I have solved is the electrical termination problem. No arcing or sparking this time. My sandwich is as follows: Element Ceramic Backer, Nichrome Wire, High Temp Male Spade Connector (I had to enlarge the hole diameter jusrt barely using a small drill bit and some pliers to hold the termination to keep it from spinning), mfr supplied washer (the ceramic ones are too brittle and crack under the slightest pressure), and the screw head.

Here is a pic:
forum.homeroasters.org/forum/attachments/male_spade.jpg

Male Spade Connectors: https://www.amazo...&psc=1
jbrux4 attached the following image:
male_spade.jpg

R/
Jared
 
jbrux4
The runaway element was fixed by replacing the SSR. Easy fix, but money I didn't want to have to spend. And, actually, with an element always at 100%, roasting was actually easier to maintain a good RoR. There were less "slight" adjustments needed and it was predictable. I did 4 roasts like that. Oh well, back to the norm. Besides, who wants to have to unplug an element at cool down? Perhaps a toggle switch...hmmmmm, maybe.

Couple things I learned from the SSR issue:
* Never leave it plugged in when not in use
* Always run the blower when plugging in the elements just in case an SSR is stuck in the "always on" position

Anyways - case closed. Thanks to the forum for helping again!!
R/
Jared
 
shortyjacobs
Yep. I use a contactor relay upstream of my SSRs for a "positive shutoff". Mains power to the SSRs is only enabled once the fans are running and a roast has begun, and I cut power to the SSRs at the end of the roast with the contactor to start the cooldown phase. I don't trust SSRs as a positive "off", since they are just semiconductor chips that can fail...I like air separating my contacts when it really matters.
-Keith
 
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