Fuji Controller Question
 

Hi,

I have a fuji PXR3 controller. When I went into the studio today to work, I saw the dreaded UUUU code on the controller. This has happened to me in the past, so I remembered that this means that the thermocoupler needs to be replaced. Well, that did not fix the problem. I am still getting the UUUU code after double checking all the wires and connections. I have done this several times, so I am pretty sure I did it right. Has anyone had any similar experience and any ideas of what to try next, short of ordering a new controller? Of course, I am getting ready for a show next weekend and have to get it up and running asap.

Thanks for any input!

Ellen

resolved this problem..thanks for the pm : )

Please share the fix for future reference.

yep, all uuuu are a tc break.

Mike

Yep..it is a break alright!

Replaced the thermocoupler and the only other thing is the rtd ( resistive thermal device )

a call to Fuji in the am, but probably a new controller : (

Maybe I should just look for a good deal on a new kiln, Mike?

Thanks,

Ellen

Mike,

With a new tc installed, is there any other possible fix, short of replacing the whole controller?

Thanks,
BTW, those are some beautiful kilns!

A new Fuji PXR-3 is about $75 plus postage. A new kiln 10 times as much plus shipping!

Hi there,

Where did you see the pxr-3 for that? That would make the decision much easier!

There was a fellow on eBay selling new PXR-3's with a SSR for $75 plus $8 shipping in Jan/Feb of this year.

Many thanks to PAM and Mike, my kiln will be up and running (with a new thermocouple) for my show. Thanks to Mike, I learned a lot too! Also think I have found my new Glass Hive kiln. Amazing, friendly customer service!

Thank you for all your helpful replies!

ellen

No problem, and thank you.

Ps. Its Pam and mike :)

Mike

Hi Ellen,

You are most welcome! Glad you will be able to get your show prep done. Hope it is a great one ;)


Beware, there are different kinds of PXR3's available out there. I get calls from folks who have bought the wrong model # for cheap, only to find out it does not work with the relays that are installed. That $50 added to the $159 for the real deal was not a savings in the end. You can send in the cheaper ones and get them redone to make them right for about $80, and two way shipping. There is also no warranty on them, so if they crap out you can't send it in for a free repair.

Remember, these controllers are made for all kinds of industry. I'd rather the one meant for Starbucks coffee machines is not the one installed in my kiln.

Also SSR (solid state relays) tend to fail in the ON position. That means a runaway kiln melting your work. The mechanical relays tend to fail in the OFF position which means you just anneal the work again. I'd rather run another cycle than chip glass of the kiln floor loosing a days kiln goodies. I can also hear the click of my mechanical relay, which gives me early warning if something goes wrong. Don't hear the click? Better go check on it. The SSR will give no audible sign of failure.

The thread makes it look more confusing that it was. The thermocouple was from way back before the ends were being welded (9+ years ago). The twist together ends corrode over time and loose conductivity. The problem can be fixed by welding the tip with a Tig welder. Any addition of any other metals will ruin the signal properties of the metals. Therefore Mig, stick, or oxy acetylene don't do the job.

Thermocouples are simple little monsters, if built right, will last a lifetime. The two wires are made of different kinds of metal that send electric signals at different rates. The comparison of the two wires by the controller is what the controller reads. If there is a break in connection the UUUU shows up on a Fuji.

It surprises me that some companies are still settling with the non-welded tips and super thin wires that need regular replacement. A good thing to look into before making the purchase. The thin wires also over work the relays causing a much shorter lifespan because the controller reads minute changes at a faster rate (faster than needed to hold a tight temp control). That is why some kilns eat relays. Replacing the wire in the chamber with a thicker gauge will solve that problem.

First check the connections on the leads to the thermocouple, then look at the end. The thin wired ones can break in the unstripped portion as well, another reason we don't use the floss size wires. If the company does not use thermocouple blocks between the wires in the chamber and the wires in the control box, it can also be heat weakened and break right there, or the insulation burns off allowing contact with the case.

I replace about 2 thermocouples a year from our company's products. They are always pre-weld era, and usually on a mail box that we haven't produced in, gosh, 10 years. For as many kilns as we produce a year, that is a very small percentage.

Thanks for all the tips, guys. Highly valuable even 10 years later.
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